The male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans and in some other male-heterogametic species in which the homologue of the X chromosome has been retained.
The human male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans.
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Any method used for determining the location of and relative distances between genes on a chromosome.
The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.
The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
Staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes. Applications include the determination of chromosome rearrangements in malformation syndromes and cancer, the chemistry of chromosome segments, chromosome changes during evolution, and, in conjunction with cell hybridization studies, chromosome mapping.
Abnormal number or structure of the SEX CHROMOSOMES. Some sex chromosome aberrations are associated with SEX CHROMOSOME DISORDERS and SEX CHROMOSOME DISORDERS OF SEX DEVELOPMENT.
Actual loss of portion of a chromosome.
Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.
Genes that are located on the Y CHROMOSOME.
Very long DNA molecules and associated proteins, HISTONES, and non-histone chromosomal proteins (CHROMOSOMAL PROTEINS, NON-HISTONE). Normally 46 chromosomes, including two sex chromosomes are found in the nucleus of human cells. They carry the hereditary information of the individual.
A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.
The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.
A transcription factor that plays an essential role in the development of the TESTES. It is encoded by a gene on the Y chromosome and contains a specific HMG-BOX DOMAIN that is found within members of the SOX family of transcription factors.
Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.
Mapping of the KARYOTYPE of a cell.
The human female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in humans.
Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.
A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.
A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.
A specific pair GROUP C CHROMSOMES of the human chromosome classification.
Congenital conditions of atypical sexual development associated with abnormal sex chromosome constitutions including MONOSOMY; TRISOMY; and MOSAICISM.
The alignment of CHROMOSOMES at homologous sequences.
A specific pair of GROUP C CHROMSOMES of the human chromosome classification.
Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of MAMMALS.
A condition of suboptimal concentration of SPERMATOZOA in the ejaculated SEMEN to ensure successful FERTILIZATION of an OVUM. In humans, oligospermia is defined as a sperm count below 20 million per milliliter semen.
Structures within the nucleus of fungal cells consisting of or containing DNA, which carry genetic information essential to the cell.
DNA constructs that are composed of, at least, a REPLICATION ORIGIN, for successful replication, propagation to and maintenance as an extra chromosome in bacteria. In addition, they can carry large amounts (about 200 kilobases) of other sequence for a variety of bioengineering purposes.
The medium-sized, submetacentric human chromosomes, called group C in the human chromosome classification. This group consists of chromosome pairs 6, 7, 8, 9, 10, 11, and 12 and the X chromosome.
A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.
Proteins found in SEMEN. Major seminal plasma proteins are secretory proteins from the male sex accessory glands, such as the SEMINAL VESICLES and the PROSTATE. They include the seminal vesicle-specific antigen, an ejaculate clotting protein; and the PROSTATE-SPECIFIC ANTIGEN, a protease and an esterase.
A technique for visualizing CHROMOSOME ABERRATIONS using fluorescently labeled DNA probes which are hybridized to chromosomal DNA. Multiple fluorochromes may be attached to the probes. Upon hybridization, this produces a multicolored, or painted, effect with a unique color at each site of hybridization. This technique may also be used to identify cross-species homology by labeling probes from one species for hybridization with chromosomes from another species.
A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.
A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.
A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.
A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.
Clinical conditions caused by an abnormal chromosome constitution in which there is extra or missing chromosome material (either a whole chromosome or a chromosome segment). (from Thompson et al., Genetics in Medicine, 5th ed, p429)
The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.
A plant genus of the family CARYOPHYLLACEAE. The common name of campion is also used with LYCHNIS. The common name of 'pink' can be confused with other plants.
The primary testis-determining gene in mammalians, located on the Y CHROMOSOME. It codes for a high mobility group box transcription factor (TRANSCRIPTION FACTORS) which initiates the development of the TESTES from the embryonic GONADS.
A specific pair of GROUP B CHROMOSOMES of the human chromosome classification.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
A condition of having no sperm present in the ejaculate (SEMEN).
The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.
The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.
The large, metacentric human chromosomes, called group A in the human chromosome classification. This group consists of chromosome pairs 1, 2, and 3.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
Validation of the SEX of an individual by inspection of the GONADS and/or by genetic tests.
One of the two pairs of human chromosomes in the group B class (CHROMOSOMES, HUMAN, 4-5).
The mechanisms by which the SEX of an individual's GONADS are fixed.
Short tracts of DNA sequence that are used as landmarks in GENOME mapping. In most instances, 200 to 500 base pairs of sequence define a Sequence Tagged Site (STS) that is operationally unique in the human genome (i.e., can be specifically detected by the polymerase chain reaction in the presence of all other genomic sequences). The overwhelming advantage of STSs over mapping landmarks defined in other ways is that the means of testing for the presence of a particular STS can be completely described as information in a database.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.
Structures within the CELL NUCLEUS of insect cells containing DNA.
A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).
A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.
Aberrant chromosomes with no ends, i.e., circular.
The short, submetacentric human chromosomes, called group E in the human chromosome classification. This group consists of chromosome pairs 16, 17, and 18.
A type of chromosomal aberration involving DNA BREAKS. Chromosome breakage can result in CHROMOSOMAL TRANSLOCATION; CHROMOSOME INVERSION; or SEQUENCE DELETION.
A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.
Chromosomes in which fragments of exogenous DNA ranging in length up to several hundred kilobase pairs have been cloned into yeast through ligation to vector sequences. These artificial chromosomes are used extensively in molecular biology for the construction of comprehensive genomic libraries of higher organisms.
The short, acrocentric human chromosomes, called group G in the human chromosome classification. This group consists of chromosome pairs 21 and 22 and the Y chromosome.
An aberration in which a chromosomal segment is deleted and reinserted in the same place but turned 180 degrees from its original orientation, so that the gene sequence for the segment is reversed with respect to that of the rest of the chromosome.
A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.
The medium-sized, acrocentric human chromosomes, called group D in the human chromosome classification. This group consists of chromosome pairs 13, 14, and 15.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.
The total genetic information possessed by the reproductive members of a POPULATION of sexually reproducing organisms.
Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.
The occurrence in an individual of two or more cell populations of different chromosomal constitutions, derived from a single ZYGOTE, as opposed to CHIMERISM in which the different cell populations are derived from more than one zygote.
Genotypic differences observed among individuals in a population.
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.
A dosage compensation process occurring at an early embryonic stage in mammalian development whereby, at random, one X CHROMOSOME of the pair is repressed in the somatic cells of females.
The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.
The mechanisms of eukaryotic CELLS that place or keep the CHROMOSOMES in a particular SUBNUCLEAR SPACE.
The short, metacentric human chromosomes, called group F in the human chromosome classification. This group consists of chromosome pairs 19 and 20.
Any cell, other than a ZYGOTE, that contains elements (such as NUCLEI and CYTOPLASM) from two or more different cells, usually produced by artificial CELL FUSION.
The large, submetacentric human chromosomes, called group B in the human chromosome classification. This group consists of chromosome pairs 4 and 5.
The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).
Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.
A syndrome of defective gonadal development in phenotypic females associated with the karyotype 45,X (or 45,XO). Patients generally are of short stature with undifferentiated GONADS (streak gonads), SEXUAL INFANTILISM, HYPOGONADISM, webbing of the neck, cubitus valgus, elevated GONADOTROPINS, decreased ESTRADIOL level in blood, and CONGENITAL HEART DEFECTS. NOONAN SYNDROME (also called Pseudo-Turner Syndrome and Male Turner Syndrome) resembles this disorder; however, it occurs in males and females with a normal karyotype and is inherited as an autosomal dominant.
The relationships of groups of organisms as reflected by their genetic makeup.
Clinical conditions caused by an abnormal sex chromosome constitution (SEX CHROMOSOME ABERRATIONS), in which there is extra or missing sex chromosome material (either a whole chromosome or a chromosome segment).
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Structures which are contained in or part of CHROMOSOMES.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.
In gonochoristic organisms, congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. Effects from exposure to abnormal levels of GONADAL HORMONES in the maternal environment, or disruption of the function of those hormones by ENDOCRINE DISRUPTORS are included.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
The phase of cell nucleus division following PROMETAPHASE, in which the CHROMOSOMES line up across the equatorial plane of the SPINDLE APPARATUS prior to separation.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.
Highly repetitive DNA sequences found in HETEROCHROMATIN, mainly near centromeres. They are composed of simple sequences (very short) (see MINISATELLITE REPEATS) repeated in tandem many times to form large blocks of sequence. Additionally, following the accumulation of mutations, these blocks of repeats have been repeated in tandem themselves. The degree of repetition is on the order of 1000 to 10 million at each locus. Loci are few, usually one or two per chromosome. They were called satellites since in density gradients, they often sediment as distinct, satellite bands separate from the bulk of genomic DNA owing to a distinct BASE COMPOSITION.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.
Chromosome regions that are loosely packaged and more accessible to RNA polymerases than HETEROCHROMATIN. These regions also stain differentially in CHROMOSOME BANDING preparations.
The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)
In the interphase nucleus, a condensed mass of chromatin representing an inactivated X chromosome. Each X CHROMOSOME, in excess of one, forms sex chromatin (Barr body) in the mammalian nucleus. (from King & Stansfield, A Dictionary of Genetics, 4th ed)
Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.
Male germ cells derived from SPERMATOGONIA. The euploid primary spermatocytes undergo MEIOSIS and give rise to the haploid secondary spermatocytes which in turn give rise to SPERMATIDS.
The failure of homologous CHROMOSOMES or CHROMATIDS to segregate during MITOSIS or MEIOSIS with the result that one daughter cell has both of a pair of parental chromosomes or chromatids and the other has none.
The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.
The process of leaving one's country to establish residence in a foreign country.
A form of male HYPOGONADISM, characterized by the presence of an extra X CHROMOSOME, small TESTES, seminiferous tubule dysgenesis, elevated levels of GONADOTROPINS, low serum TESTOSTERONE, underdeveloped secondary sex characteristics, and male infertility (INFERTILITY, MALE). Patients tend to have long legs and a slim, tall stature. GYNECOMASTIA is present in many of the patients. The classic form has the karyotype 47,XXY. Several karyotype variants include 48,XXYY; 48,XXXY; 49,XXXXY, and mosaic patterns ( 46,XY/47,XXY; 47,XXY/48,XXXY, etc.).
The possession of a third chromosome of any one type in an otherwise diploid cell.
A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
An aberration in which an extra chromosome or a chromosomal segment is made.
Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.
A complex neoplasm composed of a mixture of gonadal elements, such as large primordial GERM CELLS, immature SERTOLI CELLS or GRANULOSA CELLS of the sex cord, and gonadal stromal cells. Gonadoblastomas are most often associated with gonadal dysgenesis, 46, XY.
Genes that are located on the X CHROMOSOME.
The full set of CHROMOSOMES presented as a systematized array of METAPHASE chromosomes from a photomicrograph of a single CELL NUCLEUS arranged in pairs in descending order of size and according to the position of the CENTROMERE. (From Stedman, 25th ed)
A number of syndromes with defective gonadal developments such as streak GONADS and dysgenetic testes or ovaries. The spectrum of gonadal and sexual abnormalities is reflected in their varied sex chromosome (SEX CHROMOSOMES) constitution as shown by the karyotypes of 45,X monosomy (TURNER SYNDROME); 46,XX (GONADAL DYSGENESIS, 46XX); 46,XY (GONADAL DYSGENESIS, 46,XY); and sex chromosome MOSAICISM; (GONADAL DYSGENESIS, MIXED). Their phenotypes range from female, through ambiguous, to male. This concept includes gonadal agenesis.
The total relative probability, expressed on a logarithmic scale, that a linkage relationship exists among selected loci. Lod is an acronym for "logarithmic odds."
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
A region, north-central Asia, largely in Russia. It extends from the Ural Mountains to the Pacific Ocean and from the Arctic Ocean to central Kazakhstan and the borders of China and Mongolia.
A plant genus of the family Caricaceae, order Violales, subclass Dilleniidae, class Magnoliopsida. It is the source of edible fruit and PAPAIN.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
Copies of DNA sequences which lie adjacent to each other in the same orientation (direct tandem repeats) or in the opposite direction to each other (INVERTED TANDEM REPEATS).
Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.
The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.
Abnormal genetic constitution in males characterized by an extra Y chromosome.
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.
The collective name for the islands of the central Pacific Ocean, including the Austral Islands, Cook Islands, Easter Island, HAWAII; NEW ZEALAND; Phoenix Islands, PITCAIRN ISLAND; SAMOA; TONGA; Tuamotu Archipelago, Wake Island, and Wallis and Futuna Islands. Polynesians are of the Caucasoid race, but many are of mixed origin. Polynesia is from the Greek poly, many + nesos, island, with reference to the many islands in the group. (From Webster's New Geographical Dictionary, 1988, p966 & Room, Brewer's Dictionary of Names, 1992, p426)
A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.
Genes bearing close resemblance to known genes at different loci, but rendered non-functional by additions or deletions in structure that prevent normal transcription or translation. When lacking introns and containing a poly-A segment near the downstream end (as a result of reverse copying from processed nuclear RNA into double-stranded DNA), they are called processed genes.
A terminal section of a chromosome which has a specialized structure and which is involved in chromosomal replication and stability. Its length is believed to be a few hundred base pairs.
PHENOTHIAZINES with an amino group at the 3-position that are green crystals or powder. They are used as biological stains.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
A type of defective gonadal development in patients with a wide spectrum of chromosomal mosaic variants. Their karyotypes are of partial sex chromosome monosomy resulting from an absence or an abnormal second sex chromosome (X or Y). Karyotypes include 45,X/46,XX; 45,X/46,XX/47,XXX; 46,XXp-; 45,X/46,XY; 45,X/47,XYY; 46,XYpi; etc. The spectrum of phenotypes may range from phenotypic female to phenotypic male including variations in gonads and internal and external genitalia, depending on the ratio in each gonad of 45,X primordial germ cells to those with normal 46,XX or 46,XY constitution.
A small aquatic oviparous mammal of the order Monotremata found in Australia and Tasmania.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
The first phase of cell nucleus division, in which the CHROMOSOMES become visible, the CELL NUCLEUS starts to lose its identity, the SPINDLE APPARATUS appears, and the CENTRIOLES migrate toward opposite poles.
The portion of chromosome material that remains condensed and is transcriptionally inactive during INTERPHASE.
A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.
Examination of CHROMOSOMES to diagnose, classify, screen for, or manage genetic diseases and abnormalities. Following preparation of the sample, KARYOTYPING is performed and/or the specific chromosomes are analyzed.
The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)
A subdiscipline of genetics which deals with the cytological and molecular analysis of the CHROMOSOMES, and location of the GENES on chromosomes, and the movements of chromosomes during the CELL CYCLE.
The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.
The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.
The capacity to conceive or to induce conception. It may refer to either the male or female.
The functional hereditary units of INSECTS.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
A plant genus of the family POLYGONACEAE that contains patientosides and other naphthalene glycosides.
The chromosomal constitution of cells, in which each type of CHROMOSOME is represented once. Symbol: N.
The number of males per 100 females.
Individual members of South American ethnic groups with historic ancestral origins in Asia.
DNA constructs that are composed of, at least, all elements, such as a REPLICATION ORIGIN; TELOMERE; and CENTROMERE, required for successful replication, propagation to and maintainance in progeny human cells. In addition, they are constructed to carry other sequences for analysis or gene transfer.
Large multiprotein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase in the cell cycle.
Plasmids containing at least one cos (cohesive-end site) of PHAGE LAMBDA. They are used as cloning vehicles.
A subclass of purinergic P2Y receptors that have a preference for ATP and ADP. The activated P2Y1 receptor signals through the G-PROTEIN-coupled activation of PHOSPHOLIPASE C and mobilization of intracellular CALCIUM.
Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.
The religion of the Jews characterized by belief in one God and in the mission of the Jews to teach the Fatherhood of God as revealed in the Hebrew Scriptures. (Webster, 3d ed)
A technique with which an unknown region of a chromosome can be explored. It is generally used to isolate a locus of interest for which no probe is available but that is known to be linked to a gene which has been identified and cloned. A fragment containing a known gene is selected and used as a probe to identify other overlapping fragments which contain the same gene. The nucleotide sequences of these fragments can then be characterized. This process continues for the length of the chromosome.
Nucleoproteins, which in contrast to HISTONES, are acid insoluble. They are involved in chromosomal functions; e.g. they bind selectively to DNA, stimulate transcription resulting in tissue-specific RNA synthesis and undergo specific changes in response to various hormones or phytomitogens.
The process in developing sex- or gender-specific tissue, organ, or function after SEX DETERMINATION PROCESSES have set the sex of the GONADS. Major areas of sex differentiation occur in the reproductive tract (GENITALIA) and the brain.
DNA constructs that are composed of, at least, elements such as a REPLICATION ORIGIN; TELOMERE; and CENTROMERE, that are required for successful replication, propagation to and maintenance in progeny cells. In addition, they are constructed to carry other sequences for analysis or gene transfer.
A sex-specific cell surface antigen produced by the sex-determining gene of the Y chromosome in mammals. It causes syngeneic grafts from males to females to be rejected and interacts with somatic elements of the embryologic undifferentiated gonad to produce testicular organogenesis.
The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.
A phenomenon that is observed when a small subgroup of a larger POPULATION establishes itself as a separate and isolated entity. The subgroup's GENE POOL carries only a fraction of the genetic diversity of the parental population resulting in an increased frequency of certain diseases in the subgroup, especially those diseases known to be autosomal recessive.
A family of the order Rodentia containing 250 genera including the two genera Mus (MICE) and Rattus (RATS), from which the laboratory inbred strains are developed. The fifteen subfamilies are SIGMODONTINAE (New World mice and rats), CRICETINAE, Spalacinae, Myospalacinae, Lophiomyinae, ARVICOLINAE, Platacanthomyinae, Nesomyinae, Otomyinae, Rhizomyinae, GERBILLINAE, Dendromurinae, Cricetomyinae, MURINAE (Old World mice and rats), and Hydromyinae.
An increased tendency to acquire CHROMOSOME ABERRATIONS when various processes involved in chromosome replication, repair, or segregation are dysfunctional.
A microtubule structure that forms during CELL DIVISION. It consists of two SPINDLE POLES, and sets of MICROTUBULES that may include the astral microtubules, the polar microtubules, and the kinetochore microtubules.
Overlapping of cloned or sequenced DNA to construct a continuous region of a gene, chromosome or genome.
The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.
Genetic mechanisms that allow GENES to be expressed at a similar level irrespective of their GENE DOSAGE. This term is usually used in discussing genes that lie on the SEX CHROMOSOMES. Because the sex chromosomes are only partially homologous, there is a different copy number, i.e., dosage, of these genes in males vs. females. In DROSOPHILA, dosage compensation is accomplished by hypertranscription of genes located on the X CHROMOSOME. In mammals, dosage compensation of X chromosome genes is accomplished by random X CHROMOSOME INACTIVATION of one of the two X chromosomes in the female.
Susceptibility of chromosomes to breakage leading to translocation; CHROMOSOME INVERSION; SEQUENCE DELETION; or other CHROMOSOME BREAKAGE related aberrations.
The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.
An individual having different alleles at one or more loci regarding a specific character.
Genetic loci associated with a QUANTITATIVE TRAIT.
The common chimpanzee, a species of the genus Pan, family HOMINIDAE. It lives in Africa, primarily in the tropical rainforests. There are a number of recognized subspecies.
The collective name for the islands of the Pacific Ocean northeast of Australia, including NEW CALEDONIA; VANUATU; New Hebrides, Solomon Islands, Admiralty Islands, Bismarck Archipelago, FIJI, etc. Melanesia (from the Greek melas, black + nesos, island) is so called from the black color of the natives who are generally considered to be descended originally from the Negroid Papuans and the Polynesians or Malays. (From Webster's New Geographical Dictionary, 1988, p748 & Room, Brewer's Dictionary of Names, 1992, p344)
The locations in specific DNA sequences where CHROMOSOME BREAKS have occurred.
Defects in the SEX DETERMINATION PROCESS in 46, XY individuals that result in abnormal gonadal development and deficiencies in TESTOSTERONE and subsequently ANTIMULLERIAN HORMONE or other factors required for normal male sex development. This leads to the development of female phenotypes (male to female sex reversal), normal to tall stature, and bilateral streak or dysgenic gonads which are susceptible to GONADAL TISSUE NEOPLASMS. An XY gonadal dysgenesis is associated with structural abnormalities on the Y CHROMOSOME, a mutation in the GENE, SRY, or a mutation in other autosomal genes that are involved in sex determination.
The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.
The only genus in the family Oryziinae, order BELONIFORMES. Oryzias are egg-layers; other fish of the same order are livebearers. Oryzias are used extensively in testing carcinogens.
The geographical area of Africa comprising ALGERIA; EGYPT; LIBYA; MOROCCO; and TUNISIA. It includes also the vast deserts and oases of the Sahara. It is often referred to as North Africa, French-speaking Africa, or the Maghreb. (From Webster's New Geographical Dictionary, 1988, p856)
Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.
Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.

Mitotic recombination in the heterochromatin of the sex chromosomes of Drosophila melanogaster. (1/1444)

The frequency of spontaneous and X-ray-induced mitotic recombination involving the Y chromosome has been studied in individuals with a marked Y chromosome arm and different XY compound chromosomes. The genotypes used include X chromosomes with different amounts of X heterochromatin and either or both arms of the Y chromosome attached to either side of the centromere. Individuals with two Y chromosomes have also been studied. The results show that the bulk of mitotic recombination takes place between homologous regions.  (+info)

Germ cell development in the XXY mouse: evidence that X chromosome reactivation is independent of sexual differentiation. (2/1444)

Prior to entry into meiosis, XX germ cells in the fetal ovary undergo X chromosome reactivation. The signal for reactivation is thought to emanate from the genital ridge, but it is unclear whether it is specific to the developing ovary. To determine whether the signals are present in the developing testis as well as the ovary, we examined the expression of X-linked genes in germ cells from XXY male mice. To facilitate this analysis, we generated XXY and XX fetuses carrying X chromosomes that were differentially marked and subject to nonrandom inactivation. This pattern of nonrandom inactivation was maintained in somatic cells but, in XX as well as XXY fetuses, both parental alleles were expressed in germ cell-enriched cell populations. Because testis differentiation is temporally and morphologically normal in the XXY testis and because all germ cells embark upon a male pathway of development, these results provide compelling evidence that X chromosome reactivation in fetal germ cells is independent of the somatic events of sexual differentiation. Proper X chromosome dosage is essential for the normal fertility of male mammals, and abnormalities in germ cell development are apparent in the XXY testis within several days of X reactivation. Studies of exceptional germ cells that survive in the postnatal XXY testis demonstrated that surviving germ cells are exclusively XY and result from rare nondisjunctional events that give rise to clones of XY cells.  (+info)

Sexual dimorphism in white campion: complex control of carpel number is revealed by y chromosome deletions. (3/1444)

Sexual dimorphism in the dioecious plant white campion (Silene latifolia = Melandrium album) is under the control of two main regions on the Y chromosome. One such region, encoding the gynoecium-suppressing function (GSF), is responsible for the arrest of carpel initiation in male flowers. To generate chromosomal deletions, we used pollen irradiation in male plants to produce hermaphroditic mutants (bsx mutants) in which carpel development was restored. The mutants resulted from alterations in at least two GSF chromosomal regions, one autosomal and one located on the distal half of the (p)-arm of the Y chromosome. The two mutations affected carpel development independently, each mutation showing incomplete penetrance and variegation, albeit at significantly different levels. During successive meiotic generations, a progressive increase in penetrance and a reduction in variegation levels were observed and quantified at the level of the Y-linked GSF (GSF-Y). Possible mechanisms are proposed to explain the behavior of the bsx mutations: epigenetic regulation or/and second-site mutation of modifier genes. In addition, studies on the inheritance of the hermaphroditic trait showed that, unlike wild-type Y chromosomes, deleted Y chromosomes can be transmitted through both the male and the female lines. Altogether, these findings bring experimental support, on the one hand, to the existence on the Y chromosome of genic meiotic drive function(s) and, on the other hand, to models that consider that dioecy evolved through multiple mutation events. As such, the GSF is actually a system containing more than one locus and whose primary component is located on the Y chromosome.  (+info)

Sexual dimorphism in white campion: deletion on the Y chromosome results in a floral asexual phenotype. (4/1444)

White campion is a dioecious plant with heteromorphic X and Y sex chromosomes. In male plants, a filamentous structure replaces the pistil, while in female plants the stamens degenerate early in flower development. Asexual (asx) mutants, cumulating the two developmental defects that characterize the sexual dimorphism in this species, were produced by gamma ray irradiation of pollen and screening in the M1 generation. The mutants harbor a novel type of mutation affecting an early function in sporogenous/parietal cell differentiation within the anther. The function is called stamen-promoting function (SPF). The mutants are shown to result from interstitial deletions on the Y chromosome. We present evidence that such deletions tentatively cover the central domain on the (p)-arm of the Y chromosome (Y2 region). By comparing stamen development in wild-type female and asx mutant flowers we show that they share the same block in anther development, which results in the production of vestigial anthers. The data suggest that the SPF, a key function(s) controlling the sporogenous/parietal specialization in premeiotic anthers, is genuinely missing in females (XX constitution). We argue that this is the earliest function in the male program that is Y-linked and is likely responsible for "male dimorphism" (sexual dimorphism in the third floral whorl) in white campion. More generally, the reported results improve our knowledge of the structural and functional organization of the Y chromosome and favor the view that sex determination in this species results primarily from a trigger signal on the Y chromosome (Y1 region) that suppresses female development. The default state is therefore the ancestral hermaphroditic state.  (+info)

Y chromosome and male infertility. (5/1444)

Recent genome analysis of the Y chromosome has increased the number of genes found on this chromosome markedly. Many of these genes in the part of the Y chromosome that does not undergo recombination with the X chromosome are members of gene families. Evolutionary considerations imply that genes on the Y chromosome will degenerate unless they have male advantageous or female deleterious functions. Spermatogenesis is an example of a male advantageous function and genes in three regions of the human Y chromosome have been promoted as candidate male fertility factors.  (+info)

Ancestral Asian source(s) of new world Y-chromosome founder haplotypes. (6/1444)

Haplotypes constructed from Y-chromosome markers were used to trace the origins of Native Americans. Our sample consisted of 2,198 males from 60 global populations, including 19 Native American and 15 indigenous North Asian groups. A set of 12 biallelic polymorphisms gave rise to 14 unique Y-chromosome haplotypes that were unevenly distributed among the populations. Combining multiallelic variation at two Y-linked microsatellites (DYS19 and DXYS156Y) with the unique haplotypes results in a total of 95 combination haplotypes. Contra previous findings based on Y- chromosome data, our new results suggest the possibility of more than one Native American paternal founder haplotype. We postulate that, of the nine unique haplotypes found in Native Americans, haplotypes 1C and 1F are the best candidates for major New World founder haplotypes, whereas haplotypes 1B, 1I, and 1U may either be founder haplotypes and/or have arrived in the New World via recent admixture. Two of the other four haplotypes (YAP+ haplotypes 4 and 5) are probably present because of post-Columbian admixture, whereas haplotype 1G may have originated in the New World, and the Old World source of the final New World haplotype (1D) remains unresolved. The contrasting distribution patterns of the two major candidate founder haplotypes in Asia and the New World, as well as the results of a nested cladistic analysis, suggest the possibility of more than one paternal migration from the general region of Lake Baikal to the Americas.  (+info)

Long-term fetal microchimerism in peripheral blood mononuclear cell subsets in healthy women and women with scleroderma. (7/1444)

Fetal CD34(+) CD38(+) cells have recently been found to persist in maternal peripheral blood for many years after pregnancy. CD34(+) CD38(+) cells are progenitor cells that can differentiate into mature immune-competent cells. We asked whether long-term fetal microchimerism occurs in T lymphocyte, B lymphocyte, monocyte, and natural-killer cell populations of previously pregnant women. We targeted women with sons and used polymerase chain reaction for a Y-chromosome-specific sequence to test DNA extracted from peripheral blood mononuclear cells (PBMC) and from CD3, CD19, CD14, and CD56/16 sorted subsets. We also asked whether persistent microchimerism might contribute to subsequent autoimmune disease in the mother and included women with the autoimmune disease scleroderma. Scleroderma has a peak incidence in women after childbearing years and has clinical similarities to chronic graft-versus-host disease that occurs after allogeneic hematopoietic stem-cell transplantation, known to involve chimerism. Sixty-eight parous women were studied for male DNA in PBMC and 20 for PBMC subsets. Microchimerism was found in PBMC from 33% (16 of 48) of healthy women and 60% (12 of 20) women with scleroderma, P =.046. Microchimerism was found in some women in CD3, CD19, CD14, and CD56/16 subsets including up to 38 years after pregnancy. Microchimerism in PBMC subsets was not appreciably more frequent in scleroderma patients than in healthy controls. Overall, microchimerism was found in CD3, CD19, and CD14 subsets in approximately one third of women and in CD56/16 in one half of women. HLA typing of mothers and sons indicated that HLA compatibility was not a requirement for persistent microchimerism in PBMC subsets. Fetal microchimerism in the face of HLA disparity implies that specific maternal immunoregulatory pathways exist that permit persistence but prevent effector function of these cells in normal women. Although microchimerism in PBMC was more frequent in women with scleroderma than healthy controls additional studies will be necessary to determine whether microchimerism plays a role in the pathogenesis of this or other autoimmune diseases.  (+info)

Preimplantation diagnosis by fluorescence in situ hybridization using 13-, 16-, 18-, 21-, 22-, X-, and Y-chromosome probes. (8/1444)

PURPOSE: Our purpose was to select the proper chromosomes for preimplantation diagnosis based on aneuploidy distribution in abortuses and to carry out a feasibility study of preimplantation diagnosis for embryos using multiple-probe fluorescence in situ hybridization (FISH) on the selected chromosomes of biopsied blastomeres. METHODS: After determining the frequency distribution of aneuploidy found in abortuses, seven chromosomes were selected for FISH probes. Blastomeres were obtained from 33 abnormal or excess embryos. The chromosome complements of both the biopsied blastomeres and the remaining sibling blastomeres in each embryo were determined by FISH and compared to evaluate their preimplantation diagnostic potential. RESULTS: Chromosomes (16, 22, X, Y) and (13, 18, 21) were selected on the basis of the high aneuploid prevalence in abortuses for the former group and the presence of trisomy in the newborn for the latter. Thirty-six (72%) of 50 blastomeres gave signals to permit a diagnosis. Diagnoses made from biopsied blastomeres were consistent with the diagnoses made from the remaining sibling blastomeres in 18 embryos. In only 2 of 20 cases did the biopsied blastomere diagnosis and the embryo diagnosis not match. CONCLUSIONS: If FISH of biopsied blastomere was successful, a preimplantation diagnosis could be made with 10% error. When a combination of chromosome-13, -16, -18, -21, -22, -X, and -Y probes was used, up to 65% of the embryos destined to be aborted could be detected.  (+info)

Anyone know of a RAT Y CHROMOSOME specific probe? Thanks in advance Abizar www.innogenex.com , -----Original Message----- , From: Angeline Martin-Studdard [mailto:[email protected]] , Sent: Monday, January 22, 2001 4:57 AM , To: [email protected] , Subject: mouse Y chromosome probe , , , Hi Dina, , , Ive been utilizing a mouse Y chromosome paint probe from Applied , Genetics (#BMPOY). I tested it on cell drop slides initially and , currently use it on paraffin embedded mouse brain tissue. Ive , only tested a few different fixation methods so far but hope to , make more progress with that in the near future. It works well , and Ive found I can get away with quite a bit less probe than , recommended. , , Let me know if you would like any more information. , Angeline , , Medical College of Georgia , Neurology , 1459 Laney-Walker Blvd , Augusta, GA 30912 , [email protected] , , , ,Date: 19 Jan 2001 15:21:31 -0600 , ,From: [email protected] , ,Subject: mouse Y chromosome ...
TY - JOUR. T1 - Human Y-chromosome-specific reiterated DNA. AU - Kunkel, Louis M.. AU - Smith, Kirby D.. AU - Boyer, Samuel H.. PY - 1976/1/1. Y1 - 1976/1/1. N2 - Radiolabeled reiterated DNA specific for the human Y chromosome has been obtained by extensive reassociations between [3H]DNA prepared from men and excess DNA from women. These highly purified labeled sequences reassociate only with DNA from individuals with a Y chromosome. The percentage of Y-chromosome-specific DNA isolated from individuals with differing numbers of Y chromosomes is a function of the number of Y chromosomes present. The purified Y-chromosome-specific sequences may represent between 7 and 11 percent of the human Y chromosome.. AB - Radiolabeled reiterated DNA specific for the human Y chromosome has been obtained by extensive reassociations between [3H]DNA prepared from men and excess DNA from women. These highly purified labeled sequences reassociate only with DNA from individuals with a Y chromosome. The percentage ...
Over the 180 My since their origin, the sex chromosomes of mammals have evolved a gene repertoire highly specialized for function in the male germline. The mouse Y chromosome is unique among mammalian Y chromosomes characterized to date in that it is large, gene-rich and euchromatic. Yet, little is …
Radiolabeled reiterated DNA specific for the human Y chromosome has been obtained by extensive reassociations between [3H]DNA prepared from men and excess DNA from women. These highly purifed labeled sequences reassociate only with DNA from individuals with a Y chromosome. The percentage of Y-chromosome-specific DNA isolated from individuals with differing numbers of Y chromosomes is a function of the number of chromosomes present. The purifed Y-chromosome-specific sequences may represent between 7 and 11 percent of the human Y chromosome. ...
Silene latifolia has heteromorphic sex chromosomes, the X and Y chromosomes. The Y chromosome, which is thought to carry the male determining gene, was isolated by UV laser microdissection and amplified by degenerate oligonucleotide-primed PCR. In situ chromosome suppression of the amplified Y chromosome DNA in the presence of female genomic DNA as a competitor showed that the microdissected Y chromosome DNA did not specifically hybridize to the Y chromosome, but hybridized to all chromosomes. This result suggests that the Y chromosome does not contain Y chromosome-enriched repetitive sequences. A repetitive sequence in the microdissected Y chromosome, RMY1, was isolated while screening repetitive sequences in the amplified Y chromosome. Part of the nucleotide sequence shared a similarity to that of X-43.1, which was isolated from microdissected X chromosomes. Since fluorescence in situ hybridization analysis with RMY1 demonstrated that RMY1 was localized at the ends of the chromosome, RMY1 may ...
The human Y chromosome is a male-specific sex chromosome. Nearly all humans who possess a Y chromosome will be morphologically male. Although the Y chromosome is situated in the cell nucleus, it only recombines with the X-chromosome at the ends of the Y chromosome; the vast majority of the Y chromosome (95%) does not recombine. When mutations (errors in the copying process) arise in the Y chromosome in the form of single-nucleotide polymorphisms) or short tandem repeats, they are passed down directly from father to son in a direct male line of descent. This line is known as the patriline. The Genome Reference Consortium maintains the reference assembly of the human genome. The GRC tracks issues relating to the Y chromosome such as gaps and errors in the sequence. Details can be found here. The GRCh37 build of the Y chromosome has a length of 59,373,566 base-pairs, but only 25,653,566 base-pairs are actually positioned. Build 38 (GRCh38) was released on 24 December 2013.[1] ...
Chimp and Human Y Chromosomes Evolving Faster Than Expected Wednesday, 13 January 2010 Contrary to a widely held scientific theory that the mammalian Y chromosome is slowly decaying or stagnating, new evidence suggests that in fact the Y is actually evolving quite rapidly through continuous, wholesale renovation. By conducting the first comprehensive interspecies comparison of Y chromosomes, Whitehead Institute researchers have found considerable differences in the genetic sequences of the human and chimpanzee Ys - an indication that these chromosomes have evolved more quickly than the rest of their respective genomes over the 6 million years since they emerged from a common ancestor. The findings are published online this week in the journal Nature. The region of the Y that is evolving the fastest is the part that plays a role in sperm production, say Jennifer Hughes, first author on the Nature paper and a postdoctoral researcher in Whitehead Institute Director David Pages lab. The rest of ...
Compared with the X chromosome, the mammalian Y chromosome is considerably diminished in size and has lost most of its ancestral genes during evolution. Interestingly, for the X-degenerate region on...
By one estimate, the human Y chromosome has lost 1,393 of its 1,438 original genes over the course of its existence, and linear extrapolation of this 1,393-gene loss over 300 million years gives a rate of genetic loss of 4.6 genes per million years.[21] Continued loss of genes at the rate of 4.6 genes per million years would result in a Y chromosome with no functional genes - that is the Y chromosome would lose complete function - within the next 10 million years, or half that time with the current age estimate of 160 million years.[16][22] Comparative genomic analysis reveals that many mammalian species are experiencing a similar loss of function in their heterozygous sex chromosome. Degeneration may simply be the fate of all non-recombining sex chromosomes, due to three common evolutionary forces: high mutation rate, inefficient selection, and genetic drift.[16] However, comparisons of the human and chimpanzee Y chromosomes (first published in 2005) show that the human Y chromosome has not ...
PLENARY PRESENTATION TUESDAY OCTOBER 19 2.00pm - 2.30pm SEQUENCE OF THE MOUSE Y CHROMOSOME Alfoldi JE1, Skaletsky H1, Graves T2, Minx P2, Wilson RK2, Rozen S1, Page DC1 1 Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, Cambridge, United States, 2 Genome Sequencing Center, Washington University School of Medicine, St. Louis, United States Y chromosomes have no partner with which to cross-over during meiosis, and so were once thought to be doomed to degeneration and gene loss. However, the recent discovery of palindromes on the human Y chromosome has given us hope of the continued survival of Y genes, since palindromes could be protecting their genes by gene conversion. The sequencing of the mouse Y chromosome was begun with the hope that it too has palindromes, and that these palindromes could be studied more easily in a more tractable organism. Now that some mouse Y sequence has been produced, we can see that this chromosome ...
Comparisons of Y-chromosome sequences in various mammals reveal abundant gene loss early in the chromosomes evolution but remarkable gene stability across the Y chromosomes of extant species. See Articles p.488 & p.494 Mammalian Y chromosomes, known for their roles in sex determination and male fertility, often contain repetitive sequences that make them harder to assemble than the rest of the genome. To counter this problem Henrik Kaessmann and colleagues have developed a new transcript assembly approach based on male-specific RNA/genomic sequencing data to explore Y evolution across 15 species representing all major mammalian lineages. They find evidence for two independent sex chromosome originations in mammals and one in birds. Their analysis of the Y/W gene repertoires suggests that although some genes evolved novel functions in sex determination/spermatogenesis as a result of temporal
Researcher(s): William J. Murphy, PhD Breed(s): All (non-specified). Abstract:. Studies of the human and mouse Y chromosomes have shown that they contain many testis specific genes that, when defective, cause infertility and spermatogenesis defects. The causes of male infertility in dogs are not well known. Though much is now known about genes on the dog autosomes and X chromosome, owing to the canine genome sequence, virtually nothing is known about the canine Y chromosome and the genes it harbors. This study will exhaustively characterize the gene content of the dog Y chromosome by sequencing from a cDNA selection library that is enriched for Y chromosome gene transcripts. This procedure will isolate the majority of canine Y chromosome genes and the DNA fragments they reside on, which will be mapped in the dog genome. The copy number and expression profile of these genes will be determined in a broad range of tissues to discern which genes have testis-specific expression patterns, and may ...
Among the many chromosomes in a mans body, the smallest one with the largest personality has to be the Y chromosome. With it, you are a male; without it, you are a female, with few exceptions. More than any other chromosome, it really defines who you are.. The Y chromosome controls other traits as well: hairy ears, tooth enamel, and stature to name a few. But for the longest time, the Y chromosome was also considered home to a lot of junk DNA that we thought had no purpose. We now know that much of this DNA has a purpose and that the Y is the home of many important male fertility genes.. Before its association with male fertility, the Y chromosome was widely considered a genetic black hole, a chromosome that evolved as a broken remnant of the X chromosome. We knew that the maleness gene was on the Y and a few other genes. However, since the Y chromosome has been fully undressed as a result of the human genome project, we now know that it is very unique, even special, and that it evolves in ...
A group of researchers from the University of California, Berkeley discovered that in mammals, males are XY and tend to live shorter lives than XX females. This is due to the Y chromosome as its genetic elements tend to jump around causing mutations. The Y chromosome densely packs DNA, called heterochromatin, keeps these elements in check. It is the heterochromatin when it deteriorates as organism age. This eventually plays a role in how long individuals live. As compared to females the heterochromatin in the genome stayed steady as compared to males this densely packed DNA was greatly reduced. The team, later on, created flies with abnormal numbers of Y chromosomes, and as a result, the females carrying the Y chromosomes and males with an extra Y did not live as long their wild types equivalents. Similar genetics elements were seen in these flies as in selfish, the males with no Y chromosome lived a lot longer than normal XY males. Drosophila aging is an attractive topic that is drawing many ...
Definition of Y chromosome in the Financial Dictionary - by Free online English dictionary and encyclopedia. What is Y chromosome? Meaning of Y chromosome as a finance term. What does Y chromosome mean in finance?
Y chromosomes control essential male functions in many species, including sex determination and fertility. However, because of obstacles posed by repeat-rich heterochromatin, knowledge of Y chromosome sequences is limited to a handful of model organisms, constraining our understanding of Y biology across the tree of life. Here, we leverage long single-molecule sequencing to determine the content and structure of the nonrecombining Y chromosome of the primary African malaria mosquito, Anopheles gambiae We find that the An. gambiae Y consists almost entirely of a few massively amplified, tandemly arrayed repeats, some of which can recombine with similar repeats on the X chromosome. Sex-specific genome resequencing in a recent species radiation, the An. gambiae complex, revealed rapid sequence turnover within An. gambiae and among species. Exploiting 52 sex-specific An. gambiae RNA-Seq datasets representing all developmental stages, we identified a small repertoire of Y-linked genes that lack X ...
The chromosome Y sequence has the pseudoautosomal regions (PAR) hard masked. This practice is consistent with the 1000 Genome Consortiums decision to hard mask these regions in chromosome Y in order to prevent mis-mapping of reads and issues in variant calling on the gender chromosomes.. The masked Y pseudoautosomal regions are chrY:10001-2649520 and chrY:59034050-59363566. (A related file can be downloaded from ftp://ftp.ensembl.org/pub/release-56/fasta/homo_sapiens/dna/Homo_sapiens.GRCh37.56.dna.chromosome.Y.fa.gz.). The following background information is from the UCSC site http://genome.ucsc.edu/cgi-bin/hgGateway?org=human&db=hg19 The Y chromosome in this assembly contains two pseudoautosomal regions (PARs) that were taken from the corresponding regions in the X chromosome and are exact duplicates:. chrY:10001-2649520 and chrY:59034050-59363566? chrX:60001-2699520 and chrX:154931044-155260560. ...
A Y chromosome represents about 2% of the human genome and is paternally inherited with low mutation rate. The Y chromosome STR test looks at the markers on a Y chromosome and compares them with other Y chromosome markers. Using this test we can determine paternal lineage of a male individual or determine the biological relationship between other male individuals. ...
History and description of Haplogroup T (Y-chromosomal DNA) and its subclades. Haplogroup T is an old Middle Eastern and East African lineage. It was found among ancient Babylonians, Phoenicians, Greeks and Romans.
Only males have a Y chromosome, which is always inherited from their father. There are very few genes on the Y chromosome, but a crucial gene involved in determining biological sex - SRY - is found on this chromosome and not the X chromosome. It is possible for individuals to only have a single X chromosome - these individuals are biologically female as they lack the Y chromosome and the SRY gene that determines biological maleness. It is not possible for individuals to only have a Y chromosome as the X chromosome is essential to life and development. ...
Male relatives can confirm their biological relationship by doing a Y chromosome test. The Y chromosome is only found in males and is a sex determining chromosome. If two males share the same Y chromosome it means that they also have the same paternal lineage. Testing the Y chromosome can be done for the following […]
An analysis of the genealogical and medical records of males in Utahs multi-generational families strongly supports the case that inherited variations in the Y chromosome, the male sex chromosome, play a role in the development of prostate cancer, according to a study presented on Friday, October 25, at the American Society of Human Genetics (ASHG) 2013 meeting in Boston. The study identified multiple, distinct Y chromosomes associated with a significant excess risk of prostate cancer, said Lisa Cannon-Albright, Ph.D., Professor and Chief of the Division of Genetic Epidemiology at the University of Utah School of Medicine. Dr. Cannon-Albright, who headed the study and presented the results, said that her lab plans to search these Y chromosomes for the genetic mutations that can predispose a man to develop prostate cancer, the second most frequently diagnosed cancer in the U.S. Because most of the Y chromosome does not recombine during cell division, it is passed virtually unchanged from father ...
In order to understand the intricacies of X and Y chromosome evolution, we investigate Y chromosome gene content and structure in our model marsupial, the tammar wallaby (Macropus eugenii ). Using gene-specific and whole Y chromosome probes to screen BAC libraries, we have identified novel genes on the wallaby Y.. Many of these genes are also conserved on the Y in other Australian (Tasmanian devil) and American (opossum) marsupials, but lost from the Y in placental mammals.. This project will focus on characterising genes on the Tasmanian Devil Y chromosome, not only helping to understand mammal Y chromosomes, but also the X.. ...
Despite this, recent research has shown that the Y chromosome has developed some pretty convincing mechanisms to put the brakes on, slowing the rate of gene loss to a possible standstill.. For example, a recent Danish study, published in PLoS Genetics, sequenced portions of the Y chromosome from 62 different men and found that it is prone to large scale structural rearrangements allowing gene amplification - the acquisition of multiple copies of genes that promote healthy sperm function and mitigate gene loss.. The study also showed that the Y chromosome has developed unusual structures called palindromes (DNA sequences that read the same forwards as backwards - like the word kayak), which protect it from further degradation. They recorded a high rate of gene conversion events within the palindromic sequences on the Y chromosome - this is basically a copy and paste process that allows damaged genes to be repaired using an undamaged back-up copy as a template.. Looking to other ...
YRRM1 - Y Chromosome RNA Recognition Motif. Looking for abbreviations of YRRM1? It is Y Chromosome RNA Recognition Motif. Y Chromosome RNA Recognition Motif listed as YRRM1
The human Y chromosome began to evolve from an autosome hundreds of millions of years ago, acquiring a sex-determining function and undergoing a series of inversions that suppressed crossing over with the X chromosome1, 2. Little is known about the recent evolution of the Y chromosome because only the human Y chromosome has been fully sequenced. Prevailing theories hold that Y chromosomes evolve by gene loss, the pace of which slows over time, eventually leading to a paucity of genes, and stasis3, 4. These theories have been buttressed by partial sequence data from newly emergent plant and animal Y chromosomes5, 6, 7, 8, but they have not been tested in older, highly evolved Y chromosomes such as that of humans. Here we finished sequencing of the male-specific region of the Y chromosome (MSY) in our closest living relative, the chimpanzee, chieving levels of accuracy and completion previously reached for the human MSY. By comparing the MSYs of the two species we show that they differ radically ...
We rarely use Wikipedia as a resource, but this overview on bone density is quite well done. As with any medical issue or question, please consult your physician. The Wikipedia entry is a general discussion of the topic. It is not specifically related to X and Y Chromosome Variations. For individuals who are 47,XXY, untreated hypogonadism can lead to osteoporosis and osteopenia. Most benefit from testosterone replacement therapy (TRT). Those who identify as intersex or choose not to use TRT should seek competent medical help for alternative methods to preserve bone density.. Read more ...
Genetic conflicts between sexes and generations provide a foundation for understanding the functional evolution of sex chromosomes and sexually dimorphic phenotypes. Y chromosomes of Drosophila contain multi-megabase stretches of satellite DNA repeats and a handful of protein-coding genes that are monomorphic within species. Nevertheless, polymorphic variation in heterochromatic Y chromosomes of Drosophila result in genome-wide gene expression variation. Here we show that such naturally occurring Y-linked regulatory variation (YRV) can be detected in somatic tissues and contributes to the epigenetic balance of heterochromatin/euchromatin at three distinct loci showing position-effect variegation (PEV). Moreover, polymorphic Y chromosomes differentially affect the expression of thousands of genes in XXY female genotypes in which Y-linked protein-coding genes are not transcribed. The data show a disproportionate influence of YRV on the variable expression of genes whose protein products localize ...
Scientists in the US have published the results of their detailed scrutiny of the genetic sequence of the human Y chromosome. This DNA bundle - one of 24 distinct chromosomes found in human cells - holds the crucial information to make the male of our species. The work is part of the enormous job of following up the data that came out of the international Human Genome Project (HGP)…declared complete in April. Any attempt to make sense of the data inevitably involves large-scale computing effort, but, by any standards, annotating the Y chromosome was a huge task. Its one thing to generate the sequence and its another to go on to discover which bits are functional and what they can tell us about disease and evolution, explained Mark Ross, head of the Wellcome Trust Sanger Institutes project to analyse the X chromosome near Cambridge, UK. The Y chromosome contains a great many repeated sections of DNA and far fewer genes, letter for letter, than other chromosomes. Francis Collins, director of ...
Health,...Countering common belief study shows rapid genetic change in both hum...WEDNESDAY Jan. 13 (HealthDay News) -- The Y chromosome found only in...The new study challenges the widely held belief that the mammalian Y c...The Y chromosome is present in males (who have one Y and one X chromos...,Males,Y,Chromosome,Not,in,Decline,medicine,medical news today,latest medical news,medical newsletters,current medical news,latest medicine news
Basically, a fertilized egg can contain a modified Y chromosome that is itself a palindrome, Page said. That modified or isodicentric Y chromosome is so unpredictably stable or unstable that individuals who develop from such a fertilized egg range from a man with no sperm who is otherwise healthy to someone raised as a boy who is later found to have an ovary on one side to a girl or woman with Turner syndrome. These wildly different outcomes result from the very same starting point.. The key to an isodicentric Y chromosomes instability is its two centromeres, Page explained. Centromeres are critical for the proper segregation of chromosomes into two daughter cells at each cell division. If there are two centromeres, the apparatus for partitioning chromosomes becomes very confused, he said. A chromosome can get tugged in two directions at once. As a result, the chromosome has a tendency to get broken or lost each time cells divide. During the development of an embryo, cells divide ...
A toothpick and a bit of chance shaped David Page’s career, which he has dedicated to understanding the mammalian Y chromosome and fetal germ cell development.
A toothpick and a bit of chance shaped David Pages career, which he has dedicated to understanding the mammalian Y chromosome and fetal germ cell development.. 0 Comments. ...
In this study we have established a simple, accurate and widely applicable method for determining the sex of primate DNA samples by using triple primer PCR of a small region of the UTX/UTY gene. The ubiquitously transcribed tetratricopeptide repeat protein gene (UTX/UTY) is located on the X and Y chromosomes and our analysis identified a region in the human UTY having the highest identity to the mouse Y chromosome. Due to the high conservation of this region the triple primer PCR setup works in all primate species tested. Furthermore, the method contains an internal positive control (the shared primer), but should always be tested in samples of known sex before actual analysis is carried out. Also, it may be necessary to perform species specific optimization of annealing temperature and/or primer concentrations prior to analysis. Since the nature of the Y chromosome allows deletion of many regions, it can be expected that with an increased number of individuals tested deletion of UTY might be ...
Inferring chimpanzee Y chromosome history and amplicon diversity from whole genome sequencing Matthew Oetjens, Feichen Shen, Zhengting Zou, Jeffrey Kidd bioRxiv doi: http://dx.doi.org/10.1101/029702 Due to the lack of recombination, the male-specific region of the Y chromosome (MSY) is a unique resource for tracking the genetic history of populations. The MSY is also enriched for large,…
Classically, Y chromosomes are thought to originate from X chromosomes through a process of degeneration and gene loss. Now, the availability of 12 Drosophila genomes provides an opportunity to study the origin and evolution of Y chromosomes in an informative phylogenetic context. Surprisingly, the …
A few dozen genes are known on the human Y chromosome. The completion of the human genome sequence will allow identification of the remaining loci, which should shed further light on the function and evolution of this peculiar chromosome.
(Phys.org) -University of Arizona geneticists have discovered the oldest known genetic branch of the human Y chromosome - the hereditary factor determining male sex.
The Y chromosome is ane o twa sex chromosomes (allosomes) in mammals, includin humans, an mony ither ainimals. The ither is the X chromosome. Y is the sex-determinin chromosome in mony species, syne it is the presence or absence o Y that determines the male or female sex o offspring produced in sexual reproduction. In mammals, the Y chromosome contains the gene SRY, which causes testis development. ...
The evolution of human populations has long been studied with unique sequences from the nonrecombining, male-specific Y chromosome (see the Perspective by Cann). Poznik et al. (p. 562) examined 9.9 Mb of the Y chromosome from 69 men from nine globally divergent populations-identifying population and individual specific sequence variants that elucidate the evolution of the Y chromosome. Sequencing of maternally inherited mitochondrial DNA allowed comparison between the relative rates of evolution, which suggested that the coalescence, or origin, of the human Y chromosome and mitochondria both occurred approximately 120 thousand years ago. Francalacci et al. (p. 565) investigated the sequence divergence of 1204 Y chromosomes that were sampled within the isolated and genetically informative Sardinian population. The sequence analyses, along with archaeological records, were used to calibrate and increase the resolution of the human phylogenetic tree. ...
This idea is based on evaluations of modern X and Y sex chromosomes that evolutionists think resulted from an original common ancestral pair of identical chromosomes. They speculate that over long ages genes have been lost from the Y chromosome in humans and other mammals….[but] essential Y genes are rescued by relocating to other chromosomes.3 This conclusion was largely based on a study by Jennifer Hughes and her team.The study used the assumption that the mammalian X and Y chromosomes evolved from a single pair of autosomes [non-sex chromosomes].4. A problem is, even assuming evolution occurred, we have no knowledge of the common ancestor of mammals, although several candidates have been proposed. One of the more recent is a tiny, furry-tailed creature that evolved shortly after the dinosaurs disappeared.5 This 2013 conclusion was considered so radical that some mammalian experts called for a reevaluation of the evolutionary story of placental mammals.5 If we cannot decide which ...
Chromosome Y: Genes, Leukemias, Solid Tumors, and Cancer-Prone Diseases located on Chromosome Y reviewed and published in the Atlas of Genetics and Cytogenetics in Oncology and Haematology
The most prominent clade in Taiwan, O-M175 as a whole, represents almost 90% of Y chromosomes among the TwHan, about 95% among the TwPlt and more than 99% among the TwMtA (Additional file 1: Figures S1 and S2). Only one representative of the basal O*/O1*-M175 (xM119, P31, M122) was seen in each of the Luzon (Philippines), Fujian and TwPlt samples (Figure 2 and Additional file 1: Table S2). All other haplogroups of the O clade were observed at the derived state for the M119, P31 and M122 markers (Figure 2, Additional file 1: Table S2, and Additional file 1: Figures S1 and S2).. Haplogroup O1a*-M119 (Figure 2 and Additional file 1: Table S2) is seen throughout Batan (42%), the Philippines (4% to 33%) and Indonesia (4% to 18%). It has a patchy distribution among TwMtA (3-33%) and only some southern TwMtA show frequencies greater than 10% (i.e. Puyuma, Paiwan and Yami). O1a*-M119 was not observed in our Amis sample, neither in the Bunun, Saisiyat and Thao and has a low frequency among TwHan (1.4% to ...
EasyDNA Australia offers Y chromosome testing. The Y Chromosome test is used to determine if males share the same paternal lineage. Order your DNA test today!
In Genome Research this week: Y chromosome gene expression analysis, de novo mutations rise with paternal age in rhesus macaques, and more.
New light is being shed on a little-known role of Y chromosome genes, specific to males, that could explain why men suffer differently than women from various diseases, including COVID-19.
For many years it was believed that recombination on the human Y chromosome was restricted to the XY-homologous pseudoautosomal regions, with over 95% of the Y chromosome believed to be non-recombining. Over the past 7 years gene conversion has been shown to occur between several classes of paralog situated outside of the pseudoautosomal regions. Gene conversion has been shown to occur both intrachromosomally on the Y chromosome, and between the X and the Y chromosomes (Cruciani et al. 2010; Rosser et al. 2009; Rozen et al. 2003; Trombetta et al. 2009) and several biases in the direction of gene conversion have been suggested (Bosch et al. 2004; Rozen et al. 2003; Trombetta et al. 2009). This study has used interspecies sequence comparisons to identify regions of the Y chromosome which are likely to be undergoing gene conversion. Phylogenetic analysis of paralogous sequence variants (PSVs) or gametologous sequence variants (GSVs) identified between these regions has been carried out. ...
TUCSON, ARIZONA-Geneticists from the University of Arizona have identified an extremely rare Y chromosome that they say is the oldest-known branch of the human Y chromosome lineage tree. The discovery pushes back the most recent common ancestor for the lineage tree to 338,000 years ago, before the appearance of modern humans in the fossil record. This particular Y chromosome came from an African-American man living in South Carolina who had sent a DNA sample to a consumer genetic testing company. His Y chromosome was eventually matched with 11 men from western Cameroon. And the sequences of those individuals are variable, so its not like they all descended from the same grandfather, said Michael Hammer of the University of Arizona. It is likely that other divergent lineages will be found, whether in Africa or among African-Americans in the U.S. and that some of these may further increase the age of the Y chromosome tree, he added. ...
Previous studies of Y chromosome variation have revealed that western Europe, the Volga-Ural region, and the Caucasus differ dramatically with respect to Y-SNP haplogroup composition. The European part of Russia is situated in between these three regions; to determine if these differences reflect clines or boundaries in the Y-chromosome landscape, we analyzed 12 Y-SNPs in 545 males from 12 populations from the European part of Russia. The majority of Russian Y chromosomes (from 74% to 94%) belong to three Y chromosomal lineages [I-M170, R1a1-M17, and N3-TAT] that are also frequent in the rest of east Europe, north Europe, and/or in the Volga-Ural region. We find significant but low correlations between haplogroup frequencies and the geographic location of populations, suggesting gradual change in the Y chromosome gene pool across western Eurasia. However, we also find some significant boundaries between populations, suggesting that both isolation and migration have influenced the Y chromosome ...
Approach and Results-A total of 1988 biologically unrelated men from 4 white European populations were genotyped using 11 Y chromosome single nucleotide polymorphisms and classified into 13 most common European haplogroups. Approximately 75% to 93% of the haplotypic variation of the Y chromosome in all cohorts was attributable to I, R1a, and R1b1b2 lineages. None of traditional cardiovascular risk factors, including body mass index, blood pressures, lipids, glucose, C-reactive protein, creatinine, and insulin resistance, was associated with haplogroup I of the Y chromosome in the joint inverse variance meta-analysis. Fourteen of 15 ubiquitous single-copy genes of the male-specific region were expressed in human macrophages. When compared with men with other haplogroups, carriers of haplogroup I had ≈0.61- and 0.64-fold lower expression of ubiquitously transcribed tetratricopeptide repeat, Y-linked gene (UTY) and protein kinase, Y-linked, pseudogene (PRKY) in macrophages (P=0.0001 and P=0.002, ...
Y chromosome haplotyping based on microsatellites and single nucleotide polymorphisms (SNPs) has proved to be a powerful tool for population genetic studies of humans. However, the promise of the approach is hampered in the majority of nonhuman mammals by the lack of Y-specific polymorphic markers. We were able to identify new male-specific polymorphisms in the domestic cat Felis catus and 6 additional Felidae species with a combination of molecular genetic and cytogenetic approaches including 1) identifying domestic cat male-specific microsatellites from markers generated from a male cat microsatellite-enriched genomic library, a flow-sorted Y cosmid library, or a Y-specific cat bacteria artificial chromosome (BAC) clone, (2) constructing microsatellite-enriched libraries from flow-sorted Y chromosomes isolated directly from focal wildcat species, and (3) screening Y chromosome conserved anchored tagged sequences primers in Felidae species. Forty-one male-specific microsatellites were ...
Looking for online definition of pseudoautosomal region in the Medical Dictionary? pseudoautosomal region explanation free. What is pseudoautosomal region? Meaning of pseudoautosomal region medical term. What does pseudoautosomal region mean?
The evolution of sex chromosome dimorphism (SCD) is generally thought to follow a repeatable pattern. If one of the sex chromosomes carries a sex-determining region with at least two loci that should be linked together, selection favours the process of preventing sex chromosomes from recombination [1,2]. In turn, the lack of recombination leads to degeneration of the chromosome that is present only in one sex. The genetic degeneration of the hemizygous chromosome can occur because of Hill-Robertson effects, such as Mullers ratchet, background selection and the hitchhiking of deleterious alleles to advantageous mutations (reviewed in Charlesworth & Charlesworth [3]). Genetic degeneration, accompanied by morphological shrinking of hemizygous chromosomes, is observed in both XY and ZW chromosome systems [2,4]. Yet, most of the research focus has been on the mammalian Y chromosome [5], in which rapid degeneration can, to some extent, be attributed to a higher mutation rate in males (owing to more ...
The most common variations involve a trisomy, which means three sex chromosomes instead of the typical two. Girls who are born with an extra X chromosome are referred to as having Triple X or Trisomy X. Boys who are born with an extra X chromosome have 47,XXY, also known as Klinefelter syndrome. And boys who are born with an extra Y chromosome have 47,XYY, occasionally referred to as Jacobs syndrome. In addition, there are a number of other X and/or Y conditions including 48 or 49 chromosomes. These include 48,XXXX, 48XXXY, 48XXYY and 48XYYY; and although increasingly rare, also 49XXXXX, 49XXXXY, 49XXXYY, 49XXYYY and 49XYYY. Some individuals may have two cell lines, which is called mosaicism, such as 46,XY/47,XXY.. ...
Background: Array CGH is a powerful tool for the detection of copy number changes in the genome. Methods: We have developed a human X and Y chromosome tiling path array for the analysis of sex chromosome aberrations. Results: Normal X and Y chromosome profiles were established by analysis with DNA from normal fertile male and female individuals. Infertile males with known Y deletions confirmed the competence of the array to detect AZFa, AZFb and AZFc deletions and to distinguish between different AZFc lesions. Examples of terminal and interstitial deletions of Xp (previously characterised through cytogenetic and microsatellite analysis - [Lachlan et al, 2006]) have been assessed on the arrays both confirming and refining the established deletion breakpoints. Breakpoints in iso-Yq, iso-Yp and X-Y translocation chromosomes and X-Y interchanges in XX males are also amenable to analysis. Discussion: The resolution of the tiling path clone set used allows breakpoints to be placed within 100-200Kb, ...
This review considers genome-scale evidence on ancient Y chromosome diversity that has recently started to accumulate in geographic areas favourable to DNA preservation.
The Y chromosome data seems particularly exciting (there is a spreadsheet of populations in the download directory). One of the weaknesses of the 1000 Genomes data was that it didnt have any populations between Tuscany and East/South Asia, and the new dataset seems to rectify that ...
Haplogroup E, defined by mutation M40, is the most common human Y chromosome clade within Africa. To increase the level of resolution of haplogroup E, we disclosed the phylogenetic relationships among 729 mutations found in 33 haplogroup DE Y-chromosomes sequenced at high coverage in previous studies. Additionally, we dissected the E-M35 subclade by genotyping 62 informative markers in 5,222 samples from 118 worldwide populations. The phylogeny of haplogroup E showed novel features compared with the previous topology, including a new basal dichotomy. Within haplogroup E-M35, we resolved all the previously known polytomies and assigned all the E-M35* chromosomes to five new different clades, all belonging to a newly identified subhaplogroup (E-V1515), which accounts for almost half of the E-M35 chromosomes from the Horn of Africa. Moreover, using a Bayesian phylogeographic analysis and a single nucleotide polymorphism-based approach we localized and dated the origin of this new lineage in the ...
Writing in PLoS Genetics, Makova explains that by comparing the DNA of the X and Y chromosomes in eutherian mammals to the DNA of the non-sex chromosomes in the opossum and platypus, the researchers were able to go back in time to the point when the X and Y chromosomes were still swapping DNA, just like the non-sex chromosomes in the opossum and platypus. The scientists then were able to observe how the DNA of the X and Y chromosomes changed over time relative to the DNA of the non-sex chromosomes. Our research revealed that the Y-specific DNA began to evolve rapidly at the time that the DNA region split into two entities, while the X-specific DNA maintained the same evolutionary rate as the non-sex chromosomes, said Makova.. After determining that the Y chromosome has been evolving more rapidly and has been losing more genes as a result, they wanted to find out why the Y chromosome has not already disappeared entirely. Today, the human Y chromosome contains less than 200 genes, while the ...
TY - CHAP. T1 - Mammalian Sex Chromosomes Evolution in Cooper d.N.. AU - Dorus, S. AU - Wyckoff, J. AU - Lahn, B T. PY - 2003. Y1 - 2003. M3 - Chapter. VL - 3. SP - 822. EP - 826. BT - Nature Encyclopedia of the Human Genome. ER - ...
Does it change any of my conclusions in my chimp genome paper (sadly enough, the most popular thing Ive ever written)? Not really. On the one hand, this is yet another example of a part of the human genome that really does significantly differ from the chimp genome. I documented some of those in the article, including the size difference in the Y chromosomes. I concluded that these differences are quite minor features that are overwhelmed by the near-identity of the rest of the human and chimp genomes. In the case of the MSY, its important to keep in mind that the chimp MSY sequence reported by Hughes et al. is only 25.8 Mb. Thats slightly less than 1% of the entire genome. Given that fixed nucleotide differences between the human and chimp genomes are around 1%, having yet another 1% difference in the very different Y chromosomes doesnt make the genomes that much more different than they already were ...
The discovery and UA analysis of an extremely rare African American Y chromosome push back the time of the most recent common ancestor for the Y chromosome lineage tree to 338,000 years ago. This time predates the age of the oldest known anatomically modern human fossils.
What I was referring to was the possibility that the Y chromosome, in whole or in part, can recombine with the X chromosome and thus leave a trace in a genetic and physiological female. Without the key gene structure (SRY) that determines masculine development, an individual that is genetically male can develop as a female (and vice versa should SRY be recombined into an X chromosome). However, the likelihood of any of this occuring in nature is sustantially reduced as approximately 95% of the Y chromosome has been rendered incapable of recombination. Basically, a few small regions near the end of a Y chromosome are capable of recombining with an X chromosome but they are far away from any of the sex-determining regions. It is thus possible for a daughter to have some recombined Y chromosome DNA from their father, but not really anything deterministic for their physiological development. There are possible physical errors that can occur during meiosis (cell division producing reproductive ...
What I was referring to was the possibility that the Y chromosome, in whole or in part, can recombine with the X chromosome and thus leave a trace in a genetic and physiological female. Without the key gene structure (SRY) that determines masculine development, an individual that is genetically male can develop as a female (and vice versa should SRY be recombined into an X chromosome). However, the likelihood of any of this occuring in nature is sustantially reduced as approximately 95% of the Y chromosome has been rendered incapable of recombination. Basically, a few small regions near the end of a Y chromosome are capable of recombining with an X chromosome but they are far away from any of the sex-determining regions. It is thus possible for a daughter to have some recombined Y chromosome DNA from their father, but not really anything deterministic for their physiological development. There are possible physical errors that can occur during meiosis (cell division producing reproductive ...
Morphologically then X that is functionally distinct and chromosomes need over repeatedly developed over the tree out of lives. But that the level out of differentiation amongst the intercourse chromosomes differs considerably around types. The Y chromosome gene activity decays, leaving genes on the sex chromosomes reduced to a single functional copy in males as sex chromosomes diverge. Mechanisms own evolved to pay with this decrease in gene dosage. Right right Here, people execute a comparative review concerning intercourse chromosome techniques all-around poeciliid types plus unearth overwhelming variation as part of their education concerning sex chromosome differentiation to Y chromosome degeneration. Also, people come across proof for a full situation concerning chromosome-wide dosage payment at seafood. Your results need crucial ramifications towards intercourse chromosome development plus legislation. After recombination try halted between your X and also Y chromosomes, sex chromosomes ...
Charlesworth and Charlesworth 1997) seems to approximate the simulations reasonably well for a small equilibrium size of the best class (although this is highly dependent on the mutation rate), but greatly overestimates the time for a click when n0 is large or u is low.. The observation that, for a constant n0 and constant s, we did not observe significant differences in the speed of the ratchet, over an order of magnitude change in the population size (Figure 1), suggests that n0s is an important parameter, although the expression for the average time between clicks of the ratchet is not an explicit function of n0s. For the parameter range considered here we observe that an increase of 10-fold in n0s caused a decrease of ~10-fold in the speed of the ratchet.. Y and neo-Y chromosome degeneration: Because an incipient Y chromosome, or a neo-Y chromosome resulting from an autosome fusion or translocation, that fails to recombine with its homologue in the heterogametic sex is vulnerable to the ...
The Dniester-Carpathian region has attracted much attention from historians, linguists, and anthropologists, but remains insufficiently studied genetically. We have analyzed a set of autosomal polymorphic loci and Y-chromosome markers in six autochthonous Dniester-Carpathian population groups: 2 Moldavian, 1 Romanian, 1 Ukrainian and 2 Gagauz populations. To gain insight into the population history of the region, the data obtained in this study were compared with corresponding data for other populations of Western Eurasia. The analysis of 12 Alu human-specific polymorphisms in 513 individuals from the Dniester-Carpathian region showed a high degree of homogeneity among Dniester-Carpathian as well as southeastern European populations. The observed homogeneity suggests either a common ancestry of all southeastern European populations or a strong gene flow between them. Nevertheless, tree reconstruction and principle component analyses allow the distinction between Balkan-Carpathian (Macedonians, ...
We analyzed the AZFc region of the Y-chromosome for complete (b2/b4) and distinct partial deletions (gr/gr, b1/b3, b2/b3) in 822 infertile and 225 proven fertile men. We observed complete AZFc deletions in 0.97% and partial deletions in 6.20% of the cases. Among partial deletions, .... ...
Research published in this weeks Science reveals that the Y chromosome developed from an X-like ancestor around 300 million years ago.. Of our 46 human chromosomes, 44 form matched pairs. But two - the X and the Y chromosomes - stand apart because they have no perfect match. But it wasnt always like this. Researchers at the Howard Hughes Medical Institute have found that the X and Y chromosomes evolved from a standard identical pair around 300 million years ago - shortly after the divergence of the evolutionary lines leading to mammals and birds.. The first events that created the sex chromosomes had been thought to have occurred at least 170 million years ago, says researcher Dr David Page. Were pushing that back another 100 million years or so.. Page and colleague Dr Bruce Lahn reconstructed the stages of sex chromosome evolution, and the time course over which these chromosomes were built. By fossil digging on the sex chromosomes, we were able to reconstruct the four events that drove ...
It was hosted by the National Human Genome Research Institute (NHGRI), and featured several prominent scientists. I was only able to attend one of the sessions, that given by one of the rockstars in my field, David Page, M.D.. I tweeted about the talk (I missed a few bits here and there due to glitches with the live broadcast, but caught most of it), but didnt think to look up the hashtag (I had to run to make it on time after pumping). To summarize, the first half of the talk was a summary of sex chromosome evolution, focusing particularly on the Y chromosome. The second half discussed new research connecting the Y chromosome with infertility and (the really exciting part), potentially Turner Syndrome. He finished by emphasizing that careful, complete sequencing is necessary for studies of the Y chromosome, and for understanding the impact of both the Y chromosome and complex regions of the genome on human disease and infertility ...
In the framework of the project Immigration and mobility in mediaeval and post-mediaeval Norway molecular genetic analyses were performed on 97 pre-modern human remains including genetic sexing and Y-chromosomal DNA typing. All samples were subjected to molecular genetic analyses of the sex using Genderplex consisting of two diff erent regions of the amelogenin gene, SRY and four X-STR loci. From 90% of the extracted remains (n=87) sex assignment was possible. Of these, 49 (56.3%) brought a genetically male result. All of these DNA extracts were subjected to Y-STR analysis using Yfiler Plus PCR Amplification Kit (Thermo Fisher Scientifi c) and/or PowerPlex Y23 System (Promega). At least partial Y-STR profiles were obtained from all samples. A detailed comparison between mediaeval/post-mediaeval and contemporary Y-chromosomes was performed by searching the obtained haplotypes (HTs) in the Y Chromosome Haplotype Reference Database (YHRD: https://yhrd.org) comprising 154,329 haplotypes from 991 ...
Repeated elements are remarkably important for male meiosis and spermiogenesis in Drosophila melanogaster. Pairing of the X and Y chromosomes is mediated by the ribosomal RNA genes of the Y chromosome and X chromosome heterochromatin, spermiogenesis depends on the fertility factors of the Y chromosome. Intriguingly, a peculiar genetic system of interaction between the Y-linked crystal locus and the X-linked Stellate elements seem to be also involved in male meiosis and spermiogenesis. Deletion of the crystal element of the Y, via an interaction with the Stellate elements of the X, causes meiotic abnormalities, gamete-genotype dependent failure of sperm development (meiotic drive), and deposition of protein crystals in spermatocytes. The current hypothesis is that the meiotic abnormalities observed in cry- males is due to an induced overexpression of the normally repressed Ste elements. An implication of this hypothesis is that the strength of the abnormalities would depend on the amount of the ...
The Infertility Center of St. Louis was the first to study the relationship between the Y chromosome and male infertility. Tiny amounts of sperm are often found in the testes of azoospermic men previously thought to be making no sperm. Read more to learn what Dr. Silbers research means for you.
We have characterized the Y chromosome carried by President Thomas Jefferson, the general rarity of which supported the idea that he, or a patrilineal relative, fathered the last son of his slave Sally Hemings. It belongs to haplogroup K2, a lineage representing only approximately 1% of chromosomes worldwide, and most common in East Africa and the Middle East. Phylogenetic network analysis of its Y-STR (short tandem repeat) haplotype shows that it is most closely related to an Egyptian K2 haplotype, but the presence of scattered and diverse European haplotypes within the network is nonetheless consistent with Jeffersons patrilineage belonging to an ancient and rare indigenous European type. This is supported by the observation that two of 85 unrelated British men sharing the surname Jefferson also share the Presidents Y-STR haplotype within haplogroup K2. Our findings represent a cautionary tale in showing the difficulty of assigning individual ancestry based on a Y-chromosome haplotype, ...
The pseudoautosomal (PA) region of the mammalian genome is the region of the X and Y chromosomes that shares extensive DNA sequence homology and is of special interest because it may play an essential role during male meiosis. We have identified three telomere-related restriction fragments from the PA region of the mouse genome, using an oligonucleotide probe composed of the mammalian telomere consensus sequence TTAGGG. PA assignment of two C57BL/6J-derived fragments was initially suggested by analysis of DNAs from progeny sired by C57BL/6J males carrying the rearranged Y chromosome, Y*: the hybridization intensity of both fragments was concordant with the sex-chromosome complement of the offspring. Further analysis indicated that both fragments were present in female and male F1, mice regardless of the sex of their C57BL/6J parent--a criterion for autosomal or PA linkage. Both fragments were closely linked to each other and located on the X chromosome distal to amelogenin (Amg)--in
Submitted on 19 Dec 2014) House of Aisin Gioro is the imperial family of the last dynasty in Chinese history - Qing Dynasty (1644 - 1911). Aisin Gioro family originated from Jurchen tribes and developed the Manchu people before they conquered China. By investigating the Y chromosomal short tandem repeats (STRs) of 7 modern male individuals who claim belonging to Aisin Gioro family (in which 3 have full records of pedigree), we found that 3 of them (in which 2 keep full pedigree, whose most recent common ancestor is Nurgaci) shows very close relationship (1 - 2 steps of difference in 17 STR) and the haplotype is rare. We therefore conclude that this haplotype is the Y chromosome of the House of Aisin Gioro. Further tests of single nucleotide polymorphisms (SNPs) indicates that they belong to Haplogroup C3b2b1*-M401(xF5483), although their Y-STR results are distant to the star cluster, which also belongs to the same haplogroup. This study forms the base for the pedigree research of the imperial ...
Disclaimer: This site is for educational purposes only; it can not be used in diagnosis or treatment. Cite this page: Cotterill SJ. Chromosome Y, Cancer Genetics Web: http://www.cancerindex.org/geneweb/clinkc24.htm Accessed: [Home] Page last revised: 15 February, 2015 © Copyright 1999-. ...
The Y chromosome may be a symbol of masculinity, but it is becoming increasingly clear that it is anything but strong and enduring. Although it carries the
It is generally well known that men have an overall shorter life expectancy compared to women. A recent study, led by Uppsala University researchers, shows a correlation between a loss of the Y chromosome in blood cells and ...
Modern humans diverged from Neanderthals some 600,000 years ago - and a new study shows the Y chromosome might be what kept the two species separate. It seems we were genetically incompatible with our ancient relatives - and male fetuses conceived through sex with Neanderthal males would have miscarried. We knew that some cross-breeding between…
In genetic sex-determination systems, an organisms sex is determined by the genome it inherits. Genetic sex-determination usually depends on asymmetrically inherited sex chromosomes which carry genetic features that influence development; sex may be determined either by the presence of a sex chromosome or by how many the organism has. Genetic sex-determination, because it is determined by chromosome assortment, usually results in a 1:1 ratio of male and female offspring. Humans and other mammals have an XY sex-determination system: the Y chromosome carries factors responsible for triggering male development. The default sex, in the absence of a Y chromosome, is female. Thus, XX mammals are female and XY are male. XY sex determination is found in other organisms, including the common fruit fly and some plants. In some cases, including in the fruit fly, it is the number of X chromosomes that determines sex rather than the presence of a Y chromosome (see below). In birds, which have a ZW ...
Genghis Khan achievements: If you ever had any doubts about a single man making any notable difference in the world, Genghis Khans genetic legacy will dispel them. He not only carved himself an immense empire, he contributed to populating it himself. He has over 16 million descendants presently thriving in parts of the former Mongol Empire. Science is finding out more about the history of Genghis Khan and his legacy through studies of the Y chromosome.
The minimum requirements for a Y chromosome with Monika Ward; Eliot Marshall checks in on U.S.s missile interception program 30 years later; Sylvia Zhu breaks down observations from the brightest gamma-ray burst.. ...
have scientests found any disorders that are linked to the y chromosome? If they have could you tell me where I can get more info on it, cause last I heard they havnt ...
Forensic Sci Int. 2002 Jan 24;125(1):86-9. Related Articles, Links Y-chromosome STR haplotypes in a southwest Spain population sample. Gamero JJ, Romero JL, Gonzalez JL, Carvalho M, Anjos MJ, Real FC, Vide MC. Department of Legal Medicine, Faculty of Medicine, University of Cadiz, Fragela s/n, Cadiz 11003, Spain. [email protected] The Y-chromosome polymorphism of eight STRs (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392; DYS393, DYS385) were studied in 111 unrelated
The male sex chromosome has long been called our genetic junkyard, a clutter of meaningless DNA surrounding a handful of genes--and those only good for making more men. But after rummaging through the scrap heap, two biologists say they have discovered five genes that are used throughout the body to help keep cells working properly. The researchers also describe in todays issue of Science another seven genes that are unique to the Y chromosome and lie in regions known to be involved in infertility.. Massachusetts Institute of Technology biologists Bruce Lahn and David Page knew that the Y chromosomes barren reputation rested on limited evidence. Panning for gold, the researchers examined cells from human testes, where they guessed genes on the Y chromosome should be particularly active. They collected messenger RNA (mRNA), which is made from active genes and eventually codes for proteins; because each gene has a unique corresponding mRNA strand, mRNA levels reveal which genes are actively ...
Chromosome condensation[edit]. Phosphorylation of H3 at serine 10 (phospho-H3S10). The mitotic kinase aurora B phosphorylates ... Rizzo PJ (Aug 2003). "Those amazing dinoflagellate chromosomes". Cell Research. 13 (4): 215-7. doi:10.1038/sj.cr.7290166. PMID ... Without histones, the unwound DNA in chromosomes would be very long (a length to width ratio of more than 10 million to 1 in ... When the diploid cells are duplicated and condensed during mitosis, the result is about 120 micrometers of chromosomes.[3] ...
a b c The Y Chromosome Consortium 2008 *^ a b c d e f g Cristofaro; et al. (2013). "Afghan Hindu Kush: Where Eurasian Sub- ... The Y Chromosome Consortium tree[edit]. This is the 2008 tree produced by the Y Chromosome Consortium (YCC).[13] Subsequent ... a b c d T. M. Karafet, 'High Levels of Y-Chromosome Differentiation among Native Siberian Populations and the Genetic Signature ... a b c David K. Faux, 2007, The Genetic Link of the Viking - Era Norse to Central Asia: An Assessment of the Y Chromosome DNA, ...
Y-chromosome DNA[edit]. Y-Dna haplogroups, passed on exclusively through the paternal line, were found at the following ... "Y chromosomes and mtDNA of Tuareg nomads from the African Sahel". European Journal of Human Genetics. 18 (8): 915-923. doi ... "Phylogeographic analysis of haplogroup E3b (E-M215) y chromosomes reveals multiple migratory events within and out of Africa" ...
Listed here are the human Y-chromosome DNA haplogroups in Arabia (Yemen,[18] Oman,[19] Qatar,[20] Kuwait,[21] Saudi Arabia[22] ... Y-chromosome haplogroup frequencies (%) in the studied populations. doi:10.1371/journal.pone.0056775.s006 (XLS) ... Haplogroup J is the most abundant component in the Arabian peninsula, embracing more than 50% of its Y-chromosomes. ... 2013) Introducing the Algerian Mitochondrial DNA and Y-Chromosome Profiles into the North African Landscape. PLoS ONE 8(2): ...
... with 22-25 clonally abnormal chromosomes, known as HeLa signature chromosomes."[38][39][40][41] The signature chromosomes can ... We mapped by FISH five HPV18 integration sites: three on normal chromosomes 8 at 8q24 and two on derivative chromosomes, der(5) ... including its number of chromosomes. HeLa cells are rapidly dividing cancer cells, and the number of chromosomes varied during ... Chromosome number[edit]. Horizontal gene transfer from human papillomavirus 18 (HPV18) to human cervical cells created the HeLa ...
Chromosome 17[edit]. The most common cause of CMT (70-80% of the cases) is the duplication of a large region on the short arm ... of chromosome 17 that includes the gene PMP22. Some mutations affect the gene MFN2, on chromosome 1, which codes for a ...
Chromosome segregation during meiosis[edit]. Segregation of homologous chromosomes to opposite poles of the cell occurs during ... Proper segregation is essential for producing haploid meiotic products with a normal complement of chromosomes. The formation ... Dynein is involved in the movement of chromosomes and positioning the mitotic spindles for cell division.[2][3] Dynein carries ... "Chromosome- and spindle-pole-derived signals generate an intrinsic code for spindle position and orientation". Nature Cell ...
Y-chromosome DNA[edit]. Y-Chromosome DNA Y-DNA represents the male lineage, the Iranian Y-chromosome pool is as follows where ... In Iran outliers in the Y-chromosomes and Mitochondrial DNA gene pool are consisted by the north Iranian ethnicities, such as ... 2013) Introducing the Algerian Mitochondrial DNA and Y-Chromosome Profiles into the North African Landscape. PLoS ONE 8(2): ... haplogroups, R1 (25%), J2 (23%) G (14%), J1 (8%) E1b1b (5%), L (4%), Q (4%), comprise more than 85% of the total chromosomes.[ ...
Y-chromosome DNA haplogroup[edit]. According to a study published in 2014, the Y-DNA of the Bunun people belongs mainly to ...
... and chromosome structure[edit]. Figure 5. Nucleus of a female amniotic fluid cell. Top: Both X-chromosome ... Chromosome Res 18: 115-125. *^ Taylor JH (1960) Asynchronous duplication of chromosomes in cultured cells of Chinese hamster. J ... Chromosome Res 18: 127-136. *^ Schwaiger M, Stadler MB, Bell O, Kohler H, Oakeley EJ, et al. (2009) Chromatin state marks cell- ... In 1960, J. H. Taylor [8] showed that the active and inactive X chromosomes replicate in a different pattern, with the active X ...
Y-chromosome DNA. Kayser et al. (2006) found four members of O-M95, four members of O-M122(xM134), one member of C-M217, and ... mtDNA and Y Chromosome Gradients Across the Pacific." Molecular Biology and Evolution 23(11):2234-2244. doi:10.1093/molbev/ ... "Major East-West Division Underlies Y Chromosome Stratification across Indonesia." Molecular Biology and Evolution 27(8):1833- ... "Punctuated bursts in human male demography inferred from 1,244 worldwide Y-chromosome sequences." Nature Genetics 2016 June ; ...
Chromosomes[edit]. The initial karyotype includes a set of chromosomes from 2n = 44. They have four pairs of telocentric ... two to four pairs of subtelocentric and one or two large pairs of submetacentric chromosomes. The remaining chromosomes are ... Ulfur Anarson (1974). "Comparative chromosome studies in Cetacea". Institute of Genetics. 77 (1): 1-36. doi:10.1111/j.1601- ... Sperm whales, beaked whales and right whales converge to a reduction in the number of chromosomes to 2n = 42.[33] ...
Genetics and chromosome content[edit]. Like all cells, somatic cells contain DNA arranged in chromosomes. If a somatic cell ... The gametes of diploid organisms contain only single unpaired chromosomes and are called haploid.) Each pair of chromosomes ... By contrast, gametes of diploid organisms contain only half as many chromosomes. In humans, this is 23 unpaired chromosomes. ... However, a large number of species have the chromosomes in their somatic cells arranged in fours ("tetraploid") or even sixes ...
Section structure of Homologous chromosome: Homologous chromosomes are chromosomes which contain the same genes in the same ... For example, Emmer wheat has the AABB chromosome sets (28 total chromosomes) from Triticum monococcum (AA, 14 chromosomes) and ... As this karyotype displays, a diploid human cell contains 22 pairs of homologous chromosomes and 2 sex chromosomes.. ... It is also an amphidiploid, with one set having 20 chromosomes (from B. campestris) and the other having 18 chromosomes (from B ...
Map of Y-chromosome distribution from data derived from "Y chromosome evidence for Anglo-Saxon mass migration" by Weale et al. ... and Y-chromosome DNA differ from the DNA of diploid nuclear chromosomes in that they are not formed from the combination of ... 2003) Y chromosome evidence for Anglo-Saxon mass migration, Molecular Biology and Evolution 19, 7, pp. 1008-1021 ... Y-chromosome evidence[edit]. The inheritance of DNA is a complex process that varies between male and female individuals; ...
"A new method for the study of chromosome rearrangements and the plotting of chromosome maps". Science 78: 585-586. ... Chromosome polymorphism in Drosophila[edit]. In the 1930s Theodosius Dobzhansky and his co-workers collected Drosophila ... Different proportions of chromosome morphs were found in different areas. There is, for example, a polymorph-ratio cline in D. ... It was found that the various chromosome types do not fluctuate at random, as they would if selectively neutral, but adjust to ...
In humans and other mammal species, sex is determined by two sex chromosomes called the X chromosome and the Y chromosome. ... Genetic traits on the X and Y chromosomes are called sex-linked, because they are linked to sex chromosomes, not because they ... Most animals and some plants have paired chromosomes, and are described as diploid. They have two versions of each chromosome, ... Birds have oppositely sex chromosomes: male birds have ZZ and female birds ZW chromosomes. However, inheritance of traits ...
Chromosomes are tiny packages which contain one DNA molecule and its associated proteins. Humans have 46 chromosomes (23 pairs ... Chromosome. A package for carrying DNA in the cells. They contain a single long piece of DNA that is wound up and bunched ... Chromosomes all contain DNA made up of four nucleotides, abbreviated C (cytosine), G (guanine), A (adenine), or T (thymine), ... There are two strings of nucleotides coiled around one another in each chromosome: a double helix. C on one string is always ...
Chromosome. genome: 0.24 - 0.24 Mb. Search for. Structures. Swiss-model. Domains. InterPro. ...
SNPs on chromosome 11. *Coagulopathies. Hidden categories: *CS1: long volume value. *All articles lacking reliable references ...
... called 46/47 XY/XXY mosaic wherein some of the patient's cells contain XY chromosomes, and some contain XXY chromosomes. The 46 ... where a fly possessing two X chromosomes is a female and a fly possessing a single X chromosome is a sterile male, a loss of an ... This may be caused by a nondisjunction event in an early mitosis, resulting in a loss of a chromosome from some trisomic cells. ... In rare cases, intersex conditions can be caused by mosaicism where some cells in the body have XX and others XY chromosomes ( ...
1995). "Mapping of gene loci in the Q13-Q15 region of chromosome 12". Chromosome Res. 3 (4): 261-2. doi:10.1007/BF00713052. ...
Chromosome studies. I. Taxonomic relationships shown in the chromosomes of Tettigidae and Acrididae. V-shaped chromosomes and ... In humans, when a Robertsonian translocation joins the long arm of chromosome 21 with the long arm of chromosomes 14 or 15, the ... Their children, however, may either be normal, carry the fusion chromosome (depending which chromosome is represented in the ... two different chromosomes, not belonging to a homologous pair). A feature of chromosomes that are commonly found to undergo ...
Capelli, C (13 September 2005). "Population Structure in the Mediterranean Basin: A Y Chromosome Perspective". Annals of Human ... inferred by Y-chromosome biallelic variability". American Journal of Physical Anthropology. 121 (3): 270-279. doi:10.1002/ajpa. ... "Differential Greek and northern African migrations to Sicily are supported by genetic evidence from the Y chromosome" ...
Chromosomes and cancer: Theodor Boveri's predictions 100 years later". J. Mol. Med. 80 (9): 545-8. doi:10.1007/s00109-002-0374- ... he developed the concept of chromosome individuality, i.e. the assumption that chromosomes retain their individuality during ... He also reasoned in 1902 that a cancerous tumor begins with a single cell in which the makeup of its chromosomes becomes ... Boveri's work with sea urchins showed that it was necessary to have all chromosomes present in order for proper embryonic ...
The inner vanes of the feathers have velvety barbules.[10] They have a diploid chromosome number of 68 (some older studies ...
The nyala has 55 male chromosomes and 56 female chromosomes.[13] The Y chromosome has been translocated onto the 14th ... "Phylogenomic study of spiral-horned antelope by cross-species chromosome painting". Chromosome Research. 16 (7): 935-47. doi: ... chromosome, as in other tragelaphids, but no inversion of the Y chromosome occurs.[4] Cranial studies have shown that the ...
The chromosome 14 abnormality is observed in about 50% of all cases of myeloma. Deletion of (parts of) chromosome 13 is also ... When chromosomes and genes are damaged, often through rearrangement, this control is lost. Often, a promoter gene moves (or ... A chromosomal translocation between the immunoglobulin heavy chain gene (on chromosome 14, locus q32) and an oncogene (often ... Chromosomal abnormalities commonly found in this disease, like trisomy of multiple odd-numbered chromosomes, t(11;14), and del( ...
... to chromosome 11p15.5--,p15.4 by fluorescence in situ hybridization". Cytogenetics and Cell Genetics. 65 (3): 184-5. doi: ... physical map and repeat polymorphisms of the gastrin/cholecystokinin brain receptor region at the junction of chromosome ... segments 11p15.4 and 15.5". Chromosome Research. 6 (5): 415-8. doi:10.1023/A:1009289625352. PMID 9872672.. ...
Recombination between homeologous chromosomes occurs only rarely, if at all.[68] Since production of genetic variation is weak ... Reproduction in squamate reptiles is ordinarily sexual, with males having a ZZ pair of sex determining chromosomes, and females ... females is thought to ordinarily occur between identical sister chromosomes and occasionally between homologous chromosomes. ... a premeiotic endomitotic event doubles the number of chromosomes. As a result, the mature eggs produced subsequent to the two ...
In my previous article, A Chromosome at a Time with Perl, Part I, I showed you some programming "tricks" that help you avoid ... A Chromosome at a Time with Perl, Part 2. Oct 15, 2003 by ...
Chromosome 16 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome ... "Chromosome 16". Genetics Home Reference. Retrieved 2017-05-06.. *. "Chromosome 16". Human Genome Project Information Archive ... "Chromosome 16: Chromosome summary - Homo sapiens". Ensembl Release 88. 2017-03-29. Retrieved 2017-05-19.. ... See also: Category:Genes on human chromosome 16.. The following is a partial list of genes on human chromosome 16. For complete ...
"chromosome" at OneLook Dictionary Search. French[edit]. Etymology[edit]. 19th century: chromo- +‎ -some, from German Chromosom ... chromosome (plural chromosomes). *(cytology, genetics) A structure in the cell nucleus that contains DNA, histone protein, and ... chromosome in Websters Revised Unabridged Dictionary, G. & C. Merriam, 1913. *chromosome in The Century Dictionary, The ... An illustration of chromosome, with its parts. (1) Chromatid. One of the two identical parts of the chromosome after S phase. ( ...
Coverage emphasizes accounts of experimental studies of chromosome ... ... This journal offers high quality papers on all aspects of chromosome and nuclear biology. ... Chromosomes and their linkage to diseases;. · Chromosome organization within the nucleus;. · Chromatin biology (transcription, ... Chromosome structure, function and mechanics;. · Chromosome and DNA repair; · Epigenetic chromosomal functions (centromeres, ...
... everything you need for studying or teaching Chromosome. ... Immediately download the Chromosome summary, chapter-by-chapter ... Chromosome Segregation and Rearrangement Chromosome segregation refers to the coordinated movement of chromosomes to opposite ... Human Artificial Chromosomes (Hac) Human artificial chromosomes (HAC) are synthetic chromosomes that are structurally similar ... Chromosomes, Eukaryotic Chromosomes are microscopic units containing organized genetic information, eukaryotic chromosomes are ...
... designer chromosome, a genetic structure carefully engineered to foster scientific discovery. ... Artificial chromosomes have been built before. But those were relatively faithful copies of natural chromosomes, the tiny ... In the end, all the yeast carried a bioengineered version of chromosome III. The researchers named the artificial chromosome, ... Previous artificial chromosomes were "copy-and-paste, more or less. It was plagiarism with a few edit marks in it," says Adam ...
Researchers have completed the DNA sequence of chromosome seven, which is home to genes associated with deafness, cystic ... Mapping an Unlucky Chromosome. The number seven is not so lucky when it comes to chromosomes. Chromosome seven is the home of ... Researchers have studied chromosome seven for more than a decade because it contains many genes associated with disease, ... The good news is, researchers now know more about chromosome seven than ever. Research at five centers around the world has ...
They find evidence for two independent sex chromosome originations in mammals and one in birds. Their analysis of the Y/W gene ... See Articles p.488 & p.494 Mammalian Y chromosomes, known for their roles in sex determination and male fertility, often ... They propose that these genes make the Y chromosome essential for male viability and contribute to differences between the ... They conclude that evolution streamlined the gene content of the human Y chromosome through selection to maintain the ancestral ...
The X chromosome spans about 155 million DNA building blocks (base pairs) and represents approximately 5 percent of the total ... The X chromosome is one of the two sex chromosomes in humans (the other is the Y chromosome). The sex chromosomes form one of ... Some cells have the usual two sex chromosomes (either two X chromosomes or one X chromosome and one Y chromosome), and other ... XXXY syndrome have the usual single Y chromosome plus three copies of the X chromosome, for a total of 48 chromosomes in each ...
Chromosome 22 is the second smallest human chromosome, spanning more than 51 million DNA building blocks (base pairs) and ... chromosome consisting of a piece of chromosome 11 attached to a piece of chromosome 22. The extra chromosome is known as a ... A ring chromosome is a circular structure that occurs when a chromosome breaks in two places, the tips of the chromosome are ... Chromosome 22 was the first human chromosome to be fully sequenced.. Identifying genes on each chromosome is an active area of ...
Chromosome, Eukaryotic The deoxyribonucleic acid (DNA) of eukaryotic cells carries the blueprint for the biosynthesis of ... Chromosome, Eukaryotic Biology COPYRIGHT 2002 The Gale Group Inc.. Chromosome, Eukaryotic. The deoxyribonucleic acid (DNA) of ... Chromosome, Eukaryotic Genetics Copyright Genetics Society of America. Chromosome, Eukaryotic. Living organisms are divided ... Each pair of chromosomes can replicate up to nine times; thus, the resultant polytene chromosome can contain up to 1,024 (29) ...
... the generation and engineering of synthetic artificial chromosomes, and the induced de novo platform artificial chromosome ... with the successful production of transgenic animals with engineered chromosomes and chromosomes developed for pharmaceutical ... Mammalian Chromosome Engineering: Methods and Protocols provides the reader with up-to date information on this rapidly ... Authoritative and cutting-edge, Mammalian Chromosome Engineering: Methods and Protocols serves as a bench-side resource for ...
Source for information on Chromosome Mapping: The Gale Encyclopedia of Science dictionary. ... mapping is the assignment of genes to specific locations on a chromosome. A gene map serves many important functions and is ... Chromosome mapping. Chromosome mapping is the assignment of genes to specific locations on a chromosome. A gene map serves many ... chromosomes are lost from a special type of cell and the remaining chromosome that has one gene, but not a different gene, ...
GENETIC diseases might one day be treated by adding an entirely new chromosome to peoples cells. A Canadian company has shown ... GENETIC diseases might one day be treated by adding an entirely new chromosome to peoples cells. A Canadian company has shown ...
The sex chromosomes are called X and Y. For a child to be female, she must inherit an X chromosome from each parent ... Humans have 46 chromosomes (23 pairs). Half of a persons chromosomes come from the mother and half from the father. One of the ... Chromosomes are cell structures that carry genetic material (DNA), or genes. They are a part of every cell in the body. ... The sex chromosomes are called X and Y. For a child to be female, she must inherit an X chromosome from each parent (XX). For a ...
Philadelphia chromosome (en); كروموسوم فيلادلفيا (ar); Philadelphský chromozom (cs); Philadelphia chromosome or Philadelphia ... Cromosoma Philadelphia (it); Chromosome de Philadelphie (fr); Filadelfija kromosom (hr); Cromosoma Filadelfia (gl); 费城染色体 (zh- ... Philadelphia chromosome or Philadelphia translocation is a specific chromosomal abnormality that is associated with chronic ... File nella categoria "Philadelphia chromosome". Questa categoria contiene 11 file, indicati di seguito, su un totale di 11. ...
... scientists have been wondering whether they can fool the machinery of the cell by inserting a synthetic 47th chromosome ... Every human cell carries 46 chromosomes, the DNA-and-protein packages that transmit genes from generation to generation as ... Artificial chromosomes might spare gene therapy patients from these problems. An artificial chromosome can carry any number of ... Their hope is that the fake chromosomes will provide a viable alternative to conventional gene therapy, which typically uses ...
... chimp chromosome 2 and an extra chromosome that does not match any other human chromosome). Second, a chromosome normally has ... First, the banding (or dye pattern) of human chromosome 2 closely matches that of two separate chromosomes found in apes ( ... whereas a normal chromosome has readily identifiable, repeating DNA sequences called telomeres at both ends, chromosome 2 also ... and apes carry a split chromosome. Their focused research led them to find a mutation on one human chromosome that explained ...
... which allows chromosomes to be checked for structural flaws against normal chromosomes but cannot screen all chromosomes ... and the ratio of green to red fluorescence along the length of each chromosome indicates whether the embryos chromosomes have ... Healthy Embryos Show Chromosome Flaws A study involving higher-resolution genetic screening suggests that healthy embryos may ... This means that many embryos must go on to develop into healthy babies even though their chromosomes have defects at this stage ...
Sex chromosome, either of a pair of chromosomes that determine whether an individual is male or female. The sex chromosomes of ... In humans the sex chromosomes comprise one pair of the total of 23 pairs of chromosomes. The other ... individuals having one X chromosome and one Y chromosome (XY) are male. The X chromosome resembles a large autosomal chromosome ... Sex chromosome, either of a pair of chromosomes that determine whether an individual is male or female. The sex chromosomes of ...
There are an estimated 4220 genes on chromosome 1, as discovered during the Human Genome Project around twenty years ago. ... containing a greater number of nucleotides at its 85 loci than all other chromosomes. ... The long (q) arm of chromosome 1. The genes present on the long arm of chromosome 1 include:. * ASPM that determines brain size ... Chromosome 1 is the largest of the 23 chromosomes, containing a greater number of nucleotides at its 85 loci than all other ...
... everything you need for studying or teaching Bacterial artificial chromosome. ... Immediately download the Bacterial artificial chromosome summary, chapter-by-chapter analysis, book notes, essays, quotes, ... Bacterial artificial chromosome Summary. Everything you need to understand or teach Bacterial artificial chromosome. ... Bacterial Artificial Chromosome (Bac) Bacterial artificial chromosomes (BACs) involve a cloning system that is derived from a ...
Two main types of chromosome exist - linear and circular. Circu... ... A chromosome consists of a single double helix of DNA wrapped around a protein scaffold. ... Humans have 46 chromosomes. Females have two X chromosomes, males have X and Y chromosomes. (YY doesnt work, the fetus doesnt ... A chromosome consists of a single double helix of DNA wrapped around a protein scaffold. Two main types of chromosome exist - ...
Find chromosome duplication information, treatments for chromosome duplication and chromosome duplication symptoms. ... MedHelps chromosome duplication Center for Information, Symptoms, Resources, Treatments and Tools for chromosome duplication. ... Posts on chromosome duplication. duplication of7q21.13 {large 1.68 -1.73mb} and deletion of 6p25.1 {large 208.45 - 240.91kb} - ... hi my son has autism and pica, I have just been told he has a duplicate chromosome 3q29 can... ...
Human chromosome 11 DNA sequence and analysis including novel gene identification. Free access. Todd D. Taylor et al. ... Epimutation of the telomeric imprinting center region on chromosome 11p15 in Silver-Russell syndrome. Christine Gicquel et al. ...
This discovery may help to further the development of artificial human chromosomes, which could be used for gene therapies in ... During cell division, the kinetochore provides a point of attachment for the cell skeleton and enables the chromosomes to move ... The cell skeleton, which distributes the chromosomes to the two daughter cells during cell division, attaches to the ... Scientists would like to develop artificial human chromosomes as an alternative to gene therapy using viruses. "Like their ...
... human chromosome (en) 10. kromozom (tr); Chromosome 10 (human), Chromosome 10 (tl); chr10, kromosom 10 (nn); chr10 (nb); ... Human chromosome 10 with ASD genes from IJMS-16-06464.png 606 × 1,510; 183 KB. ... Media in category "Human chromosome 10". The following 30 files are in this category, out of 30 total. ... Human chromosome 10 from Gene Gateway - with label.png 1,439 × 1,654; 102 KB. ...
Y chromosome. Not Exactly Rocket Science. Tag archives for Y chromosome. Renovating a runt - the extreme evolution of the Y ... Men who think that size really matters should probably not think too hard about the Y chromosome. This bundle of genes is the ...
A chromosome which, when stained, produces a banded pattern of alternating light and dark segments (also called a harlequin ... A chromosome which, when stained, produces a banded pattern of alternating light and dark segments (also called a harlequin ... A chromosome is made up of DNA). From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see ...
Presence of XX sex chromosomes increases risk of heart attacks and coronary artery disease New research at the University of ... Not every embryo contains 46 perfect chromosomes. Some have more, others have fewer. The result is a common abnormality known ... Scientists at Johns Hopkins say they have found that people born with abnormally short chromosome endcaps, or telomeres, have ... Eight-five percent of people with lupus are female, and their second X chromosome seems partly to blame. ...
  • Chromosome Identification and Banding Each pair of chromosomes in the eukaryotic cell contains a unique set of genes and thus the DNA sequence is also unique for each different chromosome pair. (bookrags.com)
  • Sex chromosome , either of a pair of chromosomes that determine whether an individual is male or female. (britannica.com)
  • Among human beings the phenomenon of sex determination is the province of a special pair of chromosomes called the sex chromosomes. (brighthub.com)
  • The 23rd pair of chromosomes are two special chromosomes, X and Y, that determine our sex. (nih.gov)
  • Once they've identified each other at some place, they'll begin the process we call synapsis, which involves building this beautiful structure - the synaptonemal complex - and using it to form an intimate association that runs the entire length of each pair of chromosomes," Hawley explains. (medicalnewstoday.com)
  • Either member of a single pair of chromosomes. (dictionary.com)
  • Until this time, the predecessors of the X and the Y had been an equal pair of chromosomes just like any of the others. (nytimes.com)
  • Chromosome 16 is one of the 23 pairs of chromosomes in humans . (wikipedia.org)
  • The X chromosome is one of the two sex chromosomes in humans (the other is the Y chromosome). (medlineplus.gov)
  • Humans normally have 46 chromosomes (23 pairs) in each cell. (medlineplus.gov)
  • Humans have 46 chromosomes (23 pairs). (webmd.com)
  • In particular, it explains that humans have one fewer chromosome pair in their cells than apes, due to a mutation found in chromosome number 2 that caused two chromosomes to fuse into one. (pbs.org)
  • While great apes all have 48 chromosomes (24 pairs), humans have only 46 (23 pairs). (pbs.org)
  • If humans and apes shared a common ancestor, shouldn't both have the same number of chromosomes in their cells? (pbs.org)
  • To corroborate Darwin's theory, scientists would need to find a valid explanation for why a chromosome pair is missing in humans that is present in apes. (pbs.org)
  • The sex chromosomes of human beings and other mammals are designated by scientists as X and Y . In humans the sex chromosomes comprise one pair of the total of 23 pairs of chromosomes. (britannica.com)
  • Humans have 23 pairs of chromosomes which contain all information required for the creation of an offspring. (brighthub.com)
  • In humans, the 22 other pairs of chromosomes - the autosomes - are identical. (dailymail.co.uk)
  • Humans have 23 pairs of chromosomes, 46 in all: 44 autosomes and two sex chromosomes . (conservapedia.com)
  • In humans there are 46 chromosomes, or 23 pairs of chromosomes ( diploid ), in every cell except the mature egg and sperm which have a set of 23 chromosomes ( haploid ). (conservapedia.com)
  • Most eukaryotic cells have a set of chromosomes (46 in humans) with the genetic material spread among them. (dbpedia.org)
  • And because chromosomes come in pairs - 23 sets in humans - the chromosomes must be properly matched up before they can be divvied up. (medicalnewstoday.com)
  • In humans this includes all but the "X" and "Y" chromosomes. (conservapedia.com)
  • This engineered chromosome belongs to yeast, but experts say it can help them understand how genes work in humans as well. (voanews.com)
  • In the past 12 years, with the help of the genome sequencing centers at Washington University in St. Louis and the Baylor College of Medicine in Houston, Dr. Page's group has decoded the DNA sequence of the Y chromosome of eight mammals, including the rhesus monkey and humans. (nytimes.com)
  • Humans have 23 pairs of chromosomes, with one member of every pair being inherited from each parent. (nytimes.com)
  • The Y chromosome is one of two sex chromosomes ( allosomes ) in mammals , including humans , and many other animals. (wikipedia.org)
  • With a 30% difference between humans and chimpanzees, the Y chromosome is one of the fastest-evolving parts of the human genome . (wikipedia.org)
  • The Y chromosomes of humans and other mammals also contain other genes needed for normal sperm production. (wikipedia.org)
  • Under evolutionary assumptions of long and gradual genetic changes, the Y chromosome structures, layouts, genes, and other sequences should be much the same in both species, given the relatively short--according to the evolutionary timeline--six-million-year time span since chimpanzees and humans supposedly diverged from a common ancestor. (freerepublic.com)
  • Chromosome 16 spans about 90 million base pairs (the building material of DNA) and represents just under 3% of the total DNA in cells . (wikipedia.org)
  • The sex chromosomes form one of the 23 pairs of human chromosomes in each cell. (medlineplus.gov)
  • The X chromosome spans about 155 million DNA building blocks (base pairs) and represents approximately 5 percent of the total DNA in cells. (medlineplus.gov)
  • Two copies of chromosome 22, one copy inherited from each parent, form one of the pairs. (medlineplus.gov)
  • Chromosome 22 is the second smallest human chromosome, spanning more than 51 million DNA building blocks (base pairs) and representing between 1.5 and 2 percent of the total DNA in cells. (medlineplus.gov)
  • In 1999, researchers working on the Human Genome Project announced they had determined the sequence of base pairs that make up this chromosome. (medlineplus.gov)
  • Most people with 22q11.2 deletion syndrome are missing about 3 million base pairs on one copy of chromosome 22 in each cell. (medlineplus.gov)
  • or the ancestor had 23 pairs, and apes carry a split chromosome. (pbs.org)
  • The other 22 pairs of chromosomes are called autosomes . (britannica.com)
  • Out of the 23 pairs of chromosomes the sex chromosomes X & Y determine the sex of an embryo. (brighthub.com)
  • The Y chromosome is made up of some 58 million base pairs and more than 95% of it is male specific. (brighthub.com)
  • They could see that chromosomes came in pairs, and that human cells all contained 23 matching pairs. (conservapedia.com)
  • In 1991 a project called the Human Genome Project began to use computers to map the three billion base pairs which make up the 46 human chromosomes. (conservapedia.com)
  • This pattern is seen by dividing a chromosome into intervals along its length, determining the frequencies of events occurring in each individual interval and then examining all pairs of intervals with respect to the observed frequency of chromosomes with events in both intervals ("double events") as compared to that expected on the basis of independent occurrence ( Fig. 1 D , green). (pnas.org)
  • Our genetic information is stored in 23 pairs of chromosomes that vary widely in size and shape. (nih.gov)
  • any of several threadlike bodies, consisting of chromatin, that carry the genes in a linear order: the human species has 23 pairs, designated 1 to 22 in order of decreasing size and X and Y for the female and male sex chromosomes respectively. (dictionary.com)
  • We have 46 chromosomes in our cells arranged into 23 pairs. (kickstarter.com)
  • One of these pairs forms the chromosomes that determine our sex, the X and Y chromosomes. (kickstarter.com)
  • Most people have 23 pairs of chromosomes, and you received half your chromosomes from your mother and the other half from your father. (kidshealth.org)
  • Before generating eggs and sperm, the 23 pairs of chromosomes line up and each chromosome exchanges chunks of DNA with its partner, a process known as recombination. (nytimes.com)
  • Each human cell contains 23 pairs of chromosomes that carry DNA within their nucleus. (psychologytoday.com)
  • The DNA in the human Y chromosome is composed of about 59 million base pairs . (wikipedia.org)
  • Stevens proposed that chromosomes always existed in pairs and that the Y chromosome was the pair of the X chromosome discovered in 1890 by Hermann Henking . (wikipedia.org)
  • That's actually shorter than the yeast's natural chromosome, which contained 316,667 base pairs. (cnn.com)
  • Everyone inherits 23 chromosomes from each parent, 46 in all, making 23 matched pairs-with one exception. (psychologytoday.com)
  • The C . elegans has 5 chromosomes autosomes plus the sex chromosome X. Totally, it is made up of nearly 100 million base pairs and 19000 genes [ 3 - 5 ]. (hindawi.com)
  • By inspection through the microscope, he counted 24 pairs, which would mean 48 chromosomes. (wikipedia.org)
  • The chromosomes of most bacteria, which some authors prefer to call genophores, can range in size from only 130,000 base pairs in the endosymbiotic bacteria Candidatus Hodgkinia cicadicola and Candidatus Tremblaya princeps, to more than 14,000,000 base pairs in the soil-dwelling bacterium Sorangium cellulosum. (wikipedia.org)
  • Further information: As S. Sozhamannan and others have reported, Vibrio cholerae has a gene acquisition system located on its small chromosome as well as hot spots for DNA rearrangement. (nsf.gov)
  • The small chromosome contains a large percentage of hypothetical genes, more genes that appear to have origins other than the Proteobacteria, a gene capture system (integron island) that suggests this may have been a mega-plasmid captured by an ancestral Vibrio species. (nsf.gov)
  • The following are some of the gene count estimates of human chromosome 16. (wikipedia.org)
  • Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction ). (wikipedia.org)
  • Comparisons of Y-chromosome sequences in various mammals reveal abundant gene loss early in the chromosome's evolution but remarkable gene stability across the Y chromosomes of extant species. (nature.com)
  • 4 ( page 488 ) present extensive accounts of gene evolution on the Y chromosome. (nature.com)
  • They show that, although there was a period of rapid degeneration and gene loss during its early evolution, the genes that are conserved across the Y chromosomes of extant mammals (and the sex-determining W chromosomes of birds) have since been remarkably stable. (nature.com)
  • The SRY gene, which is normally found on the Y chromosome, is misplaced in this disorder, almost always onto an X chromosome. (medlineplus.gov)
  • A fetus with an X chromosome that carries the SRY gene will develop as a male despite not having a Y chromosome. (medlineplus.gov)
  • The translocation involved in this condition, written as t(9;22), fuses part of the ABL1 gene from chromosome 9 with part of the BCR gene from chromosome 22, creating an abnormal fusion gene called BCR-ABL1 . (medlineplus.gov)
  • The abnormal chromosome 22, containing a piece of chromosome 9 and the fusion gene, is commonly called the Philadelphia chromosome. (medlineplus.gov)
  • A detailed chromosome map also provides methods to study how genes are segregated and how genetic heterogeneity (variation between a particular gene maternally inherited and the same gene with a slightly different sequence that is paternally inherited) can help identify disease genes. (encyclopedia.com)
  • In somatic cell genetic methods, chromosomes are lost from a special type of cell and the remaining chromosome that has one gene, but not a different gene, would suggest that they are located on different chromosomes. (encyclopedia.com)
  • This method allows scientists to identify which chromosome contains the gene, and represents one of the first mapping methods used by scientists. (encyclopedia.com)
  • Cytogenetic techniques refer to utilization of karyotype preparations, a technique that allows scientists to visualize of chromosomes, using fluorescence so that a fluorescently-labeled gene will reveal where the gene is found on the chromosome. (encyclopedia.com)
  • Gene dosage studies uses, for example, numerical abnormalities to determine indirectly the location of the gene on a chromosome. (encyclopedia.com)
  • In Down syndrome , there can be three chromosome number 21 (Trisomy 21), resulting in three copies of the gene and therefore, three times as much protein. (encyclopedia.com)
  • In this case, a gene can be localized to chromosome 21 if there is three times as much protein in a cell with three 21 chromosomes. (encyclopedia.com)
  • Their hope is that the fake chromosomes will provide a viable alternative to conventional gene therapy, which typically uses viruses to deliver gene replacements in treatment of such diseases as hemophilia and cystic fibrosis. (technologyreview.com)
  • Artificial chromosomes might spare gene therapy patients from these problems. (technologyreview.com)
  • More recently, Chromos scientists proved that they can raise red blood cell counts in mice by injecting cells that contain artificial chromosomes bearing the gene for erythropoeitin, a protein that stimulates blood cell production. (technologyreview.com)
  • Michle Calos, a Stanford University geneticist who previously had worked with artificial chromosomes, has since shifted her focus to other gene-therapy methods such as inserting therapeutic genes at specific places on natural chromosomes. (technologyreview.com)
  • This discovery may help to further the development of artificial human chromosomes, which could be used for gene therapies in medicine. (redorbit.com)
  • Scientists would like to develop artificial human chromosomes as an alternative to gene therapy using viruses. (redorbit.com)
  • It is the presence or the absence of the SRY gene (sex determining region of the Y chromosome) that determines which way the embryo will develop. (brighthub.com)
  • He concluded that the gene for white eyes must be on a chromosome that was related to being male. (conservapedia.com)
  • This method of mapping a gene to a particular band of the chromosome is called cytogenetic mapping. (nih.gov)
  • For example, the hemoglobin beta gene ( HBB ) is found on chromosome 11p15.4. (nih.gov)
  • This means that the HBB gene lies on the short arm (p) of chromosome 11 and is found at the band labeled 15.4. (nih.gov)
  • The stable gradient of AIMS abundance from replication origin to terminus suggests that the replicore acts as a target of selection, where selection for chromosome architecture results in the maintenance of gene order and in the lack of high-frequency DNA inversion within replicores. (springer.com)
  • How macromolecules of DNA fold into chromosomes is thought to have a crucial role in biological processes like gene regulation, DNA replication and cell differentiation. (eurekalert.org)
  • He said there is already evidence for the idea that actual gene regulatory processes are influenced by the chromosomes' structures. (eurekalert.org)
  • Genetic control over sex probably began when a gene on one of the X chromosomes called SOX3 became converted to SRY, the gene that determines maleness, and thus the Y chromosome came into being. (nytimes.com)
  • Using a synthetic chromosome modified in this way means it will be easier to execute multiple, simultaneous gene knockouts. (economist.com)
  • In mammals, the Y chromosome contains the gene SRY , which triggers male development. (wikipedia.org)
  • In mammals, the Y chromosome contains a gene, SRY , which triggers embryonic development as a male. (wikipedia.org)
  • The title of the recent journal article accurately sums up the research findings: 'Chimpanzee and Human Y Chromosomes are Remarkably Divergent in Structure and Gene Content. (freerepublic.com)
  • As far as looking at specific genes, the chimp and human Y chromosomes had a dramatic difference in gene content of 53 percent. (freerepublic.com)
  • The human Y chromosome contains a third more gene categories--entirely different classes of genes--compared to chimps. (freerepublic.com)
  • What is the difference between a chromosome and a gene? (theregister.co.uk)
  • A gene is located on a chromosome. (theregister.co.uk)
  • When "mapping" all genes on all human chromosomes was first seriously conceived, it was called the Human Genome Project - a combination of gene and chromosome. (theregister.co.uk)
  • Chromosomal Aberrations Chromosomal aberrations are abnormalities in the structure or number of chromosomes and are often responsible for genetic disorders. (bookrags.com)
  • Chromosomal Banding A chromosome banding pattern is comprised of alternating light and dark stripes, or bands, that appear along its length after being stained with a dye. (bookrags.com)
  • Chromosomal Theory of Inheritance The chromosomal theory of inheritance is the idea that genes, the units of heredity, are physical in nature and are found in the chromosomes. (bookrags.com)
  • Chromosomal Mutations and Abnormalities Chromosome abnormalities describe alterations in the normal number of chromosomes or structural problems within the chromosomes themselves. (bookrags.com)
  • The following chromosomal conditions are associated with changes in the structure or number of copies of x chromosome. (medlineplus.gov)
  • The following chromosomal conditions are associated with changes in the structure or number of copies of chromosome 22. (medlineplus.gov)
  • The rapid progression of genetics and molecular biology has turned chromosomal engineering from science fiction to reality, with the successful production of transgenic animals with engineered chromosomes and chromosomes developed for pharmaceutical protein production which are now ready for the medical industry. (springer.com)
  • Mammalian Chromosome Engineering: Methods and Protocols provides the reader with up-to date information on this rapidly evolving field and strives to take the reader into the exciting realm of chromosomal engineering from the basic principles to the practical applications of these new technologies. (springer.com)
  • Philadelphia chromosome or Philadelphia translocation is a specific chromosomal abnormality that is associated with chronic myelogenous leukemia (CML). (wikimedia.org)
  • Neither Lavery nor Vanneste suggests giving up on IVF screening completely, but they both argue that chromosomes from more or less developed embryos may provide more reliable results because chromosomal instability is not as much of an issue then. (technologyreview.com)
  • Chromosomes are made of DNA, and genes are special units of chromosomal DNA. (nih.gov)
  • Chromosomal abnormalities result from mutations which change the number of chromosomes (numerical abnormalities) or change the structure of the chromosome (structural abnormalities). (greenfacts.org)
  • Chromosomal distribution of specific genes and DNA sequences can help to distinguish between related species with very similar, apparently identical, chromosomes. (redorbit.com)
  • While chromosome full alignment includes several stages, the early physical contact and colocalization could be driven by specific chromosomal regions bridged by molecular mediators. (genetics.org)
  • This book continues to fulfill that need, and is strengthened by the complete revision of material on the molecular genetics of chromosomes and chromosomal defects. (springer.com)
  • The sexual difference at the chromosomal level provides: XX chromosomes for hermafrodite and X0 for the male. (hindawi.com)
  • The very large chromosomes in the salivary gland cells of Drosophila and other insects have furnished valuable material for the study of genetics . (factmonster.com)
  • American biologist Walter Sutton knew Mendel's principles of genetics work on peas, and suggested that chromosomes held the secret of inheritance. (conservapedia.com)
  • New research, presented this week at the European Society of Human Genetics conference in Barcelona, Spain, demonstrates that men whose blood cells lack Y chromosomes are more susceptible to Alzheimer's disease. (medicalnewstoday.com)
  • Genetics) a graphic representation of the positions of genes on chromosomes, obtained by observation of chromosome bands or by determining the degree of linkage between genes. (thefreedictionary.com)
  • Also, men with significant Y chromosome loss in their blood cells had a much higher risk of dying from cancer , according to the study presented at the annual meeting of the American Society of Human Genetics, in San Diego on Oct. 21. (medicinenet.com)
  • Fusion of the male and female gametes in fertilization restores the diploid number in the fertilized egg, or zygote, which thus contains two sets of homologous chromosomes, one from each parent. (factmonster.com)
  • During meiosis, homologous maternal and paternal chromosomes ("homologs") become linked by cytologically observable connections, "chiasmata" ( Fig. 1 A ). Each chiasma is the site of a DNA crossover between one sister of each homolog. (pnas.org)
  • Clerget M (1991) Site-specific recombination promoted by a short DNA segment of plasmid R1 and by a homologous segment in the terminus region of the Escherichia coli chromosome. (springer.com)
  • During this process, homologous chromosomes pair at the cellular midline allowing for exchange of deoxyribonucleic acid (DNA) between parental alleles and stabilisation of the chromosome structures during separation. (els.net)
  • Unlike the paired autosomes, in which each member normally carries alleles (forms) of the same genes, the paired sex chromosomes do not carry an identical complement of genetic information. (britannica.com)
  • Scientists believe that the modern Y chromosome evolved from the autosomes and slowly specialized into functioning as a sex determining agent. (brighthub.com)
  • The transmission pattern of the human X chromosome reduces its population size relative to the autosomes, subjects it to disproportionate influence by female demography, and leaves X-linked mutations exposed to selection in males. (scienceblogs.com)
  • We found that X chromosomes tend to be more differentiated between human populations than autosomes with several notable exceptions. (scienceblogs.com)
  • The X and Y chromosomes are thought to have evolved from a pair of identical chromosomes, [10] [11] termed autosomes , when an ancestral animal developed an allelic variation, a so-called "sex locus" - simply possessing this allele caused the organism to be male. (wikipedia.org)
  • One of the main deficiencies with the original chimpanzee genome sequence published in 20053 was that it was a draft sequence and only represented a 3.6-fold random coverage of the 21 chimpanzee autosomes, and a 1.8-fold redundancy of the X and Y sex chromosomes. (freerepublic.com)
  • And third, whereas a normal chromosome has readily identifiable, repeating DNA sequences called telomeres at both ends, chromosome 2 also has telomere sequences not only at both ends but also in the middle. (pbs.org)
  • Linear chromosomes also have telomeres , sections of DNA at each end that can be replicated without using DNA polymerase and thus preventing the chromosome becoming shorter each time it's replicated, and centromeres , the point at which the two chromatids present during DNA replication are joined together. (everything2.com)
  • Scientists at Johns Hopkins say they have found that people born with abnormally short chromosome endcaps, or telomeres, have immune system cells that age and die prematurely. (news-medical.net)
  • Elderly people are more likely to develop cognitive problems if their telomeres - the stretches of DNA that cap the ends of chromosomes - are shorter than those of their peers. (newscientist.com)
  • The scientists were especially interested in their telomeres-protective DNA sequences at the ends of chromosome s that act a bit like the caps on the ends of shoelaces. (dictionary.com)
  • It centers on structures at the end of chromosomes called telomeres and an enzyme that forms them, called telomerase. (cnn.com)
  • Several mechanisms could contribute to the outcome of the process, e.g ., constrained motion of chromosomes in territories, bouquet formation at telomeres, and tethering to the nuclear envelope. (genetics.org)
  • In fact, adult cells in most regions of the brain appear to function normally even when their chromosomes are deprived of protective caps, called telomeres. (scripps.edu)
  • Using a mouse model designed to have dysfunctional telomere, the researchers confirmed that-as previously shown-developing cells do indeed need telomeres to protect their chromosomes early on in development. (scripps.edu)
  • Chromosome Chromosomes are structures in the nucleus of the cell that contain the DNA or hereditary material which form genes. (bookrags.com)
  • But those were relatively faithful copies of natural chromosomes, the tiny thread-like structures made of tightly packed DNA that serve as the body's blueprints. (usatoday.com)
  • Chromosomes are cell structures made up of genetic material (DNA). (webmd.com)
  • The information molecule, the DNA, is tightly packed into structures called chromosomes which are responsible for carrying over the information from the parent to the offspring. (brighthub.com)
  • They hope to develop a theory that predicts the folding mechanisms and resulting structures of chromosomes in the same general way Wolynes helped revolutionize the view of protein folding through the concept of energy landscapes. (eurekalert.org)
  • In such a state, the domains remain fluid but become ordered, allowing for locally funneled landscapes that lead to the "ideal" chromosome structures that resemble the speculative versions seen in textbooks. (eurekalert.org)
  • But biologically it is true, because both are eukaryotes, meaning that they have proper cell nuclei with several linear chromosomes in them, and also lots of other complex and well-defined cellular structures, called organelles. (economist.com)
  • In spite of their appearance, chromosomes are structurally highly condensed which enables these giant DNA structures to be contained within a cell nucleus (Fig. 2). (wikiversity.org)
  • The self assembled microtubules form the spindle, which attaches to chromosomes at specialized structures called kinetochores, one of which is present on each sister chromatid. (wikiversity.org)
  • The German scientists Schleiden, Virchow and Bütschli were among the first scientists who recognized the structures now familiar as chromosomes. (wikipedia.org)
  • Chromosomes The genetic material in plants, animals, and fungi is called deoxyribonucleic acid (DNA), a long, linear polymer that is physically organized at the microscopic level into chromosomes. (bookrags.com)
  • Chromosome A chromosome consists of the body's genetic material, the deoxyribonucleic acid, or DNA, along with many kinds of protein. (bookrags.com)
  • The principal constituents of the chromosomes are nucleoproteins containing deoxyribonucleic acid, or DNA (see nucleic acid ). (factmonster.com)
  • When the germ cells divide in the two-step process of meiosis , the chromosomes are separated in such a way that each daughter cell receives a haploid (half the diploid) number of chromosomes. (factmonster.com)
  • This path to maleness or femaleness originates at the moment of meiosis , when a cell divides to produce gametes , or sex cells having half the normal number of chromosomes. (britannica.com)
  • Cell division in the germ cells, eggs and sperm (meiosis), results in the creation of daughter cells with half the number of chromosomes as the original cell (haploid cells). (conservapedia.com)
  • En las divisiones celulares (mitosis y meiosis) el cromosoma presenta su forma más conocida, cuerpos bien delineados en forma de X, debido al alto grado de compactación y duplicación. (dbpedia.org)
  • Meiosis reduces the number of chromosomes carried by an individual's regular cells by half, allocating precisely one copy of each chromosome to each egg or sperm cell and thus ensuring that the proper number of chromosomes is passed from parent to offspring. (medicalnewstoday.com)
  • Some model organisms employed in the study of meiosis, such as yeast and the roundworm Caenorhabditis elegans, use the ends of their chromosomes to facilitate the process. (medicalnewstoday.com)
  • But the fruit fly Drosophila melanogaster - the model organism in which meiosis has been thoroughly studied for more than a century, and which Hawley has studied for almost 40 years - has unusual chromosome ends that don't lend themselves to the same kind of clustering. (medicalnewstoday.com)
  • So even though the study of meiosis began in Drosophila, we really haven't had any idea how chromosomes initiate synapsis in Drosophila," Hawley says. (medicalnewstoday.com)
  • Research at five centers around the world has culminated in the publication of the complete DNA sequence of chromosome seven in the July 10 issue of Nature . (wired.com)
  • The Y chromosome is so hard to decode that many early versions of the human genome sequence just omitted it. (nytimes.com)
  • While the male baby is in the womb, the Y chromosome begins a sequence of masculinizing events in both body and brain, particularly the exposure to androgens, which greatly impacts behavior after birth. (psychologytoday.com)
  • This page lists all sequence and annotation changes that have been made to the Chromosome VII systematic reference sequence since its intial release on 1996-07-31. (yeastgenome.org)
  • The sequence of Chromosome VII has been updated 125 times, affecting 87 features. (yeastgenome.org)
  • The result is a data set consisting of thousands of random sequencing contigs, or islands of contiguous sequence that need to be oriented and placed in position on their respective chromosomes. (freerepublic.com)
  • Before getting into the details of their results, it is important to understand that for the first time, the chimpanzee DNA sequence for a chromosome was assembled and oriented based on a Y chromosome map/framework built for chimpanzee and not human. (freerepublic.com)
  • As a result, the chimpanzee DNA sequence could then be more accurately compared to the human Y chromosome because it was standing on its own merit. (freerepublic.com)
  • On the human Y chromosome, there were found four major categories of DNA sequence that occupy specific regions. (freerepublic.com)
  • Just as a continent like Europe is divided into countries because of different people groups, so are chromosomes with different categories of DNA sequence. (freerepublic.com)
  • One sequence class, or category containing DNA with a characteristic sequence, within the chimpanzee Y chromosome had less than 10 percent similarity with the same class in the human Y chromosome, and vice versa. (freerepublic.com)
  • Prokaryotic chromosomes have less sequence-based structure than eukaryotes. (wikipedia.org)
  • 2004). "The sequence and analysis of duplication-rich human chromosome 16" (PDF). (wikipedia.org)
  • Researchers have chopped, spliced and manipulated DNA to craft the first "designer chromosome," a genetic structure carefully engineered to foster scientific discovery. (usatoday.com)
  • To build the first artificial copy of an entire yeast chromosome, an international team of researchers produced a modified version of yeast chromosome III. (usatoday.com)
  • The researchers named the artificial chromosome, described in this week's edition of Science , synIII, derived from the word "synthetic. (usatoday.com)
  • In making the souped-up yeast chromosome, the researchers altered roughly 15% of the original. (usatoday.com)
  • The good news is, researchers now know more about chromosome seven than ever. (wired.com)
  • The researchers have been studying chromosome seven for about a decade. (wired.com)
  • The researchers say the chromosome seven data will also help researchers better understand the genetic mutations that cause acute leukemia. (wired.com)
  • Researchers have studied chromosome seven for more than a decade because it contains many genes associated with disease, including cystic fibrosis. (wired.com)
  • The researchers' data also provide a detailed picture of the evolutionary forces acting on the sex chromosomes, and offer a plausible explanation for the functional coherence of Y-linked genes across these species. (nature.com)
  • Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. (medlineplus.gov)
  • As doctors and researchers have learned more about the differences between these sex chromosome disorders, they have started to consider them as separate conditions. (medlineplus.gov)
  • Researchers believe that several critical genes near the end of the q arm of chromosome 22 are lost when the ring chromosome 22 forms. (medlineplus.gov)
  • Willard and Athersys researchers created the first human artificial chromosomes five years ago. (technologyreview.com)
  • To the researchers' surprise, they found that 90 percent of the cells had duplicated or missing chunks of chromosomes. (technologyreview.com)
  • An embryo with two X chromosomes will become a girl, while an embryo with an X-Y combination results in a boy but Australian researchers. (dailymail.co.uk)
  • In a study published last month, researchers at the Massachusetts Institute of Technology tracked an important part of the memory-making process at the molecular scale in engram cells' chromosome s. (dictionary.com)
  • Such questions motivate researchers to compare chromosomes in closely related species. (redorbit.com)
  • To understand the nature of chromosome changes in the voles Microtus savii, researchers from the Rome State University "Sapienza" launched a molecular cytogenetic study. (redorbit.com)
  • By localization of such molecular "markers" on chromosomes, or so-called "physical mapping", researchers evidence differences that are normally invisible in microscope. (redorbit.com)
  • Rice University researchers Peter Wolynes, left, and Bin Zhang are working to formulate an energy-landscape theory for chromosomes. (eurekalert.org)
  • The researchers also describe in today's issue of Science another seven genes that are unique to the Y chromosome and lie in regions known to be involved in infertility. (sciencemag.org)
  • Panning for gold, the researchers examined cells from human testes, where they guessed genes on the Y chromosome should be particularly active. (sciencemag.org)
  • When researchers were first able to analyze the genetic content of the Y chromosome, they found it had shed hundreds of genes over time, explaining why it was so much shorter than its partner, the X chromosome. (nytimes.com)
  • The explosion of information on human genetic diseases has meant that there is a greater need than ever for students, practising physicians, laboratory technicians, and researchers to have a concise, up-to-date summary of the normal and abnormal behavior of chromosomes. (springer.com)
  • This age-related loss is common among men and could explain why men tend to die younger and have higher rates of certain cancers than women, who do not have a Y chromosome, the researchers say. (medicinenet.com)
  • Researchers were already able to duplicate a chromosome on a computer four years ago , build it in the lab, insert it into a cell and watch it work. (cnn.com)
  • Chromosomes, Artificial Artificial chromosomes are laboratory constructs that contain DNA sequences and that perform the critical functions of natural chromosomes. (bookrags.com)
  • Chromosome, Prokaryotic The bacterial or prokaryotic chromosome differs in many ways from that of the eukaryote. (bookrags.com)
  • Everything you need to understand or teach Bacterial artificial chromosome . (bookrags.com)
  • Bacterial Artificial Chromosomes Bacterial artificial chromosomes (BACs) are large F-based plasmid vectors that can accommodate large inserts of DNA. (bookrags.com)
  • Bacterial Artificial Chromosome (Bac) Bacterial artificial chromosomes (BACs) involve a cloning system that is derived from a particular plasmid found in the bacterium Escherichia coli. (bookrags.com)
  • Bacterial chromosomes are immense polymers whose faithful replication and segregation are crucial to cell survival. (springer.com)
  • The ability of proteins such as FtsK to move unidirectionally toward the replication terminus, and direct DNA translocation into the appropriate daughter cell during cell division, requires that bacterial genomes maintain an architecture for the orderly replication and segregation of chromosomes. (springer.com)
  • Each chromosome carries a single strand of DNA that threads. (bookrags.com)
  • Every human cell carries 46 chromosomes, the DNA-and-protein packages that transmit genes from generation to generation as cells divide. (technologyreview.com)
  • The X chromosome, being larger, carries many more genes than does the Y. Traits controlled by genes found only on the X chromosome are said to be sex-linked ( see linkage group ). (britannica.com)
  • [1] The chromosome carries portions of the hereditary information of an organism. (conservapedia.com)
  • Each of Hsal's cells carries 25 copies of its chromosome , which fragment and reassemble after a high radiation dosage. (dictionary.com)
  • The X chromosome carries at least 150 genes linked to intelligence . (psychologytoday.com)
  • [6] The human Y chromosome carries an estimated 100-200 genes, with between 45 and 73 of these protein-coding. (wikipedia.org)
  • Wilhelm Roux suggested that each chromosome carries a different genetic configuration, and Boveri was able to test and confirm this hypothesis. (wikipedia.org)
  • The complete genome of Vibrio cholerae El Tor N16961 consists of two circular chromosomes (2,961,146 and 1,072,313 base pair) with 3,890 predicted open reading frames (2,775 and 1,115 on each chromosome respectively). (nsf.gov)
  • An artificial chromosome can carry any number of genes, is ignored by the immune system, and functions independently of other chromosomes, so the technique "represents potentially a response or an answer to those challenges," says Huntington F. Willard, director of the Duke University Institute for Genome Sciences and Policy. (technologyreview.com)
  • There are an estimated 4220 genes on chromosome 1, as discovered during the Human Genome Project around twenty years ago. (news-medical.net)
  • Centromeres are specialised regions of the genome, which can be identified under the microscope as the primary constriction in X-shaped chromosomes. (redorbit.com)
  • But the human Y-chromosome is still one of the smallest in the genome. (dailymail.co.uk)
  • A few days ago I discussed a new paper which explores the patterns of natural selection in the genome of the X chromosome. (scienceblogs.com)
  • Since the font is small, I will tell you in general it confirms that the X chromosome shows more between population variance than the autosomal genome when comparing between continents, but the pattern was less clear within continents, and for East Asian populations the X chromosome is actually less differentiated than the autosome. (scienceblogs.com)
  • He holds out hope that the theory developed in this study will lead to a more detailed view of chromosome conformations and will result in a better understanding of the relationships of the structure, dynamics and function of the genome. (eurekalert.org)
  • Besides its long-known role of reversing the default state of being female, the Y chromosome includes genes required for the general operation of the genome, according to two new surveys of its evolutionary history. (nytimes.com)
  • The next step is to make more yeast chromosomes-eventually creating a completely synthetic genome. (economist.com)
  • In viruses, the DNA molecules present in mitochondria and chloroplasts are commonly referred to as chromosomes, despite being naked molecules, as they constitute the complete genome of the organism or organelle. (wikiversity.org)
  • In addition most eukaryotes have a small circular mitochondrial genome, and some eukaryotes may have additional small circular or linear cytoplasmic chromosomes. (wikiversity.org)
  • Optical genome mapping (8) of R1101 generated a consensus full-length map showing a circular chromosome map of [much greater than] 4. (thefreedictionary.com)
  • Disease genes and chromosomes: disease maps of the human genome. (wikipedia.org)
  • Chromosome Segregation and Rearrangement Chromosome segregation refers to the coordinated movement of chromosomes to opposite poles of the cell during either cellular reproduction (mitosis) or the pro. (bookrags.com)
  • We have shown that chromosome segregation and DNA repair are partly dealt with by the same machinery. (eurekalert.org)
  • APC/C regulates chromosome segregation through degradation of proteins such as CycB that permits cytokinesis to progress. (els.net)
  • In animal cells, chromosomes reach their highest compaction level in anaphase during chromosome segregation. (wikipedia.org)
  • During M phase, each chromosome is duplicated, and each replica remains attached to its original at the centromere portion of the chromosome. (encyclopedia.com)
  • Second, a chromosome normally has one centromere, or central point at which a chromosome's two identical strands are joined. (pbs.org)
  • Yet remnants of a second, presumably inactive centromere can be found on human chromosome 2. (pbs.org)
  • Each chromosome has a constriction point called the centromere , which divides the chromosome into two sections, or "arms. (conservapedia.com)
  • The location of the centromere on each chromosome gives the chromosome its characteristic shape, and can be used to help describe the location of specific genes. (conservapedia.com)
  • [4] There is also a telomere region within the human chromosome two, as well as a non-functional second centromere. (conservapedia.com)
  • Near the center of each chromosome is its centromere, a narrow region that divides the chromosome into a long arm (q) and a short arm (p). (nih.gov)
  • Each chromosome has one centromere, with one or two arms projecting from the centromere, although under most circumstances these arms are not visible as such. (wikiversity.org)
  • This compact form makes the individual chromosomes visible, and they form the classic four arm structure, a pair of sister chromatids attach to each other at the centromere. (wikiversity.org)
  • Before this happens, each chromosome is duplicated (S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. (wikipedia.org)
  • Various proteins act to stabilize DNA in interphase, while additional proteins are required to condense the chromosomes over a thousandfold to form the compact chromosomes required for mitosis and cell division. (encyclopedia.com)
  • The term chromosome is usually reserved for the structure when it is condensed and readily visible during cell division (see mitosis ). (factmonster.com)
  • Cell division in somatic cells (mitosis) results in the creation of daughter cells with the same number of chromosomes as the original cell, a total of 46 chromosomes in a human. (conservapedia.com)
  • All chromosomes normally appear as an amorphous blob under the microscope and only take on a well-defined shape during mitosis . (wikipedia.org)
  • It is entirely coincidental that the Y chromosome, during mitosis , has two very short branches which can look merged under the microscope and appear as the descender of a Y-shape. (wikipedia.org)
  • Chromosome Chromosomes are thread-like bodies in the cell nucleus of all plants and animals that hold the genes--the blueprints of heredity. (bookrags.com)
  • chromosome krō´məsōm˝ [ key ] , structural carrier of hereditary characteristics, found in the nucleus of every cell and so named for its readiness to absorb dyes. (factmonster.com)
  • This deactivated X chromosome can be seen as a small, dark-staining structure-the Barr body -in the cell nucleus . (britannica.com)
  • The new results are concerned with a phenomenon called cohesion, whereby two copies of a chromosome in the cell nucleus are held tightly together by a protein complex called cohesin. (eurekalert.org)
  • Because the chromosomes in a nucleus must divide in half to form ova and pollen , triploids, with an odd number of chromosomes, are usually sterile. (daylilies.org)
  • In eukaryotes nuclear chromosomes are packaged by proteins (particularly histones) into chromatin to fit the massive molecules into the nucleus. (wikiversity.org)
  • Eukaryotes (cells with nuclei such as plants, yeast, and animals) possess multiple large linear chromosomes contained in the cell's nucleus. (wikiversity.org)
  • Chromatin is the complex of DNA and protein found in the eukaryotic nucleus which packages chromosomes. (wikiversity.org)
  • Individual chromosomes cannot be distinguished at this stage - they appear in the nucleus as a homogeneous tangled mix of DNA and protein. (wikiversity.org)
  • It is the only chromosome in an organism that isn't essential for life - women survive just fine without one, after all. (dailymail.co.uk)
  • A chromosome (from Greek: χρῶμα color and σῶμα body) is a packaged and organized structure containing most of the DNA of a living organism. (dbpedia.org)
  • Each DNA containing organism has a different number of chromosomes and they, in turn, can exhibit a wide variety of shapes. (kickstarter.com)
  • A chromosome is a long DNA molecule with part or all of the genetic material of an organism. (wikipedia.org)
  • A ring chromosome is a circular structure that occurs when a chromosome breaks in two places, the tips of the chromosome are lost, and the broken ends fuse together. (medlineplus.gov)
  • Two main types of chromosome exist - linear and circular . (everything2.com)
  • Circular chromosomes are pretty much limited to the prokaryotes , while linear ones are found in both prokaryotes and eukaryotes . (everything2.com)
  • Bacteria, in contrast, are prokaryotes-meaning their DNA is arranged in small, circular chromosomes which float around in more or less organelleless cells. (economist.com)
  • Typically eukaryotic cells have large linear chromosomes and prokaryotic cells smaller circular chromosomes, although there are many exceptions to this rule. (wikiversity.org)
  • In prokaryotes, a small circular DNA molecule may be called either a plasmid or a small chromosome. (wikiversity.org)
  • The prokaryotes - bacteria and archaea - typically have a single circular chromosome, but many variations exist. (wikipedia.org)
  • Human Artificial Chromosomes (Hac) Human artificial chromosomes (HAC) are synthetic chromosomes that are structurally similar to normal chromosomes that, in addition to being artificially created, car. (bookrags.com)
  • The research paves the way for producing new medicines and even biofuels from life forms with artificial chromosomes. (usatoday.com)
  • Artificial chromosomes have been built before. (usatoday.com)
  • Previous artificial chromosomes were "copy-and-paste, more or less. (usatoday.com)
  • The five overview and ten protocol chapters cover the engineering of chromosomes with extrachromosomal vectors and transposon systems, the manipulation of naturally occurred minichromosomes, the generation and engineering of synthetic artificial chromosomes, and the induced de novo platform artificial chromosome system. (springer.com)
  • they are testing artificial chromosomes as a safe and effective way to introduce therapeutic genes into patients suffering from deadly genetic disorders. (technologyreview.com)
  • In the artificial chromosome they have all been converted to TAA. (economist.com)
  • Since the binding of DNA by histones interferes with this access, cells have evolved specific mechanism to destabilize nucleosomes in chromosome regions that must be transcribed. (encyclopedia.com)
  • The DNA is tightly coiled many times around proteins called histones that support the chromosome structure. (conservapedia.com)
  • Un chromosome (du grec χρώμα, couleur et σώμα, corps, élément) est un élément microscopique constitué de molécules d'ADN et de protéines, les histones et les protéines non-histones. (dbpedia.org)
  • In the nuclear chromosomes of eukaryotes, the uncondensed DNA exists in a semi-ordered structure, where it is wrapped around histones (structural proteins), forming a composite material called chromatin. (wikiversity.org)
  • Most eukaryotic chromosomes include packaging proteins called histones which, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. (wikipedia.org)
  • The familiar X shape actually refers to 2 identical chromosomes referred to as sister chromatids. (conservapedia.com)
  • A connection is created by this crossover, plus linkages between sister chromatids along their lengths ( Fig. 1 B ). Crossovers/chiasmata occur in a strikingly nonrandomly distribution along the chromosomes (ref. 1 and Fig. 1 C and D ). (pnas.org)
  • Cohesion fulfils an important function during cell division as the newly copied chromosomes, the sister chromatids, have to stay together until the right moment of separation. (eurekalert.org)
  • Replicated chromosomes align on the equatorial plane during metaphase, sister chromatids disjoin during anaphase and cell division is completed in telophase, leaving two identical daughter cells that return to interphase. (els.net)
  • Sister chromatids are held together by cohesins to ensure the proper orientation of the chromosomes on the spindle and their separation at anaphase. (els.net)
  • Structural chromosome abnormalities occurring in germ cells may have similar effects. (greenfacts.org)
  • Early in embryonic development in females, one of the two X chromosomes is randomly and permanently inactivated in cells other than egg cells. (medlineplus.gov)
  • Because X-inactivation is random, in normal females the X chromosome inherited from the mother is active in some cells, and the X chromosome inherited from the father is active in other cells. (medlineplus.gov)
  • This condition is caused by the presence of an extra X chromosome and an extra Y chromosome in a male's cells. (medlineplus.gov)
  • People with ring chromosome 22 have one copy of this abnormal chromosome in some or all of their cells. (medlineplus.gov)
  • A rearrangement (translocation) of genetic material between chromosomes 9 and 22 causes a type of cancer of blood-forming cells called chronic myeloid leukemia. (medlineplus.gov)
  • The dual problem of how to store this large amount of genetic information but also to keep it accessible for use and for faithful maintenance, copying, and distribution to daughter cells during cell division , is solved by using proteins to package the DNA into chromosomes. (encyclopedia.com)
  • Each of these chromosome numbers is the so-called diploid number, i.e., the number found in the somatic (body) cells and in the germ cells that give rise to the gametes, or reproductive cells. (factmonster.com)
  • GENETIC diseases might one day be treated by adding an entirely new chromosome to people's cells. (newscientist.com)
  • In experiments on mice, Chromos has demonstrated that the bogus chromosomes are transmitted from mother cells to daughter cells during cell division and from one generation to the next as animals reproduce. (technologyreview.com)
  • As the embryo grows, complementary mutations in its cells may compensate for each other, or cells without chromosome defects may preferentially populate the embryo. (technologyreview.com)
  • The benefits of preimplantation screening are already hotly debated, since chromosome errors occur frequently in older women who may produce few eggs to begin with which stand a worse chance of successful impregnation following invasive biopsies to remove cells for genetic screening. (technologyreview.com)
  • The female has two X chromosomes, and all female egg cells normally carry a single X. The eggs fertilized by X-bearing sperm become females (XX), whereas those fertilized by Y-bearing sperm become males (XY). (britannica.com)
  • In any one kind of plant or animal, the chromosome count is usually constant in their cells. (everything2.com)
  • The cell skeleton, which distributes the chromosomes to the two daughter cells during cell division, attaches to the centromeres. (redorbit.com)
  • The Y chromosome spans more than 59 million building blocks of DNA and represents almost 2 percent of the total DNA in cells. (dailymail.co.uk)
  • Chromosomes are visible only during cell division, when the DNA is super coiled and condensed to facilitate distribution into daughter cells. (conservapedia.com)
  • At least twenty chromosome spreads will be prepared and chromosomes will be counted to determine the percentage of euploid cells. (nationaljewish.org)
  • Mouse ES cells need to be of a low passage number, should be mycoplasma-free, and a large percentage of them should be euploid, as determined by chromosome counting. (nationaljewish.org)
  • Along a given chromosome, events occur at different positions in different meiotic cells. (pnas.org)
  • If the chromatids come apart too early, there is a risk of the daughter cells getting the wrong number of chromosomes, something that is often observed in tumour cells. (eurekalert.org)
  • Human chromosomes are much bigger and more complex than proteins, but like proteins, they appear to fold and unfold in an orderly process as they carry out their functions in cells. (eurekalert.org)
  • Each time one of our cells divides the chromosomes condense and form distinct shapes that can be seen by a normal light microscope. (kickstarter.com)
  • As cells divide, chromosomes need to be replicated perfectly. (cnn.com)
  • Textbooks have often said that chromosomes were first observed in plant cells by a Swiss botanist named Karl Wilhelm von Nägeli in 1842. (yahoo.com)
  • Inside most of those cells are chromosomes, which are thread-like strands that contain hundreds, or even thousands, of genes . (kidshealth.org)
  • Cells of diploid daylilies contain 22 chromosomes (two sets). (daylilies.org)
  • Cells enter prophase I after DNA replication, although the chromosomes appear as single strands. (els.net)
  • Could the percentage of cells lacking a Y chromosome predict disease outcomes in men? (medicalnewstoday.com)
  • In females, usually one X chromosome is inactivated in each cell, but the 12 genes are so important that they escape inactivation, and XX cells, like XY cells, receive a double dose of the gene's products. (nytimes.com)
  • WEDNESDAY, Oct. 22, 2014 (HealthDay News) -- Elderly men who've lost the Y chromosome from their blood cells may be at increased risk for earlier death and death from cancer , a new study suggests. (medicinenet.com)
  • Men who had significant Y chromosome loss in their blood cells lived an average of 5.5 years less than those who did not have that chromosome loss. (medicinenet.com)
  • Y chromosome loss "is not very dangerous in a small fraction of blood cells, but becomes increasingly predictive of cancer as more cells lose their Y chromosome. (medicinenet.com)
  • It also reproduced, and subsequent cells carried the new chromosome forward. (cnn.com)
  • All cells in the human body, except red blood cells, contain chromosomes. (theregister.co.uk)
  • Some use the term chromosome in a wider sense, to refer to the individualized portions of chromatin in cells, either visible or not under light microscopy. (wikipedia.org)
  • Most chromosomes have the rough shape of an I when they condense prior to replication and are as bits of long invisible string when unwound. (conservapedia.com)
  • Chromosomes (shown in green) become visible in early prophase and continue to condense through late prophase. (els.net)
  • Homologues begin to pair in zygotene, with chiasmata (points of recombination or crossing over) becoming evident as chromosomes continue to condense during pachytene. (els.net)
  • By contrast, the new chromosome is a product of purposeful tinkering, but the yeast that carry it act like normal yeast. (usatoday.com)
  • The chromosome in question belongs to the humble species known as brewer's yeast, crucial for beer, bread and biotechnology. (usatoday.com)
  • In the end, all the yeast carried a bioengineered version of chromosome III. (usatoday.com)
  • Fission yeast cdc21+ belongs to a family of proteins involved in an early step of chromosome replication. (ebi.ac.uk)
  • THE science of synthetic biology took an important step forward this week with the announcement in Science , by a team from Jef Boeke's laboratory at Johns Hopkins University, in Baltimore, of the first completely synthetic yeast chromosome. (economist.com)
  • Although such genetic happenings are common on the Y chromosome, scientists have also identified regions which contain palindromic sequences which seem to help the Y chromosome retain its active functions. (brighthub.com)
  • Dr. Kaessmann's group, on the other hand, devised a quick method of fishing out Y chromosome genes by simply comparing the X and Y DNA of various species and assuming that any genetic sequences that did not match to the X must come from the Y. (nytimes.com)
  • The nucleotide sequences complexity in chromosome 3 of Caenorhabditis elegans ( C. elegans ) is studied. (hindawi.com)
  • In this paper, almost all nucleotide sequences that are located on chromosome 3 of C . elegans were analyzed and compared with random sequences. (hindawi.com)
  • Chromosome seven is the home of genes associated with cystic fibrosis, deafness, several cancers and a protein that resists cancer drugs. (wired.com)
  • A chromosome consists of a single double helix of DNA wrapped around a protein scaffold. (everything2.com)
  • In most individuals with 46,XX testicular disorder of sex development, the condition results from an abnormal exchange of genetic material between chromosomes (translocation). (medlineplus.gov)
  • 22q11.2 duplication is caused by an extra copy of some genetic material at position q11.2 on chromosome 22. (medlineplus.gov)
  • Scientists have long been fascinated by the way in which the duplicated chromosomes are separated before cell division so that exactly half the copied genetic material ends up in each daughter cell. (eurekalert.org)
  • Scientists have built a custom chromosome -- a package of genetic material assembled entirely from synthetic DNA. (voanews.com)
  • Over time, genes that were beneficial for males and harmful to (or had no effect on) females either developed on the Y chromosome or were acquired through the process of translocation . (wikipedia.org)
  • for example, in the condensation of chromosomes at metaphase. (encyclopedia.com)
  • Cell division is arrested during metaphase, when the chromosome material is condensed. (conservapedia.com)
  • During metaphase the X-shaped structure is called a metaphase chromosome, which is highly condensed and thus easiest to distinguish and study. (wikipedia.org)
  • Dr. Kaessmann calculates that the Y chromosome originated 181 million years ago, after the duck-billed platypus split off from other mammals but before the marsupials did so. (nytimes.com)
  • Female (XX) mammals inherit one X chromosome from each parent, but males (XY) receive an X from their mother and a Y sex chromosome from their father. (psychologytoday.com)
  • Most therian mammals have only one pair of sex chromosomes in each cell. (wikipedia.org)
  • Female mammals get an X chromosome from each parent, but males receive an X from their mother and a Y sex chromosome from their father. (psychologytoday.com)
  • Different kinds of organisms have different numbers of chromosomes. (conservapedia.com)
  • for example mitochondria in most eukaryotes and chloroplasts in plants have their own small chromosome in addition to the nuclear chromosomes. (wikiversity.org)
  • An artist's rendering of a new "designer chromosome" shows red and blue pins and white diamonds at the spots where scientists engineered changes to the original chromosome. (usatoday.com)
  • Authoritative and cutting-edge, Mammalian Chromosome Engineering: Methods and Protocols serves as a bench-side resource for current protocols and aims to help scientists to explore the many prospects for future research and vital applications. (springer.com)
  • Lately, scientists have been wondering whether they can fool the machinery of the cell by inserting a synthetic 47th chromosome furnished with genes of their own choosing. (technologyreview.com)
  • It has also been shown that regions of the Y chromosome are constantly being lost by either deletions or recombination which might - so some scientists believe - eventually wipe out the male species from the human race. (brighthub.com)
  • Some scientists believe that the loss of the Y chromosome could help explain this gender difference. (medicalnewstoday.com)
  • Scientists have built a designer chromosome and inserted it into a cell, geneticist Jef Boeke from New York University announced this week . (cnn.com)
  • Boys and men with 48,XXXY syndrome have the usual single Y chromosome plus three copies of the X chromosome, for a total of 48 chromosomes in each cell. (medlineplus.gov)
  • Having extra copies of multiple genes on the X chromosome affects many aspects of development, including sexual development before birth and at puberty. (medlineplus.gov)
  • The duplication affects one of the two copies of chromosome 22 in each cell. (medlineplus.gov)
  • Assuming that the data is about 100 megabases long, the Perl programmer can see that the subroutine "get_chromosome" is collecting 100 megabases of DNA and then "returning" it, which means that copies of those 100 megabases are being made. (perl.com)
  • Preimplantation genetic screening (PGS) usually involves either polymerase chain reaction (PCR), which detects genetic disorders by amplifying a specific chunk of mutated DNA, or fluorescent in-situ hybridization (FISH), which allows chromosomes to be checked for structural flaws against normal chromosomes but cannot screen all chromosomes simultaneously. (technologyreview.com)
  • The evolution of the mammalian X and Y sex-determining chromosomes from ancestral chromosomes is thought to have occurred through a rapid loss of genes from the Y chromosome. (nature.com)
  • It turns out that chromosome 2, which is unique to the human lineage of evolution, emerged as a result of the head-to-head fusion of two ancestral chromosomes that remain separate in other primates. (pbs.org)
  • Caption: In 2000, the genomes of the two chromosomes possessed by V. cholerae were sequenced. (nsf.gov)
  • In my previous article, A Chromosome at a Time with Perl, Part I , I showed you some programming "tricks" that help you avoid the trap of using up all your main memory when coding for very long strings, such as chromosomes and entire genomes. (perl.com)
  • The male sex chromosome has long been called our genetic junkyard, a clutter of meaningless DNA surrounding a handful of genes--and those only good for making more men. (sciencemag.org)
  • A broader definition of "chromosome" also includes the DNA-bound proteins which serve to package and manage the DNA. (wikiversity.org)
  • Chromosome, Eukaryotic Living organisms are divided into two broad categories based upon certain attributes of cell structure. (bookrags.com)
  • Chromosomes appear microscopically as a linear arrangement of genes, the factors that determine the inherited characteristics of all living organisms. (factmonster.com)
  • These organisms gather all the chromosome ends against the nuclear envelope into one big cluster called a bouquet or into a bunch of smaller clusters called aggregates, and this brings the chromosome ends into proximity with each other," Hawley says. (medicalnewstoday.com)
  • Chromosomes vary extensively between different organisms. (wikiversity.org)
  • The SNP array can identify variations in short pieces of DNA, while the BAC array can analyze larger chromosome chunks for structural errors. (technologyreview.com)
  • Kelly experienced changes in his gut microbiome, his cognitive abilities slowed down, certain genes would turn off and on, and his chromosome s experienced structural changes. (dictionary.com)
  • The majority of recognizable genes for essential cell functions (such as DNA replication, transcription, translation, etc.) and pathogenicity (such as toxin, surface antigens, and adhesion) are located on the large chromosome. (nsf.gov)
  • Chromosome mechanics describes the processes of chromosome replication and interactions during somatic cell division and gametogenesis. (els.net)
  • This model encounters a disabling difficulty: namely, how to account for the spread in a population of a chromosome rearrangement after it first arises as a mutation in a single individual. (pnas.org)
  • Defects in chromosomes or genes may cause changes in certain body processes or functions. (webmd.com)
  • This means that many embryos must go on to develop into healthy babies even though their chromosomes have defects at this stage. (technologyreview.com)
  • Defects in DNA repair mechanisms can also result in chromosome damage or breaking which will negatively impact the process of cell division. (els.net)
  • The "suppressed-recombination" model of speciation points out that chromosome rearrangements act as a genetic filter between populations. (pnas.org)
  • The phases through which chromosomes replicate, divide, shuffle, and recombine are imperfect, as DNA is subject to random mutations. (pbs.org)
  • Mutations associated with the rearranged chromosomes cannot flow from one to another population, whereas genetic exchange will freely occur between colinear chromosomes. (pnas.org)
  • Mutations adaptive to local conditions will, therefore, accumulate differentially in the protected chromosome regions so that parapatric or partially sympatric populations will genetically differentiate, eventually evolving into different species. (pnas.org)
  • Females have two X chromosomes, while males have one X and one Y chromosome. (medlineplus.gov)
  • X-inactivation ensures that females, like males, have one functional copy of the X chromosome in each body cell. (medlineplus.gov)
  • Females have two X chromosome s, males have X and Y chromosome s. (everything2.com)
  • Females have a pair of X chromosomes (46, XX), whereas males have one X and one Y chromosomes (46, XY). (nih.gov)
  • Females have two X chromosomes, while men have one X and one Y. Among other things, the Y chromosome contains code that triggers the development of the testis. (medicalnewstoday.com)
  • Since females have two X chromosomes, one may be expressed, or manifest in the phenotype, and the other may be silenced. (psychologytoday.com)
  • We can further divide the chromosomes using special stains that produce stripes known as a banding pattern. (nih.gov)
  • As noted above, the chromosome number varies in different species. (conservapedia.com)
  • Why different species have dissimilar sets of chromosomes? (redorbit.com)
  • Why the differentiated species often conserve apparently identical chromosome complements? (redorbit.com)
  • Furthermore, why, while chromosome rearrangements can considerably change the course of species evolution, certain variation among individuals and populations of some species persists indefinitely? (redorbit.com)
  • But an analysis in 2012 showed that the rhesus monkey's Y chromosome had essentially the same number of genes as the human Y. This suggested that the Y had stabilized and ceased to lose genes for the last 25 million years, the interval since the two species diverged from a common ancestor. (nytimes.com)
  • Each chromosome is a very long molecule, so it needs to be wrapped tightly around proteins for efficient packaging. (nih.gov)
  • First, the banding (or dye pattern) of human chromosome 2 closely matches that of two separate chromosomes found in apes (chimp chromosome 2 and an extra chromosome that does not match any other human chromosome). (pbs.org)
  • Five of the new Y genes are found on the X chromosome and are expressed in many tissues, where they play an important role in cell "housekeeping," such as ensuring normal ribosome function. (sciencemag.org)
  • While diseases such as color-blindness and hemophilia have long been understood to be X-linked, biologists and behavioral geneticists now know that important brain functions and conditions, from intelligence to autism , may be up-regulated or down-regulated by genes found on the X chromosome. (psychologytoday.com)
  • Chromosome Mapping Also known as cytogenetic mapping or genetic mapping, chromosome mapping is a technique used to locate particular characteristics (coded for by specific genes) on specific chromosom. (bookrags.com)
  • The Y chromosome contains around 70 to 200 genes that are mostly involved in sex determination and the development of the male reproductive system and sexual characteristics. (brighthub.com)
  • One result of the new study was the observation that, at least during the interphase state the Rice team primarily studied, chromosome domains take on the characteristics of liquid crystals. (eurekalert.org)
  • X and Y chromosomes determine not only the sex of an individual, but many broad characteristics as well. (psychologytoday.com)
  • Study on fractal analysis of multigenome of C . elegans has shown that chromosome 3 is the one with multifractal characteristics higher than the others, the less multifractal appears to be the chromosome sexual X [ 6 ]. (hindawi.com)
  • Thus, chromosome 3 of C . elegans has been carefully studied because its unsymmetrical and inhomogeneous statistical characteristics. (hindawi.com)
  • The Hospital for Sick Children in Toronto published its version of chromosome seven in April. (wired.com)