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)
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)
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.
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.
A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.
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.
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.
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).
Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.
The human female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in humans.
The human male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans.
The mechanisms by which the SEX of an individual's GONADS are fixed.
Mapping of the KARYOTYPE of a cell.
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.
The alignment of CHROMOSOMES at homologous sequences.
Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.
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.
A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.
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.
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.
The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
Genes that are located on the Y CHROMOSOME.
A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.
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.
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).
Genes that are located on the X CHROMOSOME.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
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.
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 E 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)
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.
A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.
A small aquatic oviparous mammal of the order Monotremata found in Australia and Tasmania.
Actual loss of portion of a chromosome.
Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.
Structures within the CELL NUCLEUS of insect cells containing DNA.
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 specific pair GROUP C CHROMSOMES of the human chromosome classification.
A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.
A specific pair of GROUP C CHROMSOMES of the human chromosome classification.
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)
A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.
Structures within the nucleus of fungal cells consisting of or containing DNA, which carry genetic information essential to the cell.
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.).
Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of MAMMALS.
A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.
Abnormal genetic constitution in males characterized by an extra Y chromosome.
A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.
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.
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 B CHROMOSOMES of the human chromosome classification.
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.
The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.
The stage in the first meiotic prophase, following ZYGOTENE STAGE, when CROSSING OVER between homologous CHROMOSOMES begins.
A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
Structures which are contained in or part of CHROMOSOMES.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
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.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
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 F CHROMOSOMES of the human chromosome classification.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
One of the two pairs of human chromosomes in the group B class (CHROMOSOMES, HUMAN, 4-5).
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 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.
A plant genus of the family Caricaceae, order Violales, subclass Dilleniidae, class Magnoliopsida. It is the source of edible fruit and PAPAIN.
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 D CHROMOSOMES of the human chromosome classification.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The short, submetacentric human chromosomes, called group E in the human chromosome classification. This group consists of chromosome pairs 16, 17, and 18.
A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.
A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.
Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.
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.
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.
The passage of viable bacteria from the GASTROINTESTINAL TRACT to extra-intestinal sites, such as the mesenteric lymph node complex, liver, spleen, kidney, and blood. Factors that promote bacterial translocation include overgrowth with gram-negative enteric bacilli, impaired host immune defenses, and injury to the INTESTINAL MUCOSA resulting in increased intestinal permeability. Bacterial translocation from the lung to the circulation is also possible and sometimes accompanies MECHANICAL VENTILATION.
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.
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.
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 process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
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 possession of a third chromosome of any one type in an otherwise diploid cell.
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 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)
Validation of the SEX of an individual by inspection of the GONADS and/or by genetic tests.
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 large, submetacentric human chromosomes, called group B in the human chromosome classification. This group consists of chromosome pairs 4 and 5.
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.
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.
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.
Aberrant chromosomes with no ends, i.e., circular.
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 process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
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.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
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.
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 outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
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).
Congenital conditions of atypical sexual development associated with abnormal sex chromosome constitutions including MONOSOMY; TRISOMY; and MOSAICISM.
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 family of flightless, running BIRDS, in the order Casuariiformes. The emu is the only surviving member of the family. They naturally inhabit forests, open plains, and grasslands in Australia.
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 chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.
An infraclass of MAMMALS, also called Metatheria, where the young are born at an early stage of development and continue to develop in a pouch (marsupium). In contrast to Eutheria (placentals), marsupials have an incomplete PLACENTA.
The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
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.
The relationships of groups of organisms as reflected by their genetic makeup.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
The totality of characteristics of reproductive structure, functions, PHENOTYPE, and GENOTYPE, differentiating the MALE from the FEMALE organism.
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 short, metacentric human chromosomes, called group F in the human chromosome classification. This group consists of chromosome pairs 19 and 20.
An aberration in which an extra chromosome or a chromosomal segment is made.
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).
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 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.
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.
Group of fish under the superorder Acanthopterygii, separate from the PERCIFORMES, which includes swamp eels, mullets, sticklebacks, seahorses, spiny eels, rainbowfishes, and KILLIFISHES. The name is derived from the six taxa which comprise the group. (From http://www.nanfa.org/articles/Elassoma/elassoma.htm, 8/4/2000)
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.
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.
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.
Established cell cultures that have the potential to propagate indefinitely.
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.
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.
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 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.
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.
The condition in which one chromosome of a pair is missing. In a normally diploid cell it is represented symbolically as 2N-1.
The number of males per 100 females.
The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.
Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.
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)
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.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
A genus, Muntiacus, of the deer family (Cervidae) comprising six species living in China, Tibet, Nepal, India, the Malay Peninsula, and neighboring island countries. They are usually found in forests and areas of dense vegetation, usually not far from water. They emit a deep barklike sound which gives them the name "barking deer." If they sense a predator they will "bark" for an hour or more. They are hunted for their meat and skins; they thrive in captivity and are found in many zoos. The Indian muntjac is believed to have the lowest chromosome number in mammals and cell lines derived from them figure widely in chromosome and DNA studies. (From Walker's Mammals of the World, 5th ed., p1366)
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).
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.
An order of fresh water fish with 18 families and over 1600 species. The order includes CHARACINS, hatchetfish, piranhas, and TETRAS.
Genotypic differences observed among individuals in a population.
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.
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.
An individual having different alleles at one or more loci regarding a specific character.
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.
Gated transport mechanisms by which proteins or RNA are moved across the NUCLEAR MEMBRANE.
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.
The prophase of the first division of MEIOSIS (in which homologous CHROMOSOME SEGREGATION occurs). It is divided into five stages: leptonema, zygonema, PACHYNEMA, diplonema, and diakinesis.
The total relative probability, expressed on a logarithmic scale, that a linkage relationship exists among selected loci. Lod is an acronym for "logarithmic odds."
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.
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.
An order of the class Insecta. Wings, when present, number two and distinguish Diptera from other so-called flies, while the halteres, or reduced hindwings, separate Diptera from other insects with one pair of wings. The order includes the families Calliphoridae, Oestridae, Phoridae, SARCOPHAGIDAE, Scatophagidae, Sciaridae, SIMULIIDAE, Tabanidae, Therevidae, Trypetidae, CERATOPOGONIDAE; CHIRONOMIDAE; CULICIDAE; DROSOPHILIDAE; GLOSSINIDAE; MUSCIDAE; TEPHRITIDAE; and PSYCHODIDAE. The larval form of Diptera species are called maggots (see LARVA).
Mapping of the linear order of genes on a chromosome with units indicating their distances by using methods other than genetic recombination. These methods include nucleotide sequencing, overlapping deletions in polytene chromosomes, and electron micrography of heteroduplex DNA. (From King & Stansfield, A Dictionary of Genetics, 5th ed)
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.
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.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.
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 functional hereditary units of INSECTS.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Methods for controlling genetic SEX of offspring.
The three-part structure of ribbon-like proteinaceous material that serves to align and join the paired homologous CHROMOSOMES. It is formed during the ZYGOTENE STAGE of the first meiotic division. It is a prerequisite for CROSSING OVER.
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.
The chromosomal constitution of cells, in which each type of CHROMOSOME is represented once. Symbol: N.
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.
Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.
An oviparous burrowing mammal of the order Monotremata native to Australia, Tasmania, and New Guinea. It has hair mingled with spines on the upper part of the body and is adapted for feeding on ants.
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.
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.
Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.
The locations in specific DNA sequences where CHROMOSOME BREAKS have occurred.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
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.
The chromosomal constitution of a cell containing multiples of the normal number of CHROMOSOMES; includes triploidy (symbol: 3N), tetraploidy (symbol: 4N), etc.
The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.
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 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.
Genetic loci associated with a QUANTITATIVE TRAIT.
Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.
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.
A plant genus of the family ROSACEAE known for the edible fruit.
A genus of large OPOSSUMS in the family Didelphidae, found in the Americas. The species Didelphis virginiana is prominent in North America.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
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.
An increased tendency to acquire CHROMOSOME ABERRATIONS when various processes involved in chromosome replication, repair, or segregation are dysfunctional.
The portion of chromosome material that remains condensed and is transcriptionally inactive during INTERPHASE.
Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.
The functional hereditary units of PLANTS.
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.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Susceptibility of chromosomes to breakage leading to translocation; CHROMOSOME INVERSION; SEQUENCE DELETION; or other CHROMOSOME BREAKAGE related aberrations.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
"Widespread Translocation from Autosomes to Sex Chromosomes Preserves Genetic Variability in an Endangered Lark". Journal of ... The adult sex ratio is unbalanced, with a high proportion of the population being male. The Raso lark feeds by digging in the ... Both sexes also feed on grass seeds, and insects such as butterflies, moths and grasshoppers. Food and water for the Raso lark ... The tiny population size, which fluctuates from ~200-1,000 birds, coupled with the highly skewed sex ratio (around two males to ...
Due to an X-autosome translocation, S. delicatus has an XY1Y2 sex chromosome system, rare in mammals. During meiotic prophase, ... Lanzone, C.; Rodríguez, D.; Cuello, P.; Albanese, S.; Ojeda, A.; Chillo, V.; Martí, D. A. (2011). "XY1Y2 chromosome system in ... a male's X and two Y chromosomes form a trivalent. The female value of 18 is the lowest diploid number of any species in the ... it appears that major chromosome restructuring occurred during the evolution of the Andalgalomys-Salinomys clade. While not ...
"Chromosome landmarks and autosome-sex chromosome translocations in Rumex hastatulus, a plant with XX/XY1Y2 sex chromosome ... Due to their complex chromosomal makeup their sex is determined by the ratio of x and y chromosomes. This gender determination ... in flowering plants leading to a lot of research being done into environmental and genetic factors in that determine the sex. " ... system". Chromosome Research. 23 (2): 187-197. doi:10.1007/s10577-014-9446-4. ISSN 0967-3849. PMC 4430600. PMID 25394583.. ...
It is also hypothesized that this turtle's sex chromosomes were formed from the translocation of an ancestral Y microchromosome ... A new piece in the puzzle of sex chromosome evolution in turtles". Chromosome Research. 16 (6): 815-825. doi:10.1007/s10577-008 ... "An XX/XY heteromorphic sex chromosome system in the Australian chelid turtle Emydura macquarii: ... E. macquarii uses the XY sex-determination system, making it one of the few turtle species that has a genetic SDM. The X and Y ...
Studies indicate that the X chromosome can determine the levels of sex hormones. A study has shown an association between ... XXY males with SLE have an abnormal X-Y translocation resulting in the partial triplication of the PAR1 gene region.[104] ... The X chromosome carries immunological related genes, which can mutate and contribute to the onset of SLE. The Y chromosome has ... Sex. SLE, like many autoimmune diseases, affects females more frequently than males, at a rate of about 9 to 1.[5][95] ...
In the wake of the establishment of the normal number of human chromosomes, 47,XYY was the last of the common sex chromosome ... 9 XY familial balanced autosomal chromosome translocation control boys: average full-scale IQ=119.33 (range=103-137). CS1 maint ... Harper, Peter S. (2006). "The sex chromosomes". First years of human chromosomes : the beginnings of human cytogenetics. ... This tall (that chromosome), intelligent (that chromosome again), functionally nonviolent (that chromosome still again) fellow ...
An autosome is any chromosome that is not a sex chromosome (an allosome). The members of an autosome pair in a diploid cell ... Partial aneuploidy can also occur as a result of unbalanced translocations during meiosis. Deletions of part of a chromosome ... For example, the SRY gene on the Y chromosome encodes the transcription factor TDF and is vital for male sex determination ... Klar, Amar J S (2002). "The chromosome 1;11 translocation provides the best evidence supporting genetic etiology for ...
... provided a new concept of Chromosomal translocation of sex-determining region from Y chromosome to X chromosomes causing sex ... During the 1970s, while studying the evolution of sex chromosome in a species of an Indian snake, the banded krait, Singh and ... In 1982, Singh and his colleagues discovered that a tiny portion of the short arm of sex-determining Y chromosome was necessary ... Singh, L.; Sharma, T.; Ray-Chaudhuri, S.P. (1970). "Multiple sex chromosomes in the common krait, Bungarus caeruleus Schneider ...
... sex chromosome aberrations MeSH C23.550.210.815.970 - xyy karyotype MeSH C23.550.210.870 - translocation, genetic MeSH C23.550. ... chromosome instability MeSH C23.550.210.110.180 - chromosome fragility MeSH C23.550.210.170 - chromosome breakage MeSH C23.550. ... 210.175 - chromosome deletion MeSH C23.550.210.420 - inversion, chromosome MeSH C23.550.210.430 - isochromosomes MeSH C23.550. ... 210.870.680 - philadelphia chromosome MeSH C23.550.260.095 - asphyxia MeSH C23.550.260.159 - brain death MeSH C23.550.260.224 ...
758.6 Gonadal dysgenesis Turner syndrome XO syndrome 758.7 Klinefelter syndrome 758.8 Other conditions due to sex chromosome ... syndrome 758.33 Other microdeletions Miller-Dieker syndrome Smith-Magenis syndrome 758.4 Balanced autosomal translocation in ... anomalies Snyder-Robinson syndrome (SRS) 758.9 Conditions due to anomaly of unspecified chromosome 759 Other and unspecified ... and epispadias 752.61 Hypospadias 752.62 Epispadias 752.63 Congenital chordee 752.64 Micropenis 752.7 Indeterminate sex and ...
... sex chromosome aberrations MeSH G13.920.590.175.815.970 - xyy karyotype MeSH G13.920.590.175.870 - translocation, genetic MeSH ... chromosome fragility MeSH G13.920.590.175.175 - chromosome breakage MeSH G13.920.590.175.177 - chromosome deletion MeSH G13.920 ... chromosome-defective MeSH G13.920.590.175.595 - mosaicism MeSH G13.920.590.175.760 - ring chromosomes MeSH G13.920.590.175.815 ... MeSH G13.330.159 - gene flow MeSH G13.330.320 - genetic drift MeSH G13.370.180 - chromosome instability MeSH G13.370.180.180 - ...
... the sex chromosomes. Although the XX/XY sex chromosome system is the most common among eutherian species, it is not universal. ... In some species X-autosomal translocations result in the appearance of "additional Y" chromosomes (for example, XX/XY1Y2Y3 ... Chromosome banding has been a reliable indicator of chromosome homology overall, i.e. that the chromosome identified on the ... In addition to sorting, microdissection of chromosomes and chromosome regions was also used to obtain probes for chromosome ...
46,XX testicular disorders of sex development X chromosome, for other conditions related to the X chromosome. For a condition ... The tip of the Y chromosome contains the SRY gene and, during recombination, a translocation occurs in which the SRY gene ... The SRY gene, normally found on the Y chromosome, plays an important role in sex determination by initiating testicular ... The X chromosome with the SRY gene is preferentially chosen to be the active X chromosome 90% of the time, which explains ...
Before Y chromosome[edit]. Many ectothermic vertebrates have no sex chromosomes. If they have different sexes, sex is ... females either developed on the Y chromosome or were acquired through the process of translocation.[17] ... ZW chromosomes[edit]. Other organisms have mirror image sex chromosomes: where the homogeneous sex is the male, said to have ... For example, female birds, snakes, and butterflies have ZW sex chromosomes, and males have ZZ sex chromosomes.[citation needed] ...
Chromosomal translocations between the sex chromosomes can also result in a number of genetic conditions, such as XX male ... The designation t(A;B)(p1;q2) is used to denote a translocation between chromosome A and chromosome B. The information in the ... In genetics, chromosome translocation is a phenomenon that results in unusual rearrangement of chromosomes. This includes ... Reciprocal translocation is a chromosome abnormality caused by exchange of parts between non-homologous chromosomes. Two ...
... the condition results from an abnormal exchange of genetic material between chromosomes (translocation). This exchange occurs ... Genes that are carried by either sex chromosome are said to be sex linked. Sex linked diseases are passed down through families ... Angiosperms with separate sexes (dioecious) may use sex chromosomes or environmental flowers for sex determination. Cytogenetic ... If it occurs after sex chromosomes are established, dosage should stay consistent between the sex chromosomes and autosomes, ...
... often due to translocation of the SRY gene to the X chromosome) or XY gonadal dysgenesis in people who are externally female ( ... In humans, most mammals, and some other species, two of the chromosomes, called the X chromosome and Y chromosome, code for sex ... the sex of an individual is determined by a pair of sex chromosomes. Females typically have two of the same kind of sex ... sex is determined by presence of the Y chromosome. "Female" is the default sex, due to the absence of the Y chromosome.[5] In ...
Translocations: A portion of one chromosome has been transferred to another chromosome. There are two main types of ... where only part of a chromosome is missing or added. Aneuploidy can occur with sex chromosomes or autosomes. An example of ... Reciprocal translocation: Segments from two different chromosomes have been exchanged. Robertsonian translocation: An entire ... An example of monosomy in humans is Turner syndrome, where the individual is born with only one sex chromosome, an X. Exposure ...
Before Y chromosomeEdit. Many ectothermic vertebrates have no sex chromosomes. If they have different sexes, sex is determined ... females either developed on the Y chromosome or were acquired through the process of translocation.[13] ... pairs of XY sex chromosomes, each pair consisting of sex chromosomes with homologous regions. The chromosomes of neighboring ... ZW chromosomesEdit. Other organisms have mirror image sex chromosomes: where the homogeneous sex is the male, said to have two ...
Translocations: A portion of one chromosome is transferred to another chromosome. There are two main types of translocations: * ... An example of monosomy is Turner syndrome, where the individual is born with only one sex chromosome, an X. ... Reciprocal translocation: Segments from two different chromosomes have been exchanged.. *Robertsonian translocation: An entire ... It can be from an atypical number of chromosomes or a structural abnormality in one or more chromosomes. Chromosome mutation ...
Robertsonian translocations are variations in the numbers of chromosomes that arise from either: the fusion of two acrocentric ... Therefore, it is not a problem related to sexual development, nor with the sex chromosomes. Haldane proposed that the stability ... In certain cases, complete translocations exist that involve more than two chromosomes, so that the meiosis of the hybrids is ... In addition, interactions between chromosomes are detected so that certain combinations of the chromosomes have a multiplying ...
... pioneer on sex chromosome anomalies Herschel L. Roman (1914-1989), US geneticist, innovated in analysis in maize and budding ... US cancer cytogeneticist who found Ph chromosome due to translocation Peter T. Rowley (1929-2006), US internist and geneticist ... discovered XY and XX sex chromosomes Øjvind Winge (1886-1964), Danish biologist and pioneer in yeast genetics Chester B. ... pioneer in chromosome mechanics Paul Nurse (born 1949), UK biochemist, Nobel Prize for work on CDK, a key regulator of the cell ...
The content of a chromosome would be changed mainly by mutation after duplication of the chromosome and translocation with ... ISBN 0-471-26821-6. Ohno S (1967). Sex Chromosomes and sex-linked genes. Berlin:Springer-Verlag. Ohno S (1970). Evolution by ... That is, nearly all mammalian species have conserved the X chromosome from their primordial X chromosome of a common ancestor. ... other chromosomes. However, in mammals, since the chromosomal sex-determination mechanism would have been established in their ...
Both Robertsonian translocations (fusions of the long arm of one chromosome with the long arm of another and the short arm of ... The autosomes (non-sex chromosomes) of the 2n = 34 karyotype all have two major arms, but the 2n = 40-42 karyotypes include ... The number of chromosomes varies from 34 to 54. The species was first described in 1891 by Joel Asaph Allen and thereafter a ... Both T. bolivaris and H. alfaroi have more chromosomes and arms, at 2n = 58, FN = 80 and 2n = 60-62, FN = 100-104 respectively ...
... encoded by the sex-determining region SRY of the Y chromosome) activates SOX-9 activity by binding to an enhancer sequence ... Deletions, disruptions by translocation breakpoints and a single point mutation of highly conserved non-coding elements located ... "Entrez Gene: SOX9 SRY (sex determining region Y)-box 9 (campomelic dysplasia, autosomal sex-reversal)". Kumar, Vinay; Abbas, ... December 1994). "Autosomal sex reversal and campomelic dysplasia are caused by mutations in and around the SRY-related gene ...
So, in normal diploid organisms, autosomal chromosomes are present in two copies. There may, or may not, be sex chromosomes. ... including chromosome breakage, loss, duplication, translocation or inverted segments. A range of different chromosome ... The typical human karyotypes contain 22 pairs of autosomal chromosomes and one pair of sex chromosomes (allosomes). The most ... This would give rise to a chromosome abnormality such as an extra chromosome or one or more chromosomes lost. Abnormalities in ...
The loss of the Y chromosome can occur from deletions, translocations, or migration failure of paired chromosomes during cell ... gonadal dysgenesis is a sex development disorder associated with sex chromosome aneuploidy and mosaicism of the Y chromosome. ... Biason-Lauber A (2006). The Battle of the Sexes: Human Sex Development and Its Disorders in Molecular Mechanisms of Cell ... Bashamboo A, McElreavey K (2015). "Human sex-determination and disorders of sex-development (DSD)". Seminars in Cell & ...
Fragile X syndrome was first described in 1943 by Martin and Bell, studying persons with family history of sex-linked "mental ... This disorder usually results from an extra chromosome 21, although in uncommon instances it is related to other chromosomal ... abnormalities such as translocation of the genetic material. It is characterized by short stature, epicanthal (eyelid) folds, ... Martin JP, Bell J (July 1943). "A pedigree of mental defect showing sex-linkage". Journal of Neurology and Psychiatry. 6 (3-4 ...
... sex chromosome(s)). Certain genetic traits are linked to a person's sex and are passed on through the sex chromosomes. The ... Some chromosome abnormalities do not cause disease in carriers, such as translocations, or chromosomal inversions, although ... sex determination Non-disjunction Sex-determination system XY sex-determination system X-chromosome X-inactivation Y-chromosome ... and two sex chromosomes. This gives 46 chromosomes in total. Other organisms have more than two copies of their chromosome ...
This includes the embryological development of the primary male sex organs, and the development of male secondary sex ... In males, certain Y chromosome genes, particularly SRY, control development of the male phenotype, including conversion of the ... nuclear translocation of androgen receptor complex with beta-catenin and T-cell factor 4 may bypass canonical Wnt signaling to ... In males, the sex cords fully invade the developing gonads.. Androgen production[edit]. The mesoderm-derived epithelial cells ...
Autosome/Sex chromosome (or allosome or heterosome). *Macrochromosome/Microchromosome. *Circular chromosome/Linear chromosome ... 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.. ...
Autosome/Sex chromosome (or allosome or heterosome). *Macrochromosome/Microchromosome. *Circular chromosome/Linear chromosome ... 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 ...
Autosome/Sex chromosome (or allosome or heterosome). *Macrochromosome/Microchromosome. *Circular chromosome/Linear chromosome ... The Wages of Sin: Sex and Disease, Past and Present. University of Chicago Press, 2000, p. 106. *For the obituary, see J.F.C. " ... Fausto-Sterling, Anne (2000). Sexing the body : gender politics and the construction of sexuality (1. ed., [Nachdr.] ed.). New ... Hiort, O. (2014). Understanding differences and disorders of sex development (DSD). Basel: Karger. ISBN 9783318025583.. .mw- ...
2008). "True hermaphroditism with XX/XY sex chromosome mosaicism: Report of a case". Clinical Genetics. 10 (5): 265-72. doi: ... Translocations. Leukemia/lymphoma. Lymphoid. *Burkitt's lymphoma t(8 MYC;14 IGH). *Follicular lymphoma t(14 IGH;18 BCL2) ... 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 ...
XX male syndrome/46,XX testicular disorders of sex development. *Marker chromosome ... Translocations. Leukemia/lymphoma. Lymphoid. *Burkitt's lymphoma t(8 MYC;14 IGH). *Follicular lymphoma t(14 IGH;18 BCL2) ... "OMIM Entry - # 158170 - CHROMOSOME 9p DELETION SYNDROME". www.omim.org. Retrieved 2017-03-10.. ... of a portion of chromosome 9. Symptoms include microgenitalia, intellectual disability with microcephaly and dysmorphic ...
She discovered that the affected children had unbalanced translocation between chromosome 11 and 21 which they had inherited ... XX male syndrome/46,XX testicular disorders of sex development. *Marker chromosome ... European Chromosome 11 Network - Support group for patients with chromosome 11 disorders, their families and relatives ... Ring chromosome 11- in this case genetic material from both long and short arm of the chromosome get deleted, and the remaining ...
A translocation between chromosomes 4 and 11 occurs in about 4% of cases and is most common in infants under 12 months. ... Sex. Male. Female Race. Black. Caucasian Organomegaly. Present. Absent Mediastinal mass. Present. Absent ... These changes include chromosomal translocations, intrachromosomal rearrangements, changes in the number of chromosomes in ... Gaining at least five additional chromosomes, called high hyperdiploidy, occurs more commonly. Less often, chromosomes are lost ...
... the product of a putative oncogene activated by chromosome translocations often found in follicular lymphoma. Unlike other ... Furthermore, sex targeted cell death leads to different neuronal innervation of specific organs in males and females. In ... 3.0.co;2-2. Zup, SL (2003). "Overexpression of bcl-2 reduces sex differences in neuron number in the brain and spinal cord". ... Giebultowicz, JM (1984). "Sexual differentiation in the terminal ganglion of the moth Manduca sexta: role of sex-specific ...
"Sex chromosomes and sex-linked inheritance". An Introduction to Genetic Analysis (7th ed.). New York: W.H. Freeman. ISBN 978-0- ... or the accidental exchange of whole parts of sequences between different chromosomes (chromosomal translocation). ... Many species have so-called sex chromosomes that determine the gender of each organism.[54] In humans and many other animals, ... In evolution, this chromosome has lost most of its content and also most of its genes, while the X chromosome is similar to the ...
A well-known example of this is the Philadelphia chromosome, or translocation of chromosomes 9 and 22, which occurs in chronic ... Hormones are important agents in sex-related cancers, such as cancer of the breast, endometrium, prostate, ovary and testis and ... The gain or loss of an entire chromosome can occur through errors in mitosis. More common are mutations, which are changes in ... Large-scale mutations involve the deletion or gain of a portion of a chromosome. Genomic amplification occurs when a cell gains ...
XX male syndrome/46,XX testicular disorders of sex development. *Marker chromosome ... Translocations. Leukemia/lymphoma. Lymphoid. *Burkitt's lymphoma t(8 MYC;14 IGH). *Follicular lymphoma t(14 IGH;18 BCL2) ... The sex ratio of patients with congenital malformations Congenital anomaly. Sex ratio, ♂♂:♀♀ ... Following studies showed elevated risks for other tumors and congenital malformations of the sex organs for both sexes. ...
... more chromosome breaks and translocations[19] and extensive deletions.[20] These DNA damages, chromosome aberrations and ... but the sex organs of individuals with this form of TTD often produce no hormones, a condition known as hypogonadism.[62] ... Variegated translocation mosaicism". Cytogenetics and Cell Genetics. 30 (2): 92-107. doi:10.1159/000131596. PMID 7273860.. ... Mouse cells deficient for maturation of prelamin A show increased DNA damage and chromosome aberrations and have increased ...
... is found on chromosome 14, and the loci containing lambda and kappa light chain genes ([email protected] and [email protected]) are found on chromosomes ... and class switch recombination in chromosomal translocations". DNA Repair (Amst.). 5 (9-10): 1234-1245. doi:10.1016/j.dnarep. ... "Class switching and Myc translocation: how does DNA break?". Nat. Immunol. 5 (11): 1101-1103. doi:10.1038/ni1104-1101. PMC ... region that encodes an antibody is large and contains several distinct gene loci for each domain of the antibody-the chromosome ...
All of subgroup 2 is organized into a head to tail cluster of chromosomes on chromosome 17q24. Genes in this second subgroup ... The predicted translocation pathway in BtuCD is open to the periplasm and closed at the cytoplasmic side of the membrane while ... 3.A.1.206 The a-Factor Sex Pheromone Exporter (STE) Family (ABCB) 3.A.1.208 The Drug Conjugate Transporter (DCT) Family (ABCC ... For importers, since translocation is directed from the periplasm to the cytoplasm, then the outward-facing conformation will ...
... unlike the majority of genes along the sex chromosomes. Since individuals of either sex will receive two copies of every gene ... Chromosomal translocations which place the XIC on an autosome lead to inactivation of the autosome, and X chromosomes lacking ... 2.Maternal X chromosome 3.Paternal X chromosome 4.Mitosis and random X chromosome inactivation event 5.Paternal chromosome is ... Selection of one active X chromosome[edit]. Normal females possess two X chromosomes, and in any given cell one chromosome will ...
In gene conversion, a section of genetic material is copied from one chromosome to another, without the donating chromosome ... Sex in microbial pathogens. Infect Genet Evol. 2018 Jan;57:8-25. doi: 10.1016/j.meegid.2017.10.024. Epub 2017 Oct 27. Review. ... This can cause chromosomal translocations, sometimes leading to cancer. In B cellsEdit. Main article: Immunoglobulin class ... This process appears to be an adaptation for repairing DNA damages in the recipient chromosome by HRR.[11] Transformation may ...
Autosome/Sex chromosome (or allosome or heterosome). *Macrochromosome/Microchromosome. *Circular chromosome/Linear chromosome ... T-cell leukemia translocation altered gene. *Usher syndrome. *von Hippel-Lindau syndrome ... Chromosome 3 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 3 ... "Chromosome 3". Genetics Home Reference. Retrieved 2017-05-06.. *. "Chromosome 3". Human Genome Project Information Archive 1990 ...
XX male syndrome/46,XX testicular disorders of sex development. *Marker chromosome ... Translocations. Leukemia/lymphoma. Lymphoid. *Burkitt's lymphoma t(8 MYC;14 IGH). *Follicular lymphoma t(14 IGH;18 BCL2) ... Ring chromosome 18 syndrome. Ring 18 is a genetic condition caused by a deletion of the two tips of chromosome 18 followed by ... A ring-shaped chromosome is the result. In the case of ring 18, one of the two copies of chromosome 18 has formed a ring. ...
So, when the chromosomes go on to meiosis II and separate, some of the daughter cells receive daughter chromosomes with ... "Sex as a response to oxidative stress: a twofold increase in cellular reactive oxygen species activates sex genes". Proc. R. ... "Non-allelic homologous recombination between retrotransposable elements is a driver of de novo unbalanced translocations" ... Crossover usually occurs when matching regions on matching chromosomes break and then reconnect to the other chromosome. ...
These genes are found on all chromosomes, except the 22 and Y chromosome. High clustering on 6p is observed (140 tRNA genes), ... tRFs have multiple dependencies and roles; such as exhibiting significant changes between sexes, among races and disease status ... synthesis of the new polypeptide and translocation (movement) of the ribosome along the mRNA. If the tRNA's anticodon matches ... as well on 1 chromosome.[25]. The HGNC, in collaboration with the Genomic tRNA Database (GtRNAdb) and experts in the field, has ...
... in this case the X and Y or two X sex chromosomes, fail to separate, producing a sperm with an X and a Y chromosome or an egg ... Translocations. Leukemia/lymphoma. Lymphoid. *Burkitt's lymphoma t(8 MYC;14 IGH). *Follicular lymphoma t(14 IGH;18 BCL2) ... The underlying mechanisms involves at least one extra X chromosome in addition to a Y chromosome such that the total chromosome ... Nondisjunction occurs when sister chromatids on the sex chromosome, in this case an X and an X, fail to separate. An XX egg is ...
The next frequently involved are 9, 13, 15, 18, 20 and 22.[8] It has been observed that CPM involving the sex chromosomes ... Translocations. Leukemia/lymphoma. Lymphoid. *Burkitt's lymphoma t(8 MYC;14 IGH). *Follicular lymphoma t(14 IGH;18 BCL2) ... We will explore chromosome specific cases in the chromosome specific section.. *Type of chromosome abnormality: The factor that ... Specific chromosomes: The influence of CPM on fetal growth is chromosome specific. Certain chromosomes carry imprinted genes ...
So, in normal diploid organisms, autosomal chromosomes are present in two copies. There may, or may not, be sex chromosomes. ... as in the presence of extra or missing chromosomes, or structural, as in derivative chromosome, translocations, inversions, ... The normal human karyotypes contain 22 pairs of autosomal chromosomes and one pair of sex chromosomes (allosomes). Normal ... The karyotype of humans includes only 46 chromosomes.[15][16] The great apes have 48 chromosomes. Human chromosome 2 is now ...
... including 22 homologous chromosome pairs and a pair of sex chromosomes. The mitochondrial genome is a circular DNA molecule ... "Ribosome binding of a single copy of the SecY complex: implications for protein translocation" (PDF). Molecular Cell. 28 (6): ... linear molecules (chromosomes) with histone proteins RNA/protein synthesis coupled in the cytoplasm RNA synthesis in the ... The DNA of a prokaryotic cell consists of a single circular chromosome that is in direct contact with the cytoplasm. The ...
The distinct chromosome territories of chromosome 2 (red) and chromosome 9 (green) are stained with fluorescent in situ ... Bell PJ (November 2006). "Sex and the eukaryotic cell cycle is consistent with a viral ancestry for the eukaryotic nucleus". ... Specialized export proteins exist for translocation of mature mRNA and tRNA to the cytoplasm after post-transcriptional ... The mitotic spindle can be seen, stained green, attached to the two sets of chromosomes, stained light blue. All chromosomes ...
... or a variant translocation involving another chromosome or chromosomes as well as the long arm of chromosomes 9 and 22. Other ... XX male syndrome/46,XX testicular disorders of sex development. *Marker chromosome ... The Philadelphia chromosome or Philadelphia translocation (Ph) is a specific genetic abnormality in chromosome 22 of leukemia ... It arises from the translocation, which is termed t(9;22)(q34.1;q11.2), between chromosome 9 and chromosome 22, with breaks ...
SEX CHROMOSOME TRANSLOCATIONS IN THE EVOLUTION OF REPRODUCTIVE ISOLATION Message Subject (Your Name) has forwarded a page to ... SEX CHROMOSOME TRANSLOCATIONS IN THE EVOLUTION OF REPRODUCTIVE ISOLATION. Martin L. Tracey ... SEX CHROMOSOME TRANSLOCATIONS IN THE EVOLUTION OF REPRODUCTIVE ISOLATION. Martin L. Tracey ... SEX CHROMOSOME TRANSLOCATIONS IN THE EVOLUTION OF REPRODUCTIVE ISOLATION. Martin L. Tracey ...
Translocations in Sciara; Their Bearing on Chromosome Behavior and Sex Determination HELEN V. CROUSE (Publication Authorized ... Translocations in Sciara; Their Bearing on Chromosome Behavior and Sex Determination HELEN V. CROUSE (Publication Authorized ... Translocations in sciara: their bearing on chromosomes behavior and sex determination. age000379p0001. Previous. 1 of 75. Next ...
Evolution of recombination rates between sex chromosomes. Deborah Charlesworth. Phil. Trans. R. Soc. B 2017 372 20160456; DOI: ...
The largest number of multiple sex chromosomes in vertebrates known today is found in the monotreme... ... Heteromorphic sex chromosomes are common in eukaryotes and largely ubiquitous in birds and mammals. ... Homomorphic XY sex chromosomes and derived Y-autosome translocation in Eleutherodactylus riveroi (Anura, Leptodactylidae). ... How did the platypus get its sex chromosome chain? A comparison of meiotic multiples and sex chromosomes in plants and animals ...
Chromosome rearrangements Definition A chromosome rearrangement is a structural change in a chromosome such as a deletion, ... except for the sex chromosomes X and Y. Sex chromosome trisomies and monosomy for the X chromosome are associated with less ... The "Philadelphia chromosome" is a translocation that fuses parts of chromosomes 9 and 22, which produces a new gene product ... The final pair of chromosomes, called the sex chromosomes, determine the sex of the individual. Women possess two identical ...
ZW Sex Chromosomes in Australian Dragon Lizards (Agamidae) Originated from a Combination of Duplication and Translocation in ... ZW Sex Chromosomes in Australian Dragon Lizards (Agamidae) Originated from a Combination of Duplication and Translocation in ...
Analysis of gametes and embryos from translocation carriers reveals sex-specific differences in chromosome segregation patterns ... Analysis of gametes and embryos from translocation carriers reveals sex-specific differences in chromosome segregation patterns ... Analysis of gametes and embryos from translocation carriers reveals sex-specific differences in chromosome segregation patterns ... Non-invasive test for chromosome abnormalities in womens eggs * Painful periods increase pain sensitivity throughout the month ...
The first pair of metacentric chromosomes has been proposed as a proto sex-chromosome originated by a Robertsonian fusion ... A total of 88 genes annotated within of 14 BACs located in the chromosome 1 of S. senegalensis were used to elaborate syntenic ... In order to elucidate a possible evolutionary origin of this chromosome 1, studies of genomic synteny were carried out with ... This region contains all the dmrt genes, which are associated with sex determination in some species. In addition, the presence ...
Prenatal diagnosis of sex chromosome aneuploidy. Ring chromosomes. Robertsonian translocations. Sex chromosome mosaicism. ... Supernumerary marker chromosomes (SMCs) postnatal. Supernumerary marker chromosomes (SMCs) prenatal. Triploidy (69,XXX, 69XXY ... Autosomal reciprocal translocations postnatal. Autosomal reciprocal translocations prenatal. Cell division mitosis, meiosis and ... X-autosome translocations. Pregnancy and fertility Anterior abdominal wall defects. Assisted reproductive technology: in vitro ...
Sex Chromosomes. Genetic problems also occur when abnormalities affect the sex chromosomes. Normally, a child will be a male if ... chromosome 7).. In translocations (which affect about 1 in every 400 newborns), bits of chromosomes shift from one chromosome ... In addition, females have two X chromosomes and males have one X and one Y chromosome. The X and the Y are known as sex ... Deletions, Translocations, and Inversions. Sometimes its not the number of chromosomes thats the problem, but that the ...
... in structurally abnormal X chromosomes is relevant to the study of the genetic activity of mammalian sex chromosomes. So far, ... In females heterozygous for Searles translocation (T16H), in which part of the X chromosome is translocated on to an ... Within the framework of this hypothesis, late DNA synthesis and genetic inactivity of the same X chromosome are considered ... In human females, structurally abnormal X chromosomes, such as deficiencies, duplication/deficiencies or rings, were found to ...
The basal lineage of monotremes features an extraordinarily complex sex chromosome system which has provided novel insights ... likely have differentiated on heteromorphic sex chromosomes before X autosome translocations led to this sex chromosome complex ... In some lineages, sex chromosomes have been conserved (for example, the XY sex chromosomes in therian mammals and the ZW in ... The multiple sex chromosome system in monotreme mammals defies most of the rules that seem to apply to other sex chromosome ...
2). In Z. rouxii, similarly to Tetrapisispora blattae, a translocation has joined the X side of MAT to a telomeric region ... Sex chromosomes are subject to unique evolutionary processes and mechanisms (5, 45-47). Our observations about the yeast MAT ... Evolutionary erosion of yeast sex chromosomes by mating-type switching accidents. Jonathan L. Gordon, David Armisén, Estelle ... Evolutionary erosion of yeast sex chromosomes by mating-type switching accidents. Jonathan L. Gordon, David Armisén, Estelle ...
... maintains sex chromosome association. In this report we present results on the process of meiotic sex chromosome pairing ... According to this genetic differentiation, sex chromosomes do not synapse during the first meiotic prophase in males, and a ... We have investigated the relationships between the axial structures organized along sex chromosomes and the formation of the ... This situation could have influenced the further evolution of sex chromosomes in marsupials. ...
... and gross chromosomal translocations. The gender of the fetus is identified from the sex chromosomes, and can be reported to ... Humans have 23 pairs of chromosomes including the sex chromosomes. Rearrangements of the chromosomes or the presence of ... Humans have 23 pairs of chromosomes including the sex chromosomes.. Down syndrome- A chromosomal disorder caused by an extra ... Chromosomes- Tightly compressed rod-like structures that carry DNA; humans have 23 pairs of chromosomes including the sex ...
Classification: Autosome , Sex chromosome. Evolution: Chromosomal inversion , Chromosomal translocation , Polyploidy. Category ... An autosome is a non-sex chromosome. It is an ordinary paired chromosome that is the same in both sexes of a species. For ... The X and Y chromosomes are not autosomal.. Non-autosomal chromosomes are usually referred to as sex chromosomes or, less ...
... and cigarette smoking on background translocation yields have not been examined systematically. Further, the shape ... Chromosome translocations in peripheral blood lymphocytes of normal, healthy humans increase with age, but the effects of ... Sex Factors. Smoking. Translocation, Genetic*. Grant Support. ID/Acronym/Agency: P01 CA059431-060001/CA/NCI NIH HHS; P01 ... Chromosome translocations in peripheral blood lymphocytes of normal, healthy humans increase with age, but the effects of ...
There are 46 chromosomes in each cell, apart from red blood cells and the sex cells. Those 46 chromosomes are 23 pairs, ... Sometimes, a translocation occurs and theres no additional genetic material in the cell. The portion of chromosome 13 that is ... The names given to these mutations are nondisjunction of chromosomes and Robertsonian translocation. ... Here a copy or partial copy of chromosome 13 randomly attaches itself to another chromosome. ...
Due to an X-autosome translocation, S. delicatus has an XY1Y2 sex chromosome system, rare in mammals. During meiotic prophase, ... Lanzone, C.; Rodríguez, D.; Cuello, P.; Albanese, S.; Ojeda, A.; Chillo, V.; Martí, D. A. (2011). "XY1Y2 chromosome system in ... a males X and two Y chromosomes form a trivalent. The female value of 18 is the lowest diploid number of any species in the ... it appears that major chromosome restructuring occurred during the evolution of the Andalgalomys-Salinomys clade. While not ...
"Widespread Translocation from Autosomes to Sex Chromosomes Preserves Genetic Variability in an Endangered Lark". Journal of ... The adult sex ratio is unbalanced, with a high proportion of the population being male. The Raso lark feeds by digging in the ... Both sexes also feed on grass seeds, and insects such as butterflies, moths and grasshoppers. Food and water for the Raso lark ... The tiny population size, which fluctuates from ~200-1,000 birds, coupled with the highly skewed sex ratio (around two males to ...
... derived variants like neo-XY in males evolved several times independently by Robertsonian translocation. This is the case of ... These results imply differential amplification of satDNAs on neo-Y chromosome and a minor role of TEs in sex chromosome ... Finally, the species is an example of the action of repetitive DNAs in the generation of variability for sex chromosomes after ... We showed highly differentiated neo-XY sex chromosomes owing to major amplification of satDNAs in neo-Y. Furthermore, ...
Suppressed Recombination of Sex Chromosomes Is Not Caused by Chromosomal Reciprocal Translocation in Spiny Frog (Quasipaa ...
This is the fourth edition of an acclaimed introductory textbook on the structure and function of human chromosomes. The ... Sex Determination and the Y Chromosome. Pages 255-266. Miller, Orlando J. (et al.) ... Clinical Importance of Translocations, Inversions, and Insertions. Pages 239-254. Miller, Orlando J. (et al.) ... This is the fourth edition of an acclaimed introductory textbook on the structure and function of human chromosomes. The ...
Studies indicate that the X chromosome can determine the levels of sex hormones. A study has shown an association between ... XXY males with SLE have an abnormal X-Y translocation resulting in the partial triplication of the PAR1 gene region.[104] ... The X chromosome carries immunological related genes, which can mutate and contribute to the onset of SLE. The Y chromosome has ... Sex. SLE, like many autoimmune diseases, affects females more frequently than males, at a rate of about 9 to 1.[5][95] ...
... homologous chromosomes, monosomes, Philadelphia chromosomes, sex chromosomes, somatic chromosomes, and W chromosomes. See also ... Ph1 chromosome (Philadelphia chromosome) an abnormality of chromosome 22, characterized by the translocation of genetic ... A-Chromosomes 1-3.. B-Chromosomes 4, 5.. C-Chromosomes 6-12; X chromosome.. D-Chromosomes 13-15.. E-Chromosomes 16-18.. F- ... Ring chromosome, Sex chromosome, Translation, Transcription. ,Unbanded chromosome, X chromosome, Y chromosome.. chro·mo·some. ( ...
Chromosome abnormalities have been known for over 50 years, though the methods of analysis have become increasing more ... 5. Autosomal reciprocal translocations. 6. Sex chromosome translocations. 7. Robertsonian translocations. 8. Centromere ... Autosomal ring chromosomes. 12. Complex rearrangements. 13. Parental sex chromosome aneuploidy. 14. Parental autosomal ... Chromosomal disorders of sex development. 21. Chromosome instability syndromes. DISORDERS ASSOCIATED WITH ABERRANT GENOMIC ...
Sex chromosome mosaics were the most frequent, 43% (31/72); followed by autosomal, 36.1% (26/72); those of marker chromosomes, ... apparently balanced structural alterations, such as translocations, inversions and insertions. unbalanced structural ... marker chromosomes, rare aneuploidies (of chromosomes 22 and 9), triploidies, X-chromosome polysomies and 46,XY/46,XX, as ... the most frequent sex chromosome aneuploidies, such as Turner syndrome (45,X); 47,XXX; Klinefelter syndrome (47,XXY) and 47,XYY ...
... chromosome pairs 1 to 22 and one pair of sex chromosomes (XX for females and XY for males). See Translocation. ... The order, number and appearance of chromosomes within a cell. There are 46 human chromosomes with the sex chromosomes shown as ... Because chromosome 22 is a very short chromosome and chromosome 9 is a very long one, the lengthening of chromosome 9 was less ... Translocation. An abnormality of chromosomes in the marrow or lymph node cells that occurs when a piece of one chromosome ...
What are karyotypes and what information do they tell about an organisms chromosomes? The questions in this interactive quiz ... Distinguish differences between homologous chromosomes and sex chromosomes *Recall the different disorders that can occur from ... 2. How many total chromosomes are there in the karyotype of a normal human?. ... The number and appearance of chromosomes in an organism is called a ______.. ...
Humans have 23 pairs of chromosomes or a total of 46 chromosomes. One pair of these chromosomes determines the sex of a person ... These include abnormalities due to deletions, duplications, translocations, inversions, or rings. Deletions are when a part of ... which is an absence of that entire sex chromosome, leaving only 45 chromosomes. Women affected by Turner Syndrome usually have ... An individual who suffers from Down Syndrome, also known as Trisomy 21 would have three copies of chromosome 21 instead of the ...
  • The most common chromosomal disorder is Down syndrome , a combination of mental and physical abnormalities caused by the presence of an extra copy of chromosome 21. (encyclopedia.com)
  • Chromosome abnormalities have been known for over 50 years, though the methods of analysis have become increasing more sophisticated and precise. (oup.com)
  • This new edition of Chromosome Abnormalities and Genetic Counseling deals with these universal questions, and in the context of the recent developments in molecular cytogenetic analysis, but retaining always the major focus on the needs of the families in which these conditions occur. (oup.com)
  • Cytogenetic disorders with visible chromosomal abnormalities are evidenced by either an abnormal number of chromosomes or some alteration in the structure of one or more chromosomes. (thefreedictionary.com)
  • Either trisomy or monosomy involving the sex chromosomes yields relatively mild abnormalities. (thefreedictionary.com)
  • The total incidence of sex chromosome abnormalities was 1 per 426 children or 2.34 per 1000. (nih.gov)
  • The most frequent autosomal abnormalities were that of Down's syndrome with 1 per 592 children, and reciprocal translocations with 1 per 712 children. (nih.gov)
  • Chromosome abnormalities were found in 276 liveborn children and in 19 fetuses, who were aborted after prenatal chromosome examination. (nih.gov)
  • The combined incidence of sex chromosomal and autosomal abnormalities was 1 per 118 children or 8.45 per 1000 children. (nih.gov)
  • Chromosomal abnormalities occur as a result of errors in cell division, resulting in an incorrect number of chromosomes within that cell. (scrcivf.com)
  • FISH is a sensitive and useful adjunct to cytogenetic testing for the detection of abnormalities of chromosomal structure or numbers (eg, deletions, translocations, duplications, aneuploidy). (edu.au)
  • The American Congress of Obstetricians and Gynecologists (ACOG) recommends that diagnostic testing for chromosome abnormalities and open neural tube defects (ONTD) be offered to all pregnant women. (arupconsult.com)
  • What are chromosome abnormalities? (chkd.org)
  • Chromosome abnormalities in the baby may be inherited from the parent or may occur with no family history. (chkd.org)
  • or by abnormalities of chromosome 11q23 have particularly poor prognoses with chemotherapy. (rexhealth.com)
  • Pre-Implantation Genetic Screening (PGS), is a procedure designed to examine your embryos for chromosome abnormalities. (nccrm.com)
  • Chromosome abnormalities may result in aneuploidy (wrong number-e.g. (nccrm.com)
  • The screening aims at improving pregnancy rate by testing your embryos for chromosome abnormalities-an increasing problem for families who choose to have children later in life. (nccrm.com)
  • The first pair of metacentric chromosomes has been proposed as a proto sex-chromosome originated by a Robertsonian fusion between acrocentric chromosomes. (mdpi.com)
  • The other type of mutation that causes Patau syndrome is a Robertsonian translocation. (brighthub.com)
  • However, in some species, derived variants like neo-XY in males evolved several times independently by Robertsonian translocation. (nature.com)
  • The objective of the present study is to provide more genetic information about meiotic segregation behavior and the possibility of interchromosomal effects (ICE) in spermatozoa from carriers of Robertsonian (Rob) translocation. (alliedacademies.org)
  • The remaining 3 percent have a Robertsonian translocation in which all or part of an extra chromosome 21 is fused with another chromosome. (aafp.org)
  • Signs of a Robertsonian translocation In most court cases, there aren't any indicators or visible indications of a Robertsonian translocation. (nonamepub.com)
  • One of the structural chromosomopathies is the Robertsonian translocation, defined as the fusion of two non-homologous acrocentric chromosomes (1,2,3). (thefreedictionary.com)
  • Robertsonian translocations (ROBs) are whole arm rearrangements involving the acrocentric 13-15 and 21-22 chromosomes and carriers are at increased risk for aneuploidy and thus uniparental disomy (UPD). (thefreedictionary.com)
  • The number of sex chromosomes is larger than the number of autosomes found, and these data represent the largest number of multiple sex chromosomes ever found among vertebrate species. (springer.com)
  • Every human cell contains 46 chromosomes, arranged as 23 pairs (called autosomes), with one member of each pair inherited from each parent at the time of conception. (kidshealth.org)
  • Recently, sequence information from autosomes, X chromosomes, and XY-shared pseudoautosomal regions has become available. (springer.com)
  • Such a pattern of gene evolution has been shown for genes that have retroposed from autosomes to Y chromosomes (e.g. (springer.com)
  • Both males and females have 22 pairs of chromosomes, called the autosomes, that are numbered one to twenty-two in order of decreasing size. (encyclopedia.com)
  • Each organism of a species is normally characterized by the same number of chromosomes in its somatic cells, 46 being the number normally present in humans, including 22 pairs of autosomes and the two sex chromosomes (XX or XY), which determine the sex of the organism. (thefreedictionary.com)
  • The latter arm of the neo-sex chromosome is synchronous with other autosomes of the complement. (ias.ac.in)
  • Zakian, S. 2004-10-19 00:00:00 The X and Y chromosomes of mammals, which significantly differ in structure and genetic composition, are thought to originate from a pair of autosomes. (deepdyve.com)
  • In Drosophila , however, sex is determined by the ratio of X chromosomes to autosomes. (scienceblogs.com)
  • Long story short, a new Y chromosome may evolve when one of the autosomes fuses to the X chromosome. (scienceblogs.com)
  • As I mentioned above, sex is determined by the ratio of X chromosomes to autosomes. (scienceblogs.com)
  • In Drosophila, genes expressed in males tend to accumulate on autosomes and are underrepresented on the X chromosome. (nih.gov)
  • In particular, genes expressed in testis have been observed to frequently relocate from the X chromosome to the autosomes. (nih.gov)
  • The inactivation of X-linked genes during male meiosis (i.e., meiotic sex chromosome inactivation-MSCI) was first proposed to explain male sterility caused by X-autosomal translocation in Drosophila, and more recently it was suggested that MSCI might provide the conditions under which selection would favor the accumulation of testis-expressed genes on autosomes. (nih.gov)
  • Humans have 46 chromosomes that include 22 pairs of autosomes and an additional two sex chromosomes (XX in a woman and XY in a man). (southwestvasectomyreversal.com)
  • Half of them (22 autosomes + X or Y chromosome) are inherited from the father and the other half (22 autosomes + X chromosome), from the mother. (biology-online.org)
  • Humans normally have 23 pairs of chromosomes, including 22 pairs of non-sex-determining chromosomes (also known as autosomes) and 1 pair of sex chromosomes (XX for females, XY for males). (labcorp.com)
  • In this model, the emergence of a locus with female fertility and male sterility and another locus with male fertility and female sterility led to the establishment of a small sex-determining region on ordinary autosomes in hermaphrodite ancestors. (biomedcentral.com)
  • If the gene is on one of the first 22 pairs of chromosomes, called the autosomes, the genetic disorder is called an autosomal condition. (cdc.gov)
  • A total of 88 genes annotated within of 14 BACs located in the chromosome 1 of S. senegalensis were used to elaborate syntenic maps. (mdpi.com)
  • This region contains all the dmrt genes, which are associated with sex determination in some species. (mdpi.com)
  • Along the segments of our DNA, genes are neatly packaged within structures called chromosomes . (kidshealth.org)
  • The generally accepted model of sex chromosome evolution is that accumulation of sexually antagonist genes in proximity of a sex-determining locus provides a selective advantage for lack of recombination between sex chromosomes (Charlesworth 1991 ). (springer.com)
  • 2011 ). Differentiation of genes as a result of sex chromosome evolution presents an opportunity for subfunctionalization and neofunctionalization of the gene on the sex-specific chromosome (Y or W chromosome). (springer.com)
  • This can occur via mutation in the non-recombining part and the frequent duplication events that often result in multiple copies of genes on Y chromosomes (Wilson and Makova 2009 ). (springer.com)
  • Each type of chromosome contains different genes that are found at specific locations along the chromosome. (encyclopedia.com)
  • Sometimes amplified genes form a separate and unique chromosome and sometimes they are located within an otherwise normal chromosome. (encyclopedia.com)
  • A chromosome rearrangement can delete or disrupt the functioning of genes that are located on the chromosomal pieces involved. (encyclopedia.com)
  • Chromosome rearrangements that delete or disrupt genes that regulate the cell cycle can contribute to the transformation of a normal cell into a cancerous cell. (encyclopedia.com)
  • Evolutionary history of novel genes on the tammar wallaby Y chromosome: Implications for sex chromosome evolution. (semanticscholar.org)
  • Chromosomes contain these genes and DNA. (bartleby.com)
  • Along with this delay in replication timing, estimated to be 2-3 hr, the majority of genes become transcriptionally silenced on one X chromosome. (jove.com)
  • The short arms also join to form a reciprocal product, which in the acrocentric chromosomes, typically contains nonessential genes and repetitive sequences such as nucleolar organizing regions, and is usually lost within a few cell divisions. (alliedacademies.org)
  • Some genes on the X chromosome escape X-inactivation. (medlineplus.gov)
  • Many of these genes are located at the ends of each arm of the X chromosome in areas known as the pseudoautosomal regions. (medlineplus.gov)
  • Although many genes are unique to the X chromosome, genes in the pseudoautosomal regions are present on both sex chromosomes. (medlineplus.gov)
  • Identifying genes on each chromosome is an active area of genetic research. (medlineplus.gov)
  • Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. (medlineplus.gov)
  • The X chromosome likely contains 800 to 900 genes that provide instructions for making proteins. (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)
  • Because only males have the Y chromosome, the genes on this chromosome tend to be involved in male sex determination and development. (medlineplus.gov)
  • Other genes on the Y chromosome are important for enabling men to father biological children (male fertility). (medlineplus.gov)
  • An extra copy of the genes contained in the pseudoautosomal region of the Y chromosome may explain the tall stature and other features that can affect boys and men with this condition. (medlineplus.gov)
  • In this review, in context of a comparison permitting to trace this evolutionary pathway, we consider the structural features of mammalian sex chromosomes focusing on the X-chromosomal genes and the unique epigenetic mechanism of their regulation. (deepdyve.com)
  • Possible causes and consequences of the genes escaping X inactivation and aspects of molecular mechanism of X-chromosome inactivation are discussed. (deepdyve.com)
  • They found that during evolution, a reshuffling of DNA known as translocation brought together separate chunks of sex-determining genes onto a single chromosome, essentially mimicking the human X or Y chromosome. (duke.edu)
  • In the 1960's, Japanese-American geneticist and evolutionary biologist Susumu Ohno proposed a theory in which the genes determining sex first arose at various spots scattered across the entire genome, but over time were "captured" on the sex chromosomes. (duke.edu)
  • In C. amylolentus, dozens of genes at two different locations on the chromosomes control what's called a tetrapolar, or four-part, mating system. (duke.edu)
  • The researchers sequenced the entire genome of C. amylolentus, mapping the location of all the genes as well as the centromeres on each of the organism's 14 chromosomes. (duke.edu)
  • Furthermore, we have identified novel partner genes and shown that IGH translocations can represent both primary and secondary events. (ncl.ac.uk)
  • In mammals, sex is determined by genes on the Y chromosome. (scienceblogs.com)
  • That's because the Y chromosome is not a degraded X chromosome, and it does not possess the genes for male sex determination (see here for some work on Y chromosome evolution in Drosophila ). (scienceblogs.com)
  • That means that XO flies are males -- although they are often sterile because the Y chromosome carries genes necessary for gametogenesis in many species. (scienceblogs.com)
  • The increased gene dosage of three X/Y chromosome pseudoautosomal region (PAR1) SHOX genes has been postulated as a cause of the increased stature seen in all three sex chromosome trisomies: 47,XXX, 47,XXY, and 47,XYY. (wikipedia.org)
  • If the translocation is balanced - genes simply swap places - then the individual may suffer few effects. (abpischools.org.uk)
  • Third, we found that autosomal genes relocated through retroposition from the X chromosome were more often highly expressed in meiosis in contrast to their X-linked parents. (nih.gov)
  • A number of the affected genes can be found along the duration of the derived chromosome 11. (nonamepub.com)
  • Homologous chromosomes have alleles on the same genes located in the same loci. (biology-online.org)
  • Heterologous chromosomes have alleles on different genes. (biology-online.org)
  • a researcher at the University of Minnesota College of Biological Sciences discovered that the linear arrangement of genes on a chromosome corresponds to the development of body segments in fruit flies ? (thefullwiki.org)
  • Chromosomes are the parts of a body cell that carry genes. (hse.ie)
  • The disorder is determined by genes on the X chromosome. (chkd.org)
  • Translocations and deletions can give valuable clues to the locations and functions of particular genes. (asmscience.org)
  • A chromosome contains numerous genes and is made of two sister chromatids joined by a centromere. (infoplease.com)
  • The genes that reside on chromosomes form the blueprints for the production of thousands of proteins. (labcorp.com)
  • Sometimes changes can occur to a person's chromosomes and/or genes during their lifetime because of exposures to radiation, toxins, or for unknown reasons. (labcorp.com)
  • In about 2% of APL cases, other translocations involving the RARA gene and genes other than PML have been reported. (labcorp.com)
  • We discovered with our first scientific paper on this in 1995 that the Y chromosome contains many genes that are involved in spermatogenesis, and deletions involving these genes are often found in infertile males. (infertile.com)
  • Furthermore, we find that the translocation directly disrupts two genes. (asm.org)
  • We have determined that this particular isolate contains a chromosomal translocation that directly interrupts two genes, which all descendants of this strain from various research laboratories appear to possess. (asm.org)
  • People get (inherit) their chromosomes , which contain their genes , from their parents. (cdc.gov)
  • One of these features is the absence of a homologous region between X and Y chromosomes. (semanticscholar.org)
  • In the language of the geneticist, trisomy refers to the presence of an additional chromosome that is homologous with one of the existing pairs so that that particular chromosome is present in triplicate. (thefreedictionary.com)
  • The term monosomy refers to the absence of one of a pair of homologous chromosomes. (thefreedictionary.com)
  • Homologous chromosomes usually replicate synchronously, however there are notable exceptions to this rule. (jove.com)
  • This method allows for a direct comparison of replication timing between homologous chromosomes within the same cell, and was adapted from 6 . (jove.com)
  • This method has advantages over recently developed high throughput micro-array or sequencing protocols that cannot distinguish between homologous alleles present on rearranged and un-rearranged chromosomes. (jove.com)
  • The mammalian, snake, and bird sex chromosomes all descended from different autosomal ancestors -- the sex chromosomes in one taxon are not homologous to those from the other taxa. (scienceblogs.com)
  • In mammalian meiotic prophase, homologous chromosome recognition is aided by formation and repair of programmed DNA double-strand breaks (DSBs). (biomedcentral.com)
  • Subsequently, stable associations form through homologous chromosome synapsis. (biomedcentral.com)
  • In male mouse meiosis, the largely heterologous X and Y chromosomes synapse only in their short pseudoautosomal regions (PARs), and DSBs persist along the unsynapsed non-homologous arms of these sex chromosomes. (biomedcentral.com)
  • In the first meiotic division, homologous chromosomes need to segregate faithfully, to generate two daughter cells that both carry a haploid set of chromosomes. (biomedcentral.com)
  • A '''homologous chromosome''' pertains to one of a pair of [[chromosome]]s with the same gene sequence, loci, chromosomal length, and centromere location. (biology-online.org)
  • A homologous pair consists of one paternal and one maternal chromosome. (biology-online.org)
  • Typically, a female will have 23 homologous chromosomes whereas a male will have 22. (biology-online.org)
  • That is because the sex chromosomes, X and Y, in males are not homologous. (biology-online.org)
  • The pairing up of homologous chromosomes during meiosis is important to promote genetic variation. (biology-online.org)
  • Because of the genetic recombination that occurs between homologous pairs at meiosis, the resulting haploid gametes contain chromosomes that are genetically different from each other. (biology-online.org)
  • Homologous chromosome definition == In biology, homologous chromosomes are ''paired'' chromosomes. (biology-online.org)
  • The homologous pair is comprised of a paternal chromosome and a maternal chromosome. (biology-online.org)
  • Homologous chromosomes vs. heterologous chromosomes == When chromosomes are ''homologous'', it means that they are the ''same'', at least in terms of the gene sequences and loci. (biology-online.org)
  • This means that heterologous (non-homologous) chromosomes would, therefore, pertain to any two chromosomes that are ''different'', such as in terms of gene sequence and loci. (biology-online.org)
  • During meiosis, homologous chromosomes may naturally exchange genetic material. (biology-online.org)
  • For the comparison between homologous chromosomes and heterologous chromosomes, see table below. (biology-online.org)
  • Homologous chromosomes showing sister and non-sister chromatids. (biology-online.org)
  • At meiosis, each of the homologous chromosomes is comprised of two identical chromatids joined together by a common [[kinetochore]] (centromere). (biology-online.org)
  • Uniparental disomy is the inheritance of two homologous chromosomes from one parent. (thefullwiki.org)
  • Our results strongly support the hypothesis that all cryptobranchid species possess homologous systems of female heterogamety, despite maintenance of homomorphic sex chromosomes over nearly 60 million years. (g3journal.org)
  • Homologous chromosomes are inherited from each parent and are the two chromosomes that make up a pair in a diploid cell. (infoplease.com)
  • The functional difference between mitosis and meiosis occurs in meiosis I. A synapsis occurs during prophase I, where homologous chromosomes align next to each other. (infoplease.com)
  • Homologous chromosomes are the matched pair found in a diploid cell. (infoplease.com)
  • Recombination repression occurs in this region even if homologous sequences are present on both the Z and W chromosomes. (biomedcentral.com)
  • In meiosis, non-exchange homologous chromosomes are at risk for mis-segregation and should be monitored by the spindle assembly checkpoint (SAC) to avoid formation of aneuploid gametes. (biologists.org)
  • In preparation for the first meiotic division, homologous chromosomes (homologs) pair and recombine, align at the metaphase plate and then segregate into two daughter cells. (biologists.org)
  • Complex chromosomal rearrangements are structural genomic alterations involving multiple instances of deletions, duplications, inversions, or translocations that co-occur either on the same chromosome or represent different overlapping events on homologous chromosomes. (usda.gov)
  • When a piece of one chromosome is exchanged with a piece from another chromosome it is called a translocation. (encyclopedia.com)
  • The portion of chromosome 13 that is translocated has merely swapped placed with a portion of another chromosome. (brighthub.com)
  • When this happens, a piece from one chromosome breaks off and rejoins, not to one of the matching chromatids but to another chromosome entirely. (abpischools.org.uk)
  • When part of one chromosome is moved onto another chromosome where it does not normally belong. (southwestvasectomyreversal.com)
  • It can happen either within the same chromosome or move to another chromosome. (chkd.org)
  • Chromosomal disorders include gain or loss of an entire chromosome (aneuploidy), loss of part of one or more chromosomes (deletion), transfer of one segment of a chromosome to another chromosome (translocation), and reversal of a segment of a chromosome (inversion). (asmscience.org)
  • A translocation is when part of one chromosome has moved to another chromosome. (cdc.gov)
  • Blackmon H, Demuth JP (2015) The fragile Y hypothesis: Y chromosome aneuploidy as a selective pressure in sex chromosome and meiotic mechanism evolution. (nature.com)
  • The higher frequencies of aneuploidy for sex chromosome were observed. (alliedacademies.org)
  • Sex chromosome aneuploidy: the Denver Prospective Study. (medscape.com)
  • Incorrect homolog segregation results in abnormal chromosome number, i.e. aneuploidy, in the daughter cells. (biologists.org)
  • We showed highly differentiated neo-XY sex chromosomes owing to major amplification of satDNAs in neo-Y. Furthermore, chromosomal mapping of satDNAs suggests high turnover of neo-sex chromosomes in R. bergii at the intrapopulation level, caused by multiple paracentric inversions, amplifications, and transpositions. (nature.com)
  • The Chromosome Disorder Outreach, Inc., is an international, non-profit organization founded in 1992 to provide support & information to individuals affected by all rare chromosome disorders: deletions, duplications (trisomies), inversions, translocations, rings and the sex chromosome disorders (47XYY, 48 XXXX, 49 XXXXY etc). (rarediseases.org)
  • Sex Chromosomes Inversions have played an important role in the growth of sex chromosomes. (nonamepub.com)
  • For instance, when comparing human and chimp, there are many inversions where the DNA comes from exactly the same chromosome, but a certain region of the chromosome is inverted. (nonamepub.com)
  • We have investigated structural changes in genomic architecture such as inversions and translocations that distinguish the most pathogenic variety, Cryptococcus neoformans var. (asm.org)
  • PGS is typically prescribed for couples of advanced maternal age, known familial translocations/inversions, gene duplications, and deletions, or families who have had recurrent pregnancy losses both naturally and through IVF. (nccrm.com)
  • The X and Y chromosomes are not autosomal. (rightdiagnosis.com)
  • Non-autosomal chromosomes are usually referred to as sex chromosomes or, less frequently, as gonosomes. (rightdiagnosis.com)
  • Recent work from our lab indicates that disruption of discrete cis-acting autosomal loci result in an extremely late replicating phenotype that affects the entire chromosome 4 . (jove.com)
  • We can also trace the origins of the sex chromosomes back to an autosomal (non-sex chromosome) state. (scienceblogs.com)
  • One popular model of sex-chromosome evolution postulates that the sex-determining locus first arises when an autosomal gene involved in environmental sex determination acquires a new mutation that consistently gives rise to either male (in the case of the XX:XY system) or female (in the case of the ZZ:ZW system) development. (scienceblogs.com)
  • In Boston, USA 55% of 47,XYY boys (6 of 11) identified in a newborn screening program had learning difficulties and received part-time resource room help compared to 11% (1 of 9) in an above-average-IQ control group of 46,XY boys with familial balanced autosomal chromosome translocations. (wikipedia.org)
  • Mammalian sex chromosomes evolved from an ancient autosomal pair. (sun.ac.za)
  • In Alouatta caraya (68 specimens), a modal number of 2N=52, X1X1X2X2/X1X2Y1Y2, was established with its particular multiple chromosome sex system, involving a Y-autosomal translocation observed in meiosis. (asp.org)
  • Interestingly, fish, amphibians, and reptiles have sex determination mechanisms that do or do not involve morphologically differentiated sex chromosomes. (springer.com)
  • Determination of the sex of a fetus when the mother is known to be a carrier of a sex-linked genetic disease (for example, hemophilia A). (encyclopedia.com)
  • 2014) Sex determination: why so many ways of doing it? (nature.com)
  • Transitions between sex determination systems have occurred in many lineages of squamates and it follows that novel sex chromosomes will also have arisen multiple times. (jove.com)
  • Chromosomal conditions involving the sex chromosomes often affect sex determination (whether a person has the sexual characteristics of a male or a female), sexual development, and fertility. (medlineplus.gov)
  • E ditor -The SRY gene (sex determining region of Y) and AZF (azoospermia factor), a gene from a gene family with multiple members, are both localised on the Y chromosome and are crucial for testis determination and spermatogenesis, respectively. (bmj.com)
  • PGD is also the most reliable method of gender determination to enable choosing the sex of the infant, or to prevent a sex chromosome-linked disease. (scrcivf.com)
  • It is thought that the ancestral state of sex determination in vertebrates was through environmental cues. (scienceblogs.com)
  • The chromosomal sex determination systems are thought to be independently derived mechanisms (although see here for an alternative hypothesis). (scienceblogs.com)
  • More on sex determination in Drosophila can be found in Scott Gilbert's excellent developmental biology textbook. (scienceblogs.com)
  • Anyway, my reason for pointing out the dramatic difference between the mammalian XY system and that of Drosophila is to show how even sex determination systems that appear to be similar upon first glance are quite different upon closer inspection. (scienceblogs.com)
  • A few months ago I wrote the following: I should point out that the mammalian Y chromosome is an anomaly in origin and sex determination. (scienceblogs.com)
  • In fact, every single sex determination system and sex chromosome system that I know of differs from all of the others in some manner. (scienceblogs.com)
  • Therian mammals have an extremely conserved XX/XY sex determination system. (sun.ac.za)
  • Analysis of such individuals has revealed some of the molecules involved in sex determination, including one called SRY, which is important for testis formation. (novapublishers.com)
  • Systems of genetic sex determination and the homology of sex chromosomes in different taxa vary greatly across vertebrates. (g3journal.org)
  • Much progress remains to be made in understanding systems of genetic sex determination in non-model organisms, especially those with homomorphic sex chromosomes and/or large genomes. (g3journal.org)
  • We used reduced representation genome sequencing to investigate genetic sex determination systems in the salamander family Cryptobranchidae (genera Cryptobranchus and Andrias ), which typifies both of these inherent difficulties. (g3journal.org)
  • These findings inform hypotheses about the ancestral mode of sex determination in salamanders, but suggest that comparative data from other salamander families are needed. (g3journal.org)
  • Our results further demonstrate that massive genomes are not necessarily a barrier to effective genome-wide sequencing and that the resulting data can be highly informative about sex determination systems in taxa with homomorphic sex chromosomes. (g3journal.org)
  • Sex can be determined by several mechanisms, such as environmental stimuli (environmental sex determination) or genetic differences between males and females (genetic sex determination). (biomedcentral.com)
  • Genetic sex determination is mainly based on the acquisition of sex chromosomes, a more stable strategy than environmental determinism, especially when the environment becomes variable. (biomedcentral.com)
  • Meiotic analyses of Cebus apella and Saimiri boliviensis confirmed human-like XY chromosomal sex determination. (asp.org)
  • The program of sex chromosome pairing in meiosis is highly conserved across marsupial species: implications for sex chromosome evolution. (semanticscholar.org)
  • In nondisjunction the chromosome 13 pair fails to come apart during the cell division (meiosis) that leads to the formation of either an egg cell or a sperm cell. (brighthub.com)
  • Bidau CJ, Marti DA (2001) Meiosis and the neo-XY system of Dichroplus vittatus (Melanoplinae, Acrididae): a comparison between sexes. (nature.com)
  • In Rob translocations, at the end of meiosis I, segregation of the translocated and nontranslocated chromosomes from the two different chromosome pairs implicated leads to the formation of either balanced (alternate segregation mode) or unbalanced (adjacent 1, adjacent 2, and 3:1 segregation modes) gametes [ 2 , 3 ], which can segregate in different ways at anaphase. (alliedacademies.org)
  • The 46,XX male is caused by translocation of Y material (including the sex-determining region [SRY]) to the X chromosome during paternal meiosis. (medscape.com)
  • An incident in chromosome separation during anaphase II (of meiosis II) called nondisjunction can result in sperm cells with an extra copy of the Y-chromosome. (wikipedia.org)
  • The presence of a heterologous chromosome pair in males poses a challenge to male meiosis, and has specific consequences for the transcriptional activity of the sex chromosomes during spermatogenesis as explained below. (biomedcentral.com)
  • The process where haploid sex cells are created from diploid parents is called meiosis , and it occurs only in the reproductive organs. (infoplease.com)
  • Meiosis begins with the same G 1 , S, and G 2 stages as mitosis and also ends with a duplicate set of chromosomes. (infoplease.com)
  • I. Chromosome orientation on the monopolar spindle of meiosis I. (semanticscholar.org)
  • Finally, at late larval stages, the whole paternal chromosome complement is discarded during male meiosis I. As a consequence, only maternal chromosomes are retained in the sperm nucleus, and these chromosomes will be then recognized as paternal after fertilization. (biologists.org)
  • Importantly, studies on S. coprophila translocations and chromosome identification in S. reynoldsi led to the conclusion that it is the paternally derived non-disjoined X m chromosome from male meiosis II that is later eliminated from the soma and germline of the embryo ( Crouse, 1943 ). (biologists.org)
  • MAD2, are crucial for normal checkpoint function in many experimental systems, but surprisingly, apparently not in male meiosis, as indicated by the lack of chromosome segregation defects reported earlier in Mad2 +/− spermatocytes. (biologists.org)
  • In order to generate haploid gametes (ova and sperm in mammals), replicated chromosomes undergo two rounds of cell division: meiosis I and meiosis II. (biologists.org)
  • At least one crossover (reciprocal exchange between homologs) is formed per chromosome in meiosis I. Crossovers then mature into chiasmata. (biologists.org)
  • Males exhibited an astonishing stable ring-shaped meiotic chain composed of six X and six Y chromosomes. (springer.com)
  • In addition, females have two X chromosomes and males have one X and one Y chromosome. (kidshealth.org)
  • According to this genetic differentiation, sex chromosomes do not synapse during the first meiotic prophase in males, and a special structure, the dense plate, maintains sex chromosome association. (semanticscholar.org)
  • In grasshoppers, the X0 sex-determining system in males is considered ancestral. (nature.com)
  • While SLE can occur in both males and females, it is found far more often in women, and the symptoms associated with each sex are different. (wikipedia.org)
  • The polytene chromosome complement of males with a neo-X- and neo-Y-chromosomes has revealed asynchrony in replication between the two arms of the neo-sex chromosomes. (ias.ac.in)
  • X-inactivation ensures that females, like males, have one functional copy of the X chromosome in each body cell. (medlineplus.gov)
  • Extra genetic material from the X chromosome interferes with male sexual development, preventing the testes from functioning normally and reducing the levels of testosterone (a hormone that directs male sexual development) in adolescent and adult males. (medlineplus.gov)
  • Males with 47,XYY syndrome have one X chromosome and two Y chromosomes in each cell, for a total of 47 chromosomes. (medlineplus.gov)
  • Some males with 47,XYY syndrome have an extra Y chromosome in only some of their cells. (medlineplus.gov)
  • 48,XXYY syndrome, a condition that leads to infertility, developmental and behavioral disorders, and other health problems in males, is caused by the presence of an extra X chromosome and an extra Y chromosome in a male's cells. (medlineplus.gov)
  • 1-5 Sex reversal (XX males) may arise by translocation of sequences from Yp onto Xp owing to meiotic recombination. (bmj.com)
  • However, for the highly successful programme against the New World Screwworm Cochliomyia hominivorax both males and females had to be released [ 4 ], as there was - and still is - no sex separation system. (biomedcentral.com)
  • Breakpoints in iso-Yq, iso-Yp and X-Y translocation chromosomes and X-Y interchanges in XX males are also amenable to analysis. (bmj.com)
  • In Sciara , during the early syncytial divisions that follow the zygote constitution (A m A p X m X p X p ), a first elimination event occurs when one or two paternally derived X chromosomes (X p ) are discarded from all somatic cells depending on the future sex of the embryo (XX females or XO males, respectively). (biologists.org)
  • In 5 out of 6 previously unpublished XX males, SRY was translocated onto the terminal part of an X chromosome. (ugent.be)
  • This is the first report in which translocation of an SRY-bearing fragment to an X chromosome in XX males could be directly demonstrated. (ugent.be)
  • We collected existing data from 16 laboratories in North America, Europe, and Asia on TFs measured in peripheral blood lymphocytes by fluorescence in situ hybridization whole chromosome painting among 1933 individuals. (biomedsearch.com)
  • The effect of stimuli at a whole genome level is studied by using two-dimensional fluorescence in situ hybridization (FISH) to delineate whole chromosome territories within a cell nucleus, followed by a quantitative analysis of the spatial distribution of the chromosome. (jove.com)
  • In particular, an (AAT)n microsatellite repeat motif mapped by fluorescence in situ hybridization on part of W chromosome in V. acanthurus only, whereas a (CGG)n motif mapped onto the W chromosomes of V. gouldii and V. rosenbergi. (jove.com)
  • Analysis of sperm chromosomes was done by fluorescence in situ hybridization (FISH). (alliedacademies.org)
  • Using two independent approaches, fluorescence in situ hybridization (FISH) and interspecific backcross analysis, we show that Spam1 maps to proximal mouse Chromosome (Chr) 6. (deepdyve.com)
  • In this study, we could detect Y-specific sequences, including the sex-determining region of the Y chromosome (SRY), using fluorescence in situ hybridization. (ugent.be)
  • Patau syndrome is a severe chromosomal abnormality that is primarily caused by the addition of an extra copy of chromosome 13. (brighthub.com)
  • The syndrome is diagnosed in an increasing number of children prenatally by amniocentesis and chorionic villus sampling in order to obtain a chromosome karyotype, where the abnormality can be observed. (wikipedia.org)
  • Prenatal: Interphase FISH is a rapid diagnostic test when one of the commonly occurring trisomies (21, 18, 13) or a sex chromosome abnormality is suspected. (edu.au)
  • One parent has a chromosome abnormality. (chkd.org)
  • My patient has a family history of a chromosome abnormality. (questdiagnostics.com)
  • Do these results guarantee that my patient does not have the familial chromosome abnormality? (questdiagnostics.com)
  • My patient has a family history of a chromosome abnormality, but his/her chromosome analysis was reported as normal. (questdiagnostics.com)
  • Does this result guarantee that he/she doesn't have the familial chromosome abnormality? (questdiagnostics.com)
  • Documentation of the specific genetic test result in the family is necessary to determine if the type of testing that was performed on your patient is sufficient to identify the familial chromosome abnormality. (questdiagnostics.com)
  • Despite utilizing different sex chromosomes, the differentiation of male- or female-specific Y and W chromosomes due to lack of recombination is a common theme in sex chromosomes evolution, and leads to similar patterns of sequence differentiation on X/Y or Z/W chromosomes (Charlesworth et al. (springer.com)
  • While the X and Z chromosomes will undergo recombination in the homogametic sex, the Y and W chromosomes will accumulate mutations. (springer.com)
  • Finally, the species is an example of the action of repetitive DNAs in the generation of variability for sex chromosomes after the suppression of recombination, and helps understand sex chromosome evolution at the intrapopulation level. (nature.com)
  • Suppressed Recombination of Sex Chromosomes Is Not Caused by Chromosomal Reciprocal Translocation in Spiny Frog ( Quasipaa boulengeri ). (nih.gov)
  • The formation of sex chromosomes may be reinforced by inhibition of recombination and the accumulation of repetitive DNA sequences. (jove.com)
  • These regions of the chromosome are so dense that they were once thought to be removed from recombination. (duke.edu)
  • Here, in contrast, with several evidences, from classical and molecular cytogenetic analyses, we found 12 sex chromosomes in a Brazilian population of the smoky jungle frog, designated as Leptodactylus pentadactylus Laurenti, 1768 (Leptodactylinae), which has a karyotype with 2 n = 22 chromosomes. (springer.com)
  • and chromosome analysis, in the end determining the fetal karyotype. (scielosp.org)
  • 2. How many total chromosomes are there in the karyotype of a normal human? (study.com)
  • Although human embryonic stem cells (hESC) have been shown to present a stable diploid karyotype 1 , many studies have reported that depending on culture conditions they become prone to acquire chromosomal anomalies such as addition of whole or parts of chromosomes. (jove.com)
  • We have decided to review, using molecular methods, a previously described 7 male true hermaphrodite with a left scrotal testis, oligozoospermia, and no detectable Y chromosome or its fragments on standard karyotype analysis. (bmj.com)
  • There are 47 chromosomes, instead of the usual 46, giving a 47,XYY karyotype. (wikipedia.org)
  • Chromosome classification was based on the numbering system determined by the Committee for a Standardized Karyotype of Rattus noruegzcus (1973). (docme.ru)
  • We investigate yeast sex chromosome evolution by comparing genome sequences from 16 species in the family Saccharomycetaceae, including data from genera Tetrapisispora , Kazachstania , Naumovozyma , and Torulaspora . (pnas.org)
  • The alteration in the location of the chromosomes within the nucleus upon action of internal or external stimuli has been implicated in altering genome function. (jove.com)
  • 10 , the accumulation of multiple chromosomal rearrangements in cell line chromosomes 11 makes them useless for genome mapping. (jove.com)
  • With each translocation, the genome is altered again and again, until you have evolved an entirely new species. (duke.edu)
  • Korenberg J. R. & Rykowski, M. C. Human genome organization: Alu, lines, and the molecular structure of metaphase chromosome bands. (thefullwiki.org)
  • How are organisms able to produce distinct sexes from a single genome? (g3journal.org)
  • the logical choice for anchoring the genome assembly to chromosomes. (g3journal.org)
  • Based on this photomap, we constructed a chromosome-based genome assembly using fluorescent in situ hybridization of PCR-amplified DNA probes. (g3journal.org)
  • genome detected multiple genetic exchanges between pericentromeric regions of chromosomal arms caused by partial-arm translocations. (g3journal.org)
  • This study demonstrates that physical mapping is a powerful tool for correcting errors in draft genome assemblies and for creating chromosome-anchored reference genomes. (g3journal.org)
  • Deletions are when a part of a chromosome is either missing or deleted. (bartleby.com)
  • Deletions of small amounts of genetic material in certain areas of the Y chromosome lead to a condition called Y chromosome infertility. (medlineplus.gov)
  • The deletions occur in areas of the Y chromosome called azoospermia factor (AZF) regions. (medlineplus.gov)
  • In trisomy , for example, there are three copies of one particular chromosome instead of the normal two (one from each parent). (kidshealth.org)
  • An individual who suffers from Down Syndrome, also known as Trisomy 21 would have three copies of chromosome 21 instead of the usual two, resulting in a total of 47 chromosomes. (bartleby.com)
  • Some chromosomes are more likely than others to become unpaired, which can lead to early embryonic demise (chromosomes 13, 16, 18, and 22) or affect term births, such as Down syndrome (trisomy 21). (scrcivf.com)
  • Sometimes, extra copies of chromosome 8 or trisomy 8 may be classified as intermediate risk over unfavorable (see below). (cancer.net)
  • Examples of chromosomal changes that are associated with less successful treatment or with a low chance of curing the AML include extra copies of chromosomes 8 or 13 [for example, trisomy 8 (+8)], deletion of all or part of chromosomes 5 or 7, complex changes on many chromosomes, and changes to chromosome 3 at band q26. (cancer.net)
  • Having an extra chromosome is called trisomy. (cdc.gov)
  • During a Rob translocation, the participating chromosomes break at their centromeres and the long arms fuse to form a single chromosome with a single centromere. (alliedacademies.org)
  • Duke scientists say Cryptococcus swapped chromosome arms at the centromere. (duke.edu)
  • For example, chromosome 1 of C. neoformans contained pieces of four different chromosomes from C. amylolentus, providing evidence of multiple translocations, some within the centromere. (duke.edu)
  • According to their model, multiple translocations deposited the two sex determinants on the same chromosome, with a centromere in between. (duke.edu)
  • The precision necessary to fuse two chromosomes, inactivate one centromere, and adjust the amount of heterochromatin suggests that the chromosomal translocation mechanisms were designed by God to provide for His creatures in this present fallen world. (answersingenesis.org)
  • Until one centromere becomes inactivated the new chromosome will have two active centromeres (dicentric). (thefullwiki.org)
  • Having the centromere located near one end of the chromosome so that one chromosomal arm is long and the other is short. (thefreedictionary.com)
  • of a chromosome) having the centromere closer to one end than the other, resulting in two arms of unequal length. (thefreedictionary.com)
  • The centromere is the region of a chromosome where the two sister chromatids are joined. (infoplease.com)
  • A cis -acting locus ( CE ) within the heterochromatin proximal to the centromere is known to regulate X chromosome elimination. (biologists.org)
  • It thus places the gene near the centromere and the junction of the Rb(6.16)24Lub and Rb(6.15)lAld translocations. (deepdyve.com)
  • A chromosome rearrangement is a structural change in a chromosome such as a deletion, translocation, inversion, or gene amplification. (encyclopedia.com)
  • Sometimes a spontaneous break or breaks occur in a chromosome or chromosomes in a particular cell and can result in a deletion, inversion, or translocation. (encyclopedia.com)
  • If the break or breaks result in the loss of a piece of chromosome, it is called a deletion. (encyclopedia.com)
  • Each time a gene beside MAT is removed by deletion or transposition, the next gene on the chromosome is brought into proximity with MAT and is in turn put at risk for removal. (pnas.org)
  • We propose that the deletion and transposition events are caused by evolutionary accidents during mating-type switching, combined with natural selection to keep MAT and HML on the same chromosome. (pnas.org)
  • An example of disorder caused by deletion is Wolf-Hirschhorn Syndrome which occurs due to partial deletion of the short arm of chromosome 4. (bartleby.com)
  • This subtype causes refractory (treatmentresistant) anemia associated with a deletion of the long arm (q) of chromosome 5, designated "del(5q). (lls.org)
  • However, some are inherited from a parent who carries the translocation balanced by a chromosome deletion. (aafp.org)
  • Phelan-McDermid syndrome (PMS) is a rare genetic condition caused by a deletion or other structural change of the terminal end of chromosome 22 in the 22q13 region or a disease-causing mutation of the SHANK3 gene. (rarediseases.org)
  • A deletion of a part of chromosome that comprises a tumor suppressor gene can add to the transformation of a standard cell into a cancerous cell. (nonamepub.com)
  • Chromosomal defects include missing or extra chromosomes and rearrangement or deletion of parts of chromosomes. (asmscience.org)
  • Missing a small part of a chromosome is called a deletion. (cdc.gov)
  • Thus information about the chronology of DNA replication in structurally abnormal X chromosomes is relevant to the study of the genetic activity of mammalian sex chromosomes. (nature.com)
  • In human females, structurally abnormal X chromosomes, such as deficiencies, duplication/deficiencies or rings, were found to be consistently late-replicating compared with the normal X chromosome 2 . (nature.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)
  • Additional 'chromosome engineering' studies indicate that certain chromosome rearrangements affecting many different chromosomes result in this abnormal replication-timing phenotype, suggesting that all mammalian chromosomes contain discrete cis-acting loci that control proper replication timing of individual chromosomes 5 . (jove.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)
  • PGD has proven that normal appearing pre-embryos frequently can have an abnormal number of chromosomes, rendering them incompatible with the development of a normal pregnancy. (scrcivf.com)
  • Abnormal number or structure of the SEX CHROMOSOMES. (curehunter.com)
  • And when a gene or chromosome is abnormal, it may cause health problems in the body. (chkd.org)
  • X chromosome(s) elimination is achieved by an abnormal anaphase segregation so that X sister chromatids do not reach the poles and are not included in the daughter nuclei. (biologists.org)
  • Oligo-SNP microarray was not performed on my patient, because the chromosome analysis was abnormal. (questdiagnostics.com)
  • The basal lineage of monotremes features an extraordinarily complex sex chromosome system which has provided novel insights into the evolution of mammalian sex chromosomes. (springer.com)
  • Heteromorphic sex chromosomes are common in eukaryotes and largely ubiquitous in birds and mammals. (springer.com)
  • Relatively few amphibian species carry heteromorphic sex chromosomes, and when present, they are frequently represented by only one pair, either XX:XY or ZZ:ZW types. (springer.com)
  • Heteromorphic sex chromosomes have evolved in different animal and plant lineages. (springer.com)
  • with transition rates between homomorphic and heteromorphic sex chromosomes in amphibians appearing roughly equal [but see Hillis and Green (1990) ]. (g3journal.org)
  • There are 23 pairs of chromosomes in humans. (rightdiagnosis.com)
  • Chromosome translocations in peripheral blood lymphocytes of normal, healthy humans increase with age, but the effects of gender, race, and cigarette smoking on background translocation yields have not been examined systematically. (biomedsearch.com)
  • Humans have 23 pairs of chromosomes or a total of 46 chromosomes. (bartleby.com)
  • Rob translocation homozygosity could be seen as a potential speciation in humans with 44 chromosomes. (alliedacademies.org)
  • Translocation between chromosomes 13 and 14 is the most frequent one in humans, estimated to be approximately 75% of all Rob translocations. (alliedacademies.org)
  • The X chromosome is one of the two sex chromosomes in humans (the other is the Y chromosome). (medlineplus.gov)
  • The results of these studies show that the female md rats (mdr) are examples of X-chromosome monosomy, comparable to Turner's syndrome in humans, and that the neurological and neuropathological defects in these animals are comparable to those in hemizygous male littermates (Dentinger et al. (docme.ru)
  • In humans, there are a total of 46 chromosomes in the nucleus of a somatic cell. (biology-online.org)
  • Chromosomes come in pairs and humans have 46 chromosomes, in 23 pairs. (cdc.gov)
  • However, repetitive sequences of these ZW chromosome pairs differed among species. (jove.com)
  • These results suggest that the W chromosome sequences were not conserved between gouldii and acanthurus clades and that these repetitive sequences have been amplified rapidly and independently on the W chromosome of the two clades after their divergence. (jove.com)
  • Find this article online O'Keefe RT, Henderson SC, Spector DL (1992) Dynamic organization of DNA replication in mammalian cell nuclei: Spatially and temporally defined replication of chromosome-specific alpha-satellite DNA sequences. (thefullwiki.org)
  • For example, in female mammalian cells one of the two X chromosomes becomes late replicating through a process known as X inactivation 1 . (jove.com)
  • In addition, a discrete cis-acting locus, known as the X inactivation center, regulates this X inactivation process, including the induction of delayed replication timing on the entire inactive X chromosome. (jove.com)
  • 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)
  • During evolution of sex chromosomes in placental mammals, the degradation of the Y chromosome and inactivation spreading along the X chromosome occurred gradually and in concert. (deepdyve.com)
  • A number of hypotheses are considered on evolutionary relationships of X-chromosome inactivation and other molecular processes in mammals. (deepdyve.com)
  • Asynapsis of these arms and the persistent DSBs then trigger transcriptional silencing through meiotic sex chromosome inactivation (MSCI), resulting in formation of the XY body. (biomedcentral.com)
  • Stage-specific expression profiling of Drosophila spermatogenesis suggests that meiotic sex chromosome inactivation drives genomic relocation of te. (nih.gov)
  • Any zygote that forms with only one copy of chromosome 21 has a very severe version of the problems of Down's syndrome. (abpischools.org.uk)
  • The best-known chromosomal disease is probably Down syndrome, caused by an extra copy of chromosome 21. (asmscience.org)
  • For example, people with Down syndrome have an extra copy of chromosome 21. (cdc.gov)
  • In order to elucidate a possible evolutionary origin of this chromosome 1, studies of genomic synteny were carried out with eight fish species. (mdpi.com)
  • In some lineages, sex chromosomes have been conserved (for example, the XY sex chromosomes in therian mammals and the ZW in birds), while different sex chromosomes have evolved in closely related insect, fish, and reptile species (except birds) (Ming et al. (springer.com)
  • The pseudoautosomal region and sex chromosome aneuploidies in domestic species. (semanticscholar.org)
  • It is an ordinary paired chromosome that is the same in both sexes of a species. (rightdiagnosis.com)
  • This is the case of Ronderosia bergii , in which further large pericentromeric inversion in the neo-Y also took place, making this species particularly interesting for investigating sex chromosome evolution. (nature.com)
  • Here, we characterized the satellite DNAs (satDNAs) and transposable elements (TEs) of the species to investigate the quantitative differences in repeat composition between male and female genomes putatively associated with sex chromosomes. (nature.com)
  • This X-autosome translocation differs from the other evolutionary X-autosome translocations known in certain species of Drosophila . (ias.ac.in)
  • We applied C-banding and comparative genomic hybridization to reveal that these species have ZZ/ZW sex micro-chromosomes in which the W chromosome is highly differentiated from the Z chromosome. (jove.com)
  • In combination with previous reports, all six Varanus species in which sex chromosomes have been identified have ZZ/ZW sex chromosomes, spanning several clades on the varanid phylogeny, making it likely that the ZZ/ZW sex chromosome is ancestral for this family. (jove.com)
  • Furthermore, the W chromosome probe for V. acanthurus produced hybridization signals only on the centromeric regions of W chromosomes of the other two species. (jove.com)
  • Mitotic chromosome preparation for these two species had previously been limited to brain ganglia and cell lines. (jove.com)
  • DURHAM, NC -- Biologically speaking, nearly every species on Earth has two opposite sexes, male and female. (duke.edu)
  • Regardless of the name or species, Heitman contends that some universal principles could govern the evolution of all sex chromosomes. (duke.edu)
  • The result was an organism with a bipolar mating system, much like the male and female sexes that embody most species. (duke.edu)
  • A limited number of mammal species have, however, evolved to escape convention and present aberrant sex chromosome complements. (sun.ac.za)
  • In contrast to well-studied mammalian and avian systems, many organisms exhibit homomorphic sex chromosomes that cannot be diagnosed cytogenetically, making it difficult to determine sex chromosome homology among species. (g3journal.org)
  • We decided to investigate the role of chromatin structural changes in sex chromosome emergence by using a basal metazoan species harboring a ZW system, the acoelomate Schistosoma mansoni . (biomedcentral.com)
  • An inversion results when a segment of chromosome breaks off, is reversed (inverted), and is reinserted into its original location. (encyclopedia.com)
  • When it is large, the outcome is the formation of an inversion loop involving the majority of the chromosome. (nonamepub.com)
  • An inversion is when part of a chromosome has been flipped over. (cdc.gov)
  • The natural banding pattern of polytene and mitotic chromosomes provides guidance for the precise ordering and orientation of the genomic supercontigs. (jove.com)
  • Screening for normal chromosome pairing is done using a technique called fluorescent in situ hybridization (FISH) or comparative genomic hybridization. (scrcivf.com)
  • We tested hypotheses of male- or female-heterogamety by sequencing hundreds of thousands of anonymous genomic regions in a panel of known-sex cryptobranchids and characterized patterns of presence/absence, inferred zygosity, and depth of coverage to identify sex-linked regions of these 56 gigabase genomes. (g3journal.org)
  • To elucidate the mechanisms that led to the emergence of sex chromosomes, we compared the genomic sequence and the chromatin structure of male and female individuals. (biomedcentral.com)
  • These findings allowed to trace an evolutionary trend for the large metacentric chromosome of S. senegalensis, throughout different rearrangements, which could be at an initial phase of differentiation as sex chromosome. (mdpi.com)
  • Chromosome rearrangements can contribute to the transformation of a normal cell into a cancerous cell and are therefore found in many cancer cells. (encyclopedia.com)
  • In addition, this method allows for the unambiguous identification of chromosomal rearrangements that correlate with changes in replication timing that affect the entire chromosome. (jove.com)
  • In addition, because the method described here evaluates single cells, it can detect changes in chromosome replication timing on chromosomal rearrangements that are present in only a fraction of the cells in a population. (jove.com)
  • Certain kinds of chromosome rearrangements are found more commonly in cancers of specific sorts of cells. (nonamepub.com)
  • These data indicate that the combined X and Y tiling path arrays provide an effective tool for the investigation and diagnosis of sex chromosome copy number aberrations and rearrangements. (bmj.com)
  • 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)
  • Here, we present a method for the quantitative analysis of chromosome replication timing combined with fluorescent in situ hybridization. (jove.com)
  • After conception (when a sperm cell and an egg come together to make a baby), the chromosomes duplicate again and again to pass on the same genetic information to each new cell in the developing child. (kidshealth.org)
  • Each cell of the body, except for the egg and the sperm cells, contains 23 pairs of chromosomes and 46 chromosomes in total. (encyclopedia.com)
  • The egg and sperm cells each contain 23 chromosomes. (encyclopedia.com)
  • An individual with an X chromosome that carries the SRY gene will develop as a male despite not having a Y chromosome, but will not be able to produce sperm to father biological children. (medlineplus.gov)
  • As a result, sperm develop abnormally or do not develop at all, leading to Y chromosome infertility. (medlineplus.gov)
  • If one of these atypical sperm cells contributes to the genetic makeup of a child, the child will have an extra Y-chromosome in each of the body's cells. (wikipedia.org)
  • A human germ cell has one sex chromosome: X or Y in a sperm and X in an egg. (novapublishers.com)
  • When an X-sperm is combined with an egg, the resulting zygote (fertilized egg) will contain two X chromosomes. (novapublishers.com)
  • Combination of a Y-sperm and an egg will produce a male.Usually, a woman has two X chromosomes (XX) and a man one X and one Y (XY). (novapublishers.com)
  • This final separation reduces the chromosome number by one-half, creating the haploid sperm and egg. (infoplease.com)
  • Along with the development of ICSI in 1993, our center was the first to study the Y chromosome and male infertility , and why tiny amounts of sperm are often found in the testes of azoospermic men previously thought to be making no sperm. (infertile.com)
  • We show that reduced MAD2 levels attenuate the apoptotic response to mis-segregating sex chromosomes and allow the formation of aneuploid sperm. (biologists.org)
  • The essential role of the Spam1 sperm antigen in mouse sperm-egg interactions and its gene location provide strong support for its candidacy as the gene involved in the dysfunction of mouse sperm bearing the Rb(6.16)24Lub or Rb(6.15)1Ald translocation. (deepdyve.com)
  • In monosomy , another form of numerical error, one member of a chromosome pair is missing. (kidshealth.org)
  • Turner Syndrome only occurs in women and is caused by monosomy X, which is an absence of that entire sex chromosome, leaving only 45 chromosomes. (bartleby.com)
  • X-chromosome monosomy in the myelin-deficient rat mutant. (docme.ru)
  • The myelin-deficient rat is useful for studies of X-chromosome monosomy since XO females can readily be identified by the neurological syndrome characteristic of the md mutation. (docme.ru)
  • If you have only one copy of a chromosome it is known as monosomy. (abpischools.org.uk)
  • Missing a chromosome is called monosomy. (cdc.gov)
  • Haldane's rule states that in organisms with differentiated sex chromosomes, hybrid sterility or inviability is generally expressed more frequently in the heterogametic sex. (genetics.org)
  • The chromosomes found only in the heterogametic sex (the Y and the W) are degraded versions of the homogametic chromosomes (the X and the Z, respectively). (scienceblogs.com)
  • This is referred to as reciprocal translocation, and this particular one is commonly expressed as t(15;17). (labcorp.com)
  • Up to 98% of cases of acute promyelocytic leukemia have a characteristic t(15;17) PML-RARA reciprocal chromosomal translocation. (labcorp.com)
  • Other sex chromosome aberrations were found in 1 per 11,637 children. (nih.gov)
  • We have developed a human X and Y chromosome tiling path array for the analysis of sex chromosome aberrations. (bmj.com)
  • In females heterozygous for Searle's translocation ( T 16 H ), in which part of the X chromosome is translocated on to an unidentified autosome, the sex-linked variegation is suppressed. (nature.com)
  • Ohno and Lyon 5 later reported that the normal X of heterozygous females carrying the translocation showed positive heteropycnosis in 90 per cent of somatic prophases. (nature.com)
  • 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)
  • 46,XX testicular disorder of sex development is a condition in which individuals with two X chromosomes in each cell, the pattern normally found in females, have a male appearance. (medlineplus.gov)
  • For those agricultural pests in which females cause no damage, sex separation systems are not essential, but highly desirable in terms of increased efficiency. (biomedcentral.com)
  • The risk associated with the release of contaminating CI females thus makes either female sterilization or the need for stringent, if not absolute, sex separation approaches even more critical. (biomedcentral.com)
  • In a study appearing early online Aug. 11 in PLOS Biology , Duke researchers have mapped the evolutionary turning point that transformed the pathogenic form of Cryptococcus from an organism of many sexes to one with only two. (duke.edu)
  • However, in other lineages, sex chromosomes are much harder to diagnose and appear to be much more labile over evolutionary timescales. (g3journal.org)
  • Due to an X-autosome translocation, S. delicatus has an XY1Y2 sex chromosome system, rare in mammals. (wikipedia.org)
  • The authors compare snake sex chromosome evolution with that of mammals and birds. (scienceblogs.com)
  • Because the Y chromosomes don't determine sex in Drosophila , the implications of missing or extra chromosomes are different than in mammals. (scienceblogs.com)
  • In placental mammals, the X and Y chromosomes share homology only in the pseudoautosomal regions (PAR). (biomedcentral.com)
  • All therian mammals (eutherians and marsupials) have an XX female/XY male sex chromosome system or some variant of it. (sun.ac.za)
  • 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)
  • PGD can also help screen the embryo for single gene disorders (SGA) such as cystic fibrosis, Tay-Sachs disease, Duchenne muscular dystrophy, sickle cell anemia and X-chromosome-linked disorders. (scrcivf.com)
  • Examples of hereditary conditions caused by gene disorders are cystic fibrosis, Tay-Sachs disease, Duchenne muscular dystrophy, sickle cell anemia and X-chromosome-linked disorders. (scrcivf.com)
  • Genetic disorders often are described in terms of the chromosome that contains the gene that is changed in people who have the disorder. (cdc.gov)
  • Some disorders are caused by having a different number of sex chromosomes. (cdc.gov)
  • In the mouse, all chromosomes are acrocentric, and the PAR localizes at the tip of the long q arm of the sex chromosomes. (biomedcentral.com)
  • An autosome complement consists of 29 pairs of single-armed ( acrocentric ) chromosomes that gradually decrease in size (NN 1-29). (thefreedictionary.com)
  • Carriers of translocations of relatively small chromosomal regions onto an acrocentric short arm may have a very high risk of having unbalanced offspring (3, 4). (thefreedictionary.com)
  • Acrocentric chromosomes are the main origin of sSMCs and chromosome 15 is the most frequent origin of de novo cases that contains 50% of acrocentric chromosomes-originated sSMCs. (thefreedictionary.com)
  • 3] This raises the prospect of determining the familial transmission of individual acrocentric chromosomes. (thefreedictionary.com)
  • The most typical example of X p elimination is represented in Fig. 1 where, at anaphase stage, the two acrocentric X p chromosomes are seen undivided at the equatorial plate, in contrast to the rest of the chromosomes already at the poles ( Dubois, 1932 ). (biologists.org)
  • These results imply differential amplification of satDNAs on neo-Y chromosome and a minor role of TEs in sex chromosome differentiation. (nature.com)
  • In this study, the researchers showed that in Cryptococcus amylolentus, the ancestral state, the P/R locus resided on chromosome 10 and the HD locus on chromosome 11. (duke.edu)
  • Translocations involving the immunoglobulin heavy chain locus (IGH) are hallmarks of mature B-cell malignancies, where they drive pathogenesis. (ncl.ac.uk)
  • A condition known as mosaicism results from an error in the distribution of chromosomes between daughter cells during an early embryonic cell division, producing two and sometimes three populations of cells with different chromosome numbers in the same individual. (thefreedictionary.com)
  • Mosaicism involving the sex chromosomes is not uncommon. (thefreedictionary.com)
  • A human somatic cell has two sex chromosomes: XY in male and XX in female. (novapublishers.com)
  • The precise cellular/molecular mechanisms underlying the differential segregation behaviour of Sciara chromosomes during X p somatic elimination have not been conclusively elucidated. (biologists.org)
  • Alternate segregation is dominant in the different types of Rob translocations. (alliedacademies.org)
  • All other segregation modes (adjacent-1, adjacent-2, 3:0) produce unbalanced gametes with disomies and nullisomies of chromosomes involved in Rob translocations. (alliedacademies.org)
  • Importantly, the eliminating X chromosomes show a retardation in anaphase chromatid segregation and high levels of H3S10 phosphorylation in the chromosome arms. (biologists.org)
  • Sex chromosome mis-segregation is particularly common and can lead to sterility or to aneuploid offspring (e.g. individuals with Turner or Klinefelter syndrome). (biologists.org)
  • These physical connections between each homolog pair are essential for correct homolog alignment at metaphase, and for the fidelity of chromosome segregation. (biologists.org)
  • Homologs without a crossover (non-exchange chromosomes) are at risk for mis-segregation. (biologists.org)
  • Human chromosomes are large enough to be seen with a high-powered microscope, and the 23 pairs can be identified according to differences in their size, shape, and the way they pick up special laboratory dyes. (kidshealth.org)
  • This is the fourth edition of an acclaimed introductory textbook on the structure and function of human chromosomes. (springer.com)
  • Proliferating normal human dermal fibroblasts were subjected to standard a two-dimensional FISH to delineate territories for all human chromosomes. (jove.com)
  • The sex chromosomes form one of the 23 pairs of human chromosomes in each cell. (medlineplus.gov)
  • While a parent with a balanced translocation may be physically normal, a child may receive either too much or too little genetic information. (southwestvasectomyreversal.com)
  • A parent with a balanced translocation is healthy, but he or she may be at risk for passing on unbalanced chromosomes to a child. (chkd.org)
  • A benefit of understanding the Y chromosome is it will help us to comprehend why men who are seemingly azoospermic usually have some residual tiny amount of spermatogenesis that can be used for successful ICSI . (infertile.com)
  • Drosophila nasuta albomicans (with 2n = 6), contains a pair of metacentric neo-sex chromosomes. (ias.ac.in)
  • Sometimes, a translocation occurs and there's no additional genetic material in the cell. (brighthub.com)
  • The genetic material from the additional 21 chromosome is the thing that causes the health issues that are due to Down syndrome. (nonamepub.com)
  • This is when a person has 2 or more sets of chromosomes in his or her cells with different genetic material. (chkd.org)
  • It is a specific rearrangement of genetic material from two separate chromosomes (chromosomal translocation) and is associated with a specific type of leukemia. (labcorp.com)
  • The human metacentric X and Y chromosomes have two PARs, one on each end of the sex chromosomes. (biomedcentral.com)
  • article{205469, abstract = {XX maleness is the most common condition in which testes develop in the absence of a cytogenetically detectable Y chromosome. (ugent.be)
  • Sometimes a small segment of chromosome is amplified, which results in the presence of multiple copies of that section of the chromosome. (encyclopedia.com)
  • It means that most cells in the body will have three copies of this chromosome, instead of the usual two. (brighthub.com)
  • When this combines with another gamete, that has the usual complement of one chromosome 13, the result is a zygote with three copies of the chromosome. (brighthub.com)
  • The following chromosomal conditions are associated with changes in the structure or number of copies of x chromosome. (medlineplus.gov)
  • 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)
  • The following chromosomal conditions are associated with changes in the structure or number of copies of y chromosome. (medlineplus.gov)
  • They can be caused by missing or extra copies of the sex chromosomes or by structural changes in these chromosomes. (medlineplus.gov)
  • When two chromatids do not separate during a meiotic division, resulting in one gamete with two copies of the chromosomes and another with no copies. (abpischools.org.uk)
  • When an individual has more than the normal number of copies of a particular chromosome. (abpischools.org.uk)
  • This can result in one daughter cell with two copies of a chromosome and another with none. (abpischools.org.uk)
  • If you have more copies than normal of a chromosome it is known as polysomy. (abpischools.org.uk)
  • Chromosome 21: Non-disjunction of chromosome 21 can give an individual three copies of the chromosome. (abpischools.org.uk)
  • Cells contain 3 copies of the 21st chromosome. (chkd.org)
  • Sometimes, chromosomes can break apart and attach to other chromosomes, a condition known as translocation. (scrcivf.com)
  • During meiotic prophase, a male's X and two Y chromosomes form a trivalent. (wikipedia.org)
  • During mitosis, DNA is condensed into visible chromosomes (prophase) that arrange at the cell midplane (metaphase), separate (anaphase), and decondense into the interphase. (thefullwiki.org)
  • In addition to physical mapping, the developed technique can be applied to population cytogenetics and chromosome taxonomy/systematics of mosquitoes and other insect groups. (jove.com)
  • Among the three mosquito genera, namely Anopheles , Aedes, and Culex , a well-established chromosome-based mapping technique has been developed only for Anopheles , whose members possess readable polytene chromosomes 1 . (jove.com)
  • In S. coprophila polytene chromosomes, both proteins associate to the pericentromeric regions and to the heterochromatic subterminal bands of the chromosomes. (semanticscholar.org)
  • In this study, we developed a high-resolution cytogenetic photomap with completely straightened polytene chromosomes from the salivary glands of the mosquito larvae. (g3journal.org)
  • In some cases, the addition of an extra Y-chromosome results from nondisjunction during cell division during a post-zygotic mitosis in early embryonic development. (wikipedia.org)
  • Like mitosis, in metaphase II the chromosomes line up along the cell equator, and the paired chromatids separate in anaphase II. (infoplease.com)
  • Down Syndrome), translocations (incorrect chromosome position), or other structural alterations that may be clinically significant. (nccrm.com)
  • This inactive state is partially maintained in post-meiotic haploid spermatids (postmeiotic sex chromatin repression, PSCR). (biomedcentral.com)
  • Prior to cell divisions, the chromosomes in the nucleus appear as threadlike strands (called [[chromatin]]s). (biology-online.org)
  • Chromatin The network of chromosomes, histones, and other proteins found in the eukaryotic nucleus during interphase. (thefullwiki.org)
  • Our study provides for the first time evidence for the hypothesis that, at least in organisms with a ZW type of sex chromosomes, repeat-induced chromatin structure changes could indeed be the initial event in sex chromosome emergence. (biomedcentral.com)
  • The karyotypes of monitor lizards are known to be highly conserved yet the sex chromosomes in this family have not been fully investigated. (jove.com)