Chromosomes: 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)Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Chromosome Banding: 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.X 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.Chromosome Aberrations: Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.Sex Chromosomes: 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)Chromosomes, Human, Pair 1: A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.Chromosomes, Human: 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.Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Chromosome Segregation: The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.Chromosomes, Human, Pair 7: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 11: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 17: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 6: A specific pair GROUP C CHROMSOMES of the human chromosome classification.Chromosome Deletion: Actual loss of portion of a chromosome.Chromosomes, Human, Pair 9: A specific pair of GROUP C CHROMSOMES of the human chromosome classification.Chromosomes, Human, Pair 21: A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.Chromosomes, Plant: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.Chromosomes, Fungal: Structures within the nucleus of fungal cells consisting of or containing DNA, which carry genetic information essential to the cell.Chromosomes, Human, 6-12 and X: 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.Chromosomes, Human, Pair 2: A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.Chromosomes, Human, Pair 16: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 22: A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.Chromosome Pairing: The alignment of CHROMOSOMES at homologous sequences.Chromosomes, Mammalian: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of MAMMALS.Chromosomes, Human, Pair 13: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 4: A specific pair of GROUP B CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 10: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Y: The human male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans.Chromosomes, Human, Pair 8: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 19: A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.Chromosome Disorders: 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)Chromosomes, Artificial, Bacterial: 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.Chromosomes, Human, X: The human female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in humans.Chromosomes, Human, 1-3: The large, metacentric human chromosomes, called group A in the human chromosome classification. This group consists of chromosome pairs 1, 2, and 3.Chromosomes, Human, Pair 12: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosome Painting: 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.Chromosomes, Human, Pair 5: One of the two pairs of human chromosomes in the group B class (CHROMOSOMES, HUMAN, 4-5).Chromosomes, Human, Pair 15: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Karyotyping: Mapping of the KARYOTYPE of a cell.Chromosomes, Human, Pair 14: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 18: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.Chromosomes, Human, 16-18: The short, submetacentric human chromosomes, called group E in the human chromosome classification. This group consists of chromosome pairs 16, 17, and 18.In Situ Hybridization, Fluorescence: 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.Chromosomes, Human, Pair 20: A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.Chromosomes, Artificial, Yeast: 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.Chromosomes, Human, 13-15: The medium-sized, acrocentric human chromosomes, called group D in the human chromosome classification. This group consists of chromosome pairs 13, 14, and 15.Genetic Linkage: The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.Chromosome Breakage: A type of chromosomal aberration involving DNA BREAKS. Chromosome breakage can result in CHROMOSOMAL TRANSLOCATION; CHROMOSOME INVERSION; or SEQUENCE DELETION.Chromosomes, Human, 21-22 and Y: 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.Ring Chromosomes: Aberrant chromosomes with no ends, i.e., circular.Chromosome Inversion: 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.Genetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.Chromosome Positioning: The mechanisms of eukaryotic CELLS that place or keep the CHROMOSOMES in a particular SUBNUCLEAR SPACE.Chromosomes, Human, 4-5: The large, submetacentric human chromosomes, called group B in the human chromosome classification. This group consists of chromosome pairs 4 and 5.Molecular Sequence Data: 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.X Chromosome Inactivation: 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.Centromere: 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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Chromosomes, Insect: Structures within the CELL NUCLEUS of insect cells containing DNA.Translocation, Genetic: A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.Meiosis: 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.Hybrid Cells: 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.Chromosome Structures: Structures which are contained in or part of CHROMOSOMES.Chromosomes, Human, 19-20: The short, metacentric human chromosomes, called group F in the human chromosome classification. This group consists of chromosome pairs 19 and 20.Aneuploidy: 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).Metaphase: 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.Mitosis: 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.Recombination, Genetic: 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.Lod Score: The total relative probability, expressed on a logarithmic scale, that a linkage relationship exists among selected loci. Lod is an acronym for "logarithmic odds."Pedigree: 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.Crosses, Genetic: 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.Mutation: 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.Microsatellite Repeats: 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).Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Cloning, Molecular: 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.Trisomy: The possession of a third chromosome of any one type in an otherwise diploid cell.Nondisjunction, Genetic: 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.Chromosomes, Artificial, Human: 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.Kinetochores: Large multiprotein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase in the cell cycle.Nucleic Acid Hybridization: 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)Telomere: 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.DNA: 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).Chromosome Walking: 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.Chromosomal Proteins, Non-Histone: 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.Amino Acid Sequence: 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.Chromosomal Instability: An increased tendency to acquire CHROMOSOME ABERRATIONS when various processes involved in chromosome replication, repair, or segregation are dysfunctional.Spindle Apparatus: A microtubule structure that forms during CELL DIVISION. It consists of two SPINDLE POLES, and sets of MICROTUBULES that may include the astral microtubules, the polar microtubules, and the kinetochore microtubules.Blotting, Southern: 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.Models, Genetic: 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.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Chromosome Fragility: Susceptibility of chromosomes to breakage leading to translocation; CHROMOSOME INVERSION; SEQUENCE DELETION; or other CHROMOSOME BREAKAGE related aberrations.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Quantitative Trait Loci: Genetic loci associated with a QUANTITATIVE TRAIT.Haplotypes: 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.Chromosome Duplication: An aberration in which an extra chromosome or a chromosomal segment is made.DNA, Satellite: 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.DNA Probes: Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.Polymerase Chain Reaction: 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.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.Genes: 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.Repetitive Sequences, Nucleic Acid: 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).Diploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Chromatids: Either of the two longitudinally adjacent threads formed when a eukaryotic chromosome replicates prior to mitosis. The chromatids are held together at the centromere. Sister chromatids are derived from the same chromosome. (Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Mosaicism: 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.Heterozygote: An individual having different alleles at one or more loci regarding a specific character.Abnormalities, MultiplePolytene Chromosomes: Extra large CHROMOSOMES, each consisting of many identical copies of a chromosome lying next to each other in parallel.Multigene Family: 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)Polyploidy: The chromosomal constitution of a cell containing multiples of the normal number of CHROMOSOMES; includes triploidy (symbol: 3N), tetraploidy (symbol: 4N), etc.DNA Replication: The process by which a DNA molecule is duplicated.Gene Deletion: 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.Prophase: 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.Interphase: The interval between two successive CELL DIVISIONS during which the CHROMOSOMES are not individually distinguishable. It is composed of the G phases (G1 PHASE; G0 PHASE; G2 PHASE) and S PHASE (when DNA replication occurs).Gene Dosage: 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.Loss of Heterozygosity: The loss of one allele at a specific locus, caused by a deletion mutation; or loss of a chromosome from a chromosome pair, resulting in abnormal HEMIZYGOSITY. It is detected when heterozygous markers for a locus appear monomorphic because one of the ALLELES was deleted.Cell Cycle Proteins: Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.DNA-Binding Proteins: 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.Genome, Human: The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.Cytogenetic Analysis: 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.Genetic Variation: Genotypic differences observed among individuals in a population.Cytogenetics: 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.Karyotype: 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)Nuclear Proteins: 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.Polymorphism, Genetic: 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.Cosmids: Plasmids containing at least one cos (cohesive-end site) of PHAGE LAMBDA. They are used as cloning vehicles.Chromosome Fragile Sites: Specific loci that show up during KARYOTYPING as a gap (an uncondensed stretch in closer views) on a CHROMATID arm after culturing cells under specific conditions. These sites are associated with an increase in CHROMOSOME FRAGILITY. They are classified as common or rare, and by the specific culture conditions under which they develop. Fragile site loci are named by the letters "FRA" followed by a designation for the specific chromosome, and a letter which refers to which fragile site of that chromosome (e.g. FRAXA refers to fragile site A on the X chromosome. It is a rare, folic acid-sensitive fragile site associated with FRAGILE X SYNDROME.)Gene Rearrangement: The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.Chromatin: 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.Sex Chromosome Disorders: 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).Monosomy: The condition in which one chromosome of a pair is missing. In a normally diploid cell it is represented symbolically as 2N-1.Plasmids: 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.Spermatocytes: 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.Genes, X-Linked: Genes that are located on the X CHROMOSOME.Sequence Tagged Sites: Short tracts of DNA sequence that are used as landmarks in GENOME mapping. In most instances, 200 to 500 base pairs of sequence define a Sequence Tagged Site (STS) that is operationally unique in the human genome (i.e., can be specifically detected by the polymerase chain reaction in the presence of all other genomic sequences). The overwhelming advantage of STSs over mapping landmarks defined in other ways is that the means of testing for the presence of a particular STS can be completely described as information in a database.Polymorphism, Restriction Fragment Length: Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Genes, Dominant: Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.Species Specificity: 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.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Polymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.DNA Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.Genetic Predisposition to Disease: A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.Philadelphia Chromosome: An aberrant form of human CHROMOSOME 22 characterized by translocation of the distal end of chromosome 9 from 9q34, to the long arm of chromosome 22 at 22q11. It is present in the bone marrow cells of 80 to 90 per cent of patients with chronic myelocytic leukemia (LEUKEMIA, MYELOGENOUS, CHRONIC, BCR-ABL POSITIVE).Genes, Recessive: Genes that influence the PHENOTYPE only in the homozygous state.Azure Stains: PHENOTHIAZINES with an amino group at the 3-position that are green crystals or powder. They are used as biological stains.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Chromosomes, Archaeal: Structures within the nucleus of archaeal cells consisting of or containing DNA, which carry genetic information essential to the cell.Sequence Homology, Nucleic Acid: 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.Chromosome Breakpoints: The locations in specific DNA sequences where CHROMOSOME BREAKS have occurred.Contig Mapping: Overlapping of cloned or sequenced DNA to construct a continuous region of a gene, chromosome or genome.Cell Nucleus: 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)Genome: The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.Ploidies: The degree of replication of the chromosome set in the karyotype.Homozygote: An individual in which both alleles at a given locus are identical.Haploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented once. Symbol: N.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Escherichia coli: 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.Genetic Loci: 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.DNA Primers: 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.Sex Chromatin: 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)Genomic Imprinting: The variable phenotypic expression of a GENE depending on whether it is of paternal or maternal origin, which is a function of the DNA METHYLATION pattern. Imprinted regions are observed to be more methylated and less transcriptionally active. (Segen, Dictionary of Modern Medicine, 1992)Gene Duplication: Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.Hybridization, Genetic: The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.Gene Amplification: A selective increase in the number of copies of a gene coding for a specific protein without a proportional increase in other genes. It occurs naturally via the excision of a copy of the repeating sequence from the chromosome and its extrachromosomal replication in a plasmid, or via the production of an RNA transcript of the entire repeating sequence of ribosomal RNA followed by the reverse transcription of the molecule to produce an additional copy of the original DNA sequence. Laboratory techniques have been introduced for inducing disproportional replication by unequal crossing over, uptake of DNA from lysed cells, or generation of extrachromosomal sequences from rolling circle replication.Drosophila: 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.Genes, Lethal: Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Intellectual Disability: Subnormal intellectual functioning which originates during the developmental period. This has multiple potential etiologies, including genetic defects and perinatal insults. Intelligence quotient (IQ) scores are commonly used to determine whether an individual has an intellectual disability. IQ scores between 70 and 79 are in the borderline range. Scores below 67 are in the disabled range. (from Joynt, Clinical Neurology, 1992, Ch55, p28)Genes, Bacterial: The functional hereditary units of BACTERIA.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.DNA, Neoplasm: DNA present in neoplastic tissue.Chromosomes, Artificial: 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.Sister Chromatid Exchange: An exchange of segments between the sister chromatids of a chromosome, either between the sister chromatids of a meiotic tetrad or between the sister chromatids of a duplicated somatic chromosome. Its frequency is increased by ultraviolet and ionizing radiation and other mutagenic agents and is particularly high in BLOOM SYNDROME.Syndrome: A characteristic symptom complex.Pachytene Stage: The stage in the first meiotic prophase, following ZYGOTENE STAGE, when CROSSING OVER between homologous CHROMOSOMES begins.Microtubules: Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Exons: The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.Histones: 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.DNA, Fungal: Deoxyribonucleic acid that makes up the genetic material of fungi.Genes, Y-Linked: Genes that are located on the Y CHROMOSOME.Euchromatin: Chromosome regions that are loosely packaged and more accessible to RNA polymerases than HETEROCHROMATIN. These regions also stain differentially in CHROMOSOME BANDING preparations.Triticum: A plant genus of the family POACEAE that is the source of EDIBLE GRAIN. A hybrid with rye (SECALE CEREALE) is called TRITICALE. The seed is ground into FLOUR and used to make BREAD, and is the source of WHEAT GERM AGGLUTININS.Genes, Tumor Suppressor: Genes that inhibit expression of the tumorigenic phenotype. They are normally involved in holding cellular growth in check. When tumor suppressor genes are inactivated or lost, a barrier to normal proliferation is removed and unregulated growth is possible.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.Aurora Kinases: A family of highly conserved serine-threonine kinases that are involved in the regulation of MITOSIS. They are involved in many aspects of cell division, including centrosome duplication, SPINDLE APPARATUS formation, chromosome alignment, attachment to the spindle, checkpoint activation, and CYTOKINESIS.Sex Determination Processes: The mechanisms by which the SEX of an individual's GONADS are fixed.Down Syndrome: A chromosome disorder associated either with an extra chromosome 21 or an effective trisomy for chromosome 21. Clinical manifestations include hypotonia, short stature, brachycephaly, upslanting palpebral fissures, epicanthus, Brushfield spots on the iris, protruding tongue, small ears, short, broad hands, fifth finger clinodactyly, Simian crease, and moderate to severe INTELLECTUAL DISABILITY. Cardiac and gastrointestinal malformations, a marked increase in the incidence of LEUKEMIA, and the early onset of ALZHEIMER DISEASE are also associated with this condition. Pathologic features include the development of NEUROFIBRILLARY TANGLES in neurons and the deposition of AMYLOID BETA-PROTEIN, similar to the pathology of ALZHEIMER DISEASE. (Menkes, Textbook of Child Neurology, 5th ed, p213)Genes, Insect: The functional hereditary units of INSECTS.DNA, Complementary: Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.Meiotic Prophase I: 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.Quantitative Trait, Heritable: A characteristic showing quantitative inheritance such as SKIN PIGMENTATION in humans. (From A Dictionary of Genetics, 4th ed)Radiation Hybrid Mapping: A method for ordering genetic loci along CHROMOSOMES. The method involves fusing irradiated donor cells with host cells from another species. Following cell fusion, fragments of DNA from the irradiated cells become integrated into the chromosomes of the host cells. Molecular probing of DNA obtained from the fused cells is used to determine if two or more genetic loci are located within the same fragment of donor cell DNA.Gene Library: A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.Genetic Heterogeneity: The presence of apparently similar characters for which the genetic evidence indicates that different genes or different genetic mechanisms are involved in different pedigrees. In clinical settings genetic heterogeneity refers to the presence of a variety of genetic defects which cause the same disease, often due to mutations at different loci on the same gene, a finding common to many human diseases including ALZHEIMER DISEASE; CYSTIC FIBROSIS; LIPOPROTEIN LIPASE DEFICIENCY, FAMILIAL; and POLYCYSTIC KIDNEY DISEASES. (Rieger, et al., Glossary of Genetics: Classical and Molecular, 5th ed; Segen, Dictionary of Modern Medicine, 1992)DNA Restriction Enzymes: Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.Sex Chromosome Disorders of Sex Development: Congenital conditions of atypical sexual development associated with abnormal sex chromosome constitutions including MONOSOMY; TRISOMY; and MOSAICISM.

The nuclear receptor superfamily has undergone extensive proliferation and diversification in nematodes. (1/6287)

The nuclear receptor (NR) superfamily is the most abundant class of transcriptional regulators encoded in the Caenorhabditis elegans genome, with >200 predicted genes revealed by the screens and analysis of genomic sequence reported here. This is the largest number of NR genes yet described from a single species, although our analysis of available genomic sequence from the related nematode Caenorhabditis briggsae indicates that it also has a large number. Existing data demonstrate expression for 25% of the C. elegans NR sequences. Sequence conservation and statistical arguments suggest that the majority represent functional genes. An analysis of these genes based on the DNA-binding domain motif revealed that several NR classes conserved in both vertebrates and insects are also represented among the nematode genes, consistent with the existence of ancient NR classes shared among most, and perhaps all, metazoans. Most of the nematode NR sequences, however, are distinct from those currently known in other phyla, and reveal a previously unobserved diversity within the NR superfamily. In C. elegans, extensive proliferation and diversification of NR sequences have occurred on chromosome V, accounting for > 50% of the predicted NR genes.  (+info)

Analysis of two cosmid clones from chromosome 4 of Drosophila melanogaster reveals two new genes amid an unusual arrangement of repeated sequences. (2/6287)

Chromosome 4 from Drosophila melanogaster has several unusual features that distinguish it from the other chromosomes. These include a diffuse appearance in salivary gland polytene chromosomes, an absence of recombination, and the variegated expression of P-element transgenes. As part of a larger project to understand these properties, we are assembling a physical map of this chromosome. Here we report the sequence of two cosmids representing approximately 5% of the polytenized region. Both cosmid clones contain numerous repeated DNA sequences, as identified by cross hybridization with labeled genomic DNA, BLAST searches, and dot matrix analysis, which are positioned between and within the transcribed sequences. The repetitive sequences include three copies of the mobile element Hoppel, one copy of the mobile element HB, and 18 DINE repeats. DINE is a novel, short repeated sequence dispersed throughout both cosmid sequences. One cosmid includes the previously described cubitus interruptus (ci) gene and two new genes: that a gene with a predicted amino acid sequence similar to ribosomal protein S3a which is consistent with the Minute(4)101 locus thought to be in the region, and a novel member of the protein family that includes plexin and met-hepatocyte growth factor receptor. The other cosmid contains only the two short 5'-most exons from the zinc-finger-homolog-2 (zfh-2) gene. This is the first extensive sequence analysis of noncoding DNA from chromosome 4. The distribution of the various repeats suggests its organization is similar to the beta-heterochromatic regions near the base of the major chromosome arms. Such a pattern may account for the diffuse banding of the polytene chromosome 4 and the variegation of many P-element transgenes on the chromosome.  (+info)

Optical mapping of Plasmodium falciparum chromosome 2. (3/6287)

Detailed restriction maps of microbial genomes are a valuable resource in genome sequencing studies but are toilsome to construct by contig construction of maps derived from cloned DNA. Analysis of genomic DNA enables large stretches of the genome to be mapped and circumvents library construction and associated cloning artifacts. We used pulsed-field gel electrophoresis purified Plasmodium falciparum chromosome 2 DNA as the starting material for optical mapping, a system for making ordered restriction maps from ensembles of individual DNA molecules. DNA molecules were bound to derivatized glass surfaces, cleaved with NheI or BamHI, and imaged by digital fluorescence microscopy. Large pieces of the chromosome containing ordered DNA restriction fragments were mapped. Maps were assembled from 50 molecules producing an average contig depth of 15 molecules and high-resolution restriction maps covering the entire chromosome. Chromosome 2 was found to be 976 kb by optical mapping with NheI, and 946 kb with BamHI, which compares closely to the published size of 947 kb from large-scale sequencing. The maps were used to further verify assemblies from the plasmid library used for sequencing. Maps generated in silico from the sequence data were compared to the optical mapping data, and good correspondence was found. Such high-resolution restriction maps may become an indispensable resource for large-scale genome sequencing projects.  (+info)

Telomeric repeats on small polydisperse circular DNA (spcDNA) and genomic instability. (4/6287)

Small polydisperse circular DNA (spcDNA) is a heterogeneous population of extrachromosomal circular molecules present in a large variety of eukaryotic cells. Elevated amounts of total spcDNA are related to endogenous and induced genomic instability in rodent and human cells. We suggested spcDNA as a novel marker for genomic instability, and speculated that spcDNA might serve as a mutator. In this study, we examine the presence of telomeric sequences on spcDNA. We report for the first time the appearance of telomeric repeats in spcDNA molecules (tel-spcDNA) in rodent and human cells. Restriction enzyme analysis indicates that tel-spcDNA molecules harbor mostly, if not exclusively, telomeric repeats. In rodent cells, tel-spcDNA levels are higher in transformed than in normal cells and are enhanced by treatment with carcinogen. Tel-spcDNA is also detected in some human tumors and cell lines, but not in others. We suggest, that its levels in human cells may be primarily related to the amount of the chromosomal telomeric sequences. Tel-spcDNA may serve as a unique mutator, through specific mechanisms related to the telomeric repeats, which distinguish it from the total heterogeneous spcDNA population. It may affect telomere dynamics and genomic instability by clastogenic events, alterations of telomere size and sequestration of telomeric proteins.  (+info)

Structure and inheritance of some heterozygous Robertsonian translocation in man. (5/6287)

Banding studies in 25 Robertsonian translocations showed that all could be interpreted as stable dicentrics. The mechanism for their stability is likely to be the proximity of their centromeres but centromeric suppression could also have a role. In many of these dicentric translocations, discontinuous centromeric suppression, as indicated by chromatid separation at one of the centromeric regions, was observed in C-banded preparations. A further observation of undefined relation to the first was that the ratio of the two constitutive centromeric heterochromatin (CCH) regions from the component chromosomes of the translocations was variable in the same translocation type, e.g. t(13;14). It is proposed that this ratio may influence the segregation ratio. Abnormal spermatogenesis is suggested as the likely mechanism for the difference in the proportion of aneuploid offspring in the progeny of maternal and paternal heterozygotes. Neither of the t dic(21;21)s could be interpreted as isochromosomes. It is proposed that Robertsonian fusion translocations be defined as stable, dicentric, whole-arm translocations, with both centromeres in a median position and resulting in the loss of a small acentric fragment during this formation. It is suggested that they occur at high frequency between telocentric or, as in man, certain acrocentric chromosomes because of some intrinsic property of those chromosomes not possessed by metacentric chromosomes and mediated by interphase association of centromeres.  (+info)

The RNA-editing enzyme ADAR1 is localized to the nascent ribonucleoprotein matrix on Xenopus lampbrush chromosomes but specifically associates with an atypical loop. (6/6287)

Double-stranded RNA adenosine deaminase (ADAR1, dsRAD, DRADA) converts adenosines to inosines in double-stranded RNAs. Few candidate substrates for ADAR1 editing are known at this point and it is not known how substrate recognition is achieved. In some cases editing sites are defined by basepaired regions formed between intronic and exonic sequences, suggesting that the enzyme might function cotranscriptionally. We have isolated two variants of Xenopus laevis ADAR1 for which no editing substrates are currently known. We demonstrate that both variants of the enzyme are associated with transcriptionally active chromosome loops suggesting that the enzyme acts cotranscriptionally. The widespread distribution of the protein along the entire chromosome indicates that ADAR1 associates with the RNP matrix in a substrate-independent manner. Inhibition of splicing, another cotranscriptional process, does not affect the chromosomal localization of ADAR1. Furthermore, we can show that the enzyme is dramatically enriched on a special RNA-containing loop that seems transcriptionally silent. Detailed analysis of this loop suggests that it might represent a site of ADAR1 storage or a site where active RNA editing is taking place. Finally, mutational analysis of ADAR1 demonstrates that a putative Z-DNA binding domain present in ADAR1 is not required for chromosomal targeting of the protein.  (+info)

Transient gene asymmetry during sporulation and establishment of cell specificity in Bacillus subtilis. (7/6287)

Sporulation in Bacillus subtilis is initiated by an asymmetric division generating two cells of different size and fate. During a short interval, the smaller forespore harbors only 30% of the chromosome until the remaining part is translocated across the septum. We demonstrate that moving the gene for sigmaF, the forespore-specific transcription factor, in the trapped region of the chromosome is sufficient to produce spores in the absence of the essential activators SpoIIAA and SpoIIE. We propose that transient genetic asymmetry is the device that releases SpoIIE phosphatase activity in the forespore and establishes cell specificity.  (+info)

A genome-wide screen for asthma-associated quantitative trait loci in a mouse model of allergic asthma. (8/6287)

Asthma is the most common illness of childhood, affecting one child in seven in the UK. Asthma has a genetic basis, but genetic studies of asthma in humans are confounded by uncontrolled environmental factors, varying penetrance and phenotypic pleiotropy. An animal model of asthma would offer controlled exposure, limited and consistent genetic variation, and unlimited size of sibships. Following immunization and subsequent challenge with ovalbumin, the Biozzi BP2 mouse shows features of asthma, including airway inflammation, eosinophil infiltration and non-specific bronchial responsiveness. In order to identify genetic loci influencing these traits, a cross was made between BP2 and BALB/c mice, and a genome-wide screen carried out in the F2progeny of the F1intercross. Five potentially linked loci were identified, four of which corresponded to human regions of syntenic homology that previously have shown linkage to asthma-associated traits.  (+info)

*Genes, Chromosomes and Cancer

... is a monthly peer-reviewed academic journal. According to the Journal Citation Reports, the ... "Genes, Chromosomes & Cancer". 2014 Journal Citation Reports. Web of Science (Science ed.). Thomson Reuters. 2015. Official ...

*Chromosome

Chromosomes in humans can be divided into two types: autosomes (body chromosome(s)) and allosome (sex chromosome(s)). Certain ... Aneuploidy Chromosome segregation DNA Genetic deletion For information about chromosomes in genetic algorithms, see chromosome ... and two sex chromosomes. This gives 46 chromosomes in total. Other organisms have more than two copies of their chromosome ... in humans two chromosomes fused to form chromosome 2. (See Also: Argument from authority#Inaccurate chromosome number) ...

*Lampbrush chromosome

Lampbrush chromosomes are a special form of chromosome found in the growing oocytes (immature eggs) of most animals, except ... Lampbrush chromosomes of tailed and tailless amphibians, birds and insects are described best of all. Chromosomes transform ... Giant chromosomes in the lampbrush form are useful model for studying chromosome organization, genome function and gene ... Chromosome Research. 10: 177 - 200. Gaginskaya E, Kulikova T, Krasikova A (2009) Avian Lampbrush Chromosomes: a Powerful Tool ...

*Balancer chromosome

Balancer chromosomes are named for the chromosome they serve to stabilize and for the phenotypic or genetic marker the balancer ... Balancer chromosomes were first used by Hermann Muller. In the modern usage of balancer chromosomes, random mutations are first ... However, offspring that only get one copy of one balancer chromosome and one copy of a wild type or mutant chromosome will live ... Balancer chromosomes are special, modified chromosomes used for genetically screening a population of organisms to select for ...

*Ring chromosome

A ring chromosome is an aberrant chromosome whose ends have fused together to form a ring. Ring chromosomes were first ... Ring-chromosome-12-syndrome&title=Ring-chromosome-12-syndrome&search=Disease_Search_Simple "Ring chromosome 12 , Genetic and ... Ring-chromosome-16-syndrome&title=Ring-chromosome-16-syndrome&search=Disease_Search_Simple "Ring chromosome 16 , Genetic and ... Ring-chromosome-19-syndrome&title=Ring-chromosome-19-syndrome&search=Disease_Search_Simple "Ring chromosome 20 , Genetic and ...

*Y chromosome

Males have one Y chromosome and one X chromosome, while females have two X chromosomes. In mammals, the Y chromosome contains a ... The chromosome with this allele became the Y chromosome, while the other member of the pair became the X chromosome. Over time ... Stevens proposed that chromosomes always existed in pairs and that the Y chromosome was the pair of the X chromosome discovered ... Only the tips of the Y and X chromosomes recombine. The tips of the Y chromosome that could recombine with the X chromosome are ...

*Chromosome engineering

In an experiment pertaining to chromosome engineering that was conducted in 2006, it was found that chromosome engineering can ... After much experimenting, it was found that manipulating chromosomes, or chromosome engineering, is an excellent and efficient ... Genetics Chromosome Chromosomal deletion Chromosomal inversion Chromosomal translocation DNA Disease "Chromosome engineering". ... Chromosome engineering is "the controlled generation of chromosomal deletions, inversions, or translocations with defined ...

*Chromosome microdissection

... one chromosome may have a piece of another chromosome inserted within it, creating extra bands. Or, a portion of a chromosome ... Scientists who study chromosomes are known as cytogeneticists. They are able to identify each chromosome based on its unique ... Chromosome microdissection is a technique that physically removes a large section of DNA from a complete chromosome. The ... Chromosome microdissection is a specialized way of isolating these regions by removing the DNA from the band and making that ...

*Chromosome regions

Most important is the distinction between chromosome region p and chromosome region q. These are virtual regions that exist in ... At either end of a chromosome is a telomere, a cap of DNA that protects the rest of the chromosome from damage. The areas of ... The p region is represented in the shorter arm of the chromosome (p is for petit, French for small) while the q region is in ... The centromere divides each chromosome into two regions: the smaller one, which is the p region, and the bigger one, the q ...

*Chromosome territories

... chromosome territories are regions of the nucleus preferentially occupied by particular chromosomes. Interphase chromosomes are ... The concept of chromosome territories was proposed by Carl Rabl in 1885 based on studies of Salamandra maculata. Chromosome ... The chromosome territory concept holds that despite this apparent disorder, chromosomes largely occupy defined regions of the ... "Chromosome Territories: The Arrangement of Chromosomes in the Nucleus". Nature Education. Retrieved 15 August 2015. ...

*Chromosome instability

As chromosome instability refers to the rate that chromosomes or large portions of chromosomes are changed, there should be ... It can occur due to loss of a whole chromosome, gain of a whole chromosome or rearrangement of partial chromosomes known as ... Although chromosome instability has long been proposed to promote tumor progression, recent studies suggest that chromosome ... Structural CIN is different in that rather than whole chromosomes, fragments of chromosomes may be duplicated or deleted. The ...

*B chromosome

B chromosomes are not to be confused with marker chromosomes or additional copies of normal chromosomes as they occur in ... B chromosomes may play a positive role on normal A chromosomes in some circumstances. The B chromosomes suppress homologous ... White M.J.D. (1973). The chromosomes (6th ed.). London: Chapman & Hall. ISBN 0-412-11930-7. B Chromosomes B chromosomes in wood ... Chromosome polymorphisms are very common among fungi. Different isolates of the same species often have a different chromosome ...

*Homologous chromosome

The additional 23rd pair is the sex chromosomes, X and Y. If this pair is made up of an X and Y chromosome, then the pair of ... It reduces the chromosome number in a germ cell by half by first separating the homologous chromosomes in meiosis I and then ... Homologous chromosomes are chromosomes which contain the same genes in the same order along their chromosomal arms. There are ... Therefore, when two chromosomes of the exact structure exist, they are able to pair together to form homologous chromosomes. ...

*X chromosome

He called this chromosome an accessory chromosome and insisted, correctly, that it was a proper chromosome, and theorized, ... which later became X chromosome after it was established that it was indeed a chromosome. The idea that the X chromosome was ... Chromosomes are so named because of their ability to take up staining. Although the X chromosome could be stained just as well ... The X chromosome is one of the two sex-determining chromosomes (allosomes) in many organisms, including mammals (the other is ...

*Dicentric chromosome

A dicentric chromosome is an abnormal chromosome with two centromeres. It is formed through the fusion of two chromosome ... a trisomy of chromosome 18, and Turner syndrome, a loss (or partial loss) of the X chromosome. Pseudodicentric chromosomes ... Most dicentric chromosomes are known to form through chromosomal inversions, which are rotations in regions of a chromosome due ... As these chromosomes are pulled apart, the chromosome bridges break, resulting in the formation of "tailed" nuclei, protrusions ...

*Chromosome segregation

Improper chromosome segregation can result in aneuploid gametes having either too few or too many chromosomes. The second stage ... After the first chromosome segregation in meiosis I is complete, there is further chromosome segregation during the second ... These chromosomes (paired chromatids) then pair with the homologous chromosome (also paired chromatids) present in the same ... Both proper initial segregation of chromosomes in prophase I and the next chromosome segregation during equational division in ...

*Derivative chromosome

A derivative chromosome (der) is a structurally rearranged chromosome generated either by a rearrangement involving two or more ... Derivative chromosomes are designated by the abbreviation der when used to describe a Karyotype. The derivative chromosome must ... chromosomes or by multiple aberrations within a single chromosome (e.g. an inversion and a deletion of the same chromosome, or ... band 6 and the long arm of chromosome 8 at region 2, band 2, and a translocation between the long arm of chromosome 4 at region ...

*Philadelphia chromosome

The Philadelphia chromosome is designated Ph (or Ph') chromosome and designates the shortened chromosome 22. It arises from the ... of chromosome 9 and region (1), band (1), sub-band (2) of the long arm (q) of chromosome 22. Hence the chromosome breakpoints ... creating an elongated chromosome 9 (termed a derivative chromosome, or der 9), and a truncated chromosome 22 (the Philadelphia ... or a variant translocation involving another chromosome or chromosomes as well as the long arm of chromosomes 9 and 22). ...

*Parasitic chromosome

... in contrast to A chromosomes. Parasitic Chromosomes are classified as selfish genetic elements. Parasitic chromosomes, if ... Parasitic Chromosomes are often B chromosomes, such that they are not necessarily present in the majority of the species ... Parasitic chromosomes are ¨selfish¨ chromosomes that propagate throughout cell divisions, even if they have no benefit to the ... An example of a parasitic chromosome is the b24 chromosome in grasshoppers. Werren, J. H.; Beukeboom, L. W. (1993-08-01). " ...

*Satellite chromosome

A satellite chromosome or SAT chromosome has a chromosome segment that is separated from the main body of the chromosome by ... In humans, the chromosomes number 13, 14, 15, 21 and 22 are examples of SAT chromosomes. Rieger, R.; Michaelis, A.; Green, M.M ... The satellite at metaphase appears to be attached to the rest of the body of chromosomes by a thread of chromatin. There are at ... Besides the centromere, one or more secondary constrictions can also be observed in some chromosomes at metaphase. The ...

*Marker chromosome

Chromosome 15 has been observed to contribute to a high number of marker chromosomes, but the reason has not been determined. ... A marker chromosome (mar) is a small fragment of a chromosome which generally cannot be identified without specialized genomic ... Marker chromosomes typically occur in addition to the standard 46 chromosomes, making it a partial trisomy or supernumerary ... Marker chromosomes occur sporadically about 70% of the time, with the remainder being inherited from a parent. About 50% of ...

*Chromosome abnormality

It can be from an atypical number of chromosomes or a structural abnormality in one or more chromosomes. Chromosome mutation ... on chromosome 17. Translocations: A portion of one chromosome is transferred to another chromosome. There are two main types of ... A chromosome anomaly may be detected or confirmed in this manner. Chromosome anomalies usually occur when there is an error in ... When the chromosome's structure is altered, this can take several forms: Deletions: A portion of the chromosome is missing or ...

*Chromosome landing

... without any need for chromosome walking and its associated problems. Chromosome landing, together with the technology that has ... From the abstract of PMID 7716809: The strategy of chromosome walking is based on the assumption that it is difficult and time ... Primer walking Tanksley, Steven D.; Ganal, Martin W.; Martin, Gregory B. (February 1995). "Chromosome landing: a paradigm for ... and/or highly repetitive genomes by minimizing the need for chromosome walking. It is based on the principle that the expected ...

*Polycentric chromosome

The polycentric chromosome is when more than 1 Centromere are present in a chromosome. Polycentric chromosome is produced by ... In some algae polycentric chromosome are found normally. In those organism the chromosome instead of remaining at specific ... This kind of chromosome is also known as Holocentric chromosome.. ... It is specifically deadly for cell because at the time of anaphase the polycentric chromosome fails to move to the two opposite ...

*Chromosome jumping

... or additional jumps can be used to progress further along the chromosome. Shotgun sequencing Chromosome walking Chromosome ... Chromosome jumping allows more rapid movement through the genome compared to other techniques, such as chromosome walking, and ... It is related to several other tools used for the same purpose, including chromosome walking. Chromosome jumping is used to ... Thus, sequences not reachable by chromosome walking can be sequenced. Chromosome walking can be used from the new jump position ...
A method is described for localizing DNA sequences hybridized in situ to Drosophila polytene chromosomes. This procedure utilizes a biotin-labeled analog of TTP that can be incorporated enzymatically into DNA probes by nick-translation. After hybridization in situ, the biotin molecules in the probe serve as antigens which bind affinity-purified rabbit antibiotin antibodies. The site of hybridization is then detected either fluorimetrically, by using fluorescein-labeled goat anti-rabbit IgG, or cytochemically, by using an anti-rabbit IgG antibody conjugated to horseradish peroxidase. When combined with Giemsa staining, the immunoperoxidase detection method provides a permanent record that is suitable for detailed cytogenetic analysis. This immunological approach offers four advantages over conventional autoradiographic procedures for detecting in situ hybrids: (i) the time required to determine the site of hybridization is decreased markedly, (ii) biotin-labeled probes are chemically stable and ...
Here we report a technique of laser chromosome welding that uses a violet pulse laser micro-beam for welding. The technique can integrate any size of a desired chromosome fragment into recipient chromosomes by combining with other techniques of laser chromosome manipulation such as chromosome cutting, moving, and stretching. We demonstrated that our method could perform chromosomal modifications with high precision, speed and ease of use in the absence of restriction enzymes, DNA ligases and DNA polymerases. Unlike the conventional methods such as de novo artificial chromosome synthesis, our method has no limitation on the size of the inserted chromosome fragment. The inserted DNA size can be precisely defined and the processed chromosome can retain its intrinsic structure and integrity. Therefore, our technique provides a high quality alternative approach to directed genetic recombination, and can be used for chromosomal repair, removal of defects and artificial chromosome creation. The ...
Author Summary Proper chromosome segregation is essential during the production of eggs and sperm. Chromosome missegregation during meiosis results in the lethality of the offspring or in children carrying extra copies of a given chromosome (for example, Down syndrome). Recombination results in homologous chromosomes becoming physically interlocked in a manner that is normally sufficient to ensure proper segregation. Chromosomes that fail to undergo recombination require additional mechanisms to ensure their proper segregation. In Drosophila melanogaster oocytes we show that chromosomes that fail to recombine undergo dynamic movements on the meiotic spindle prior to their proper segregation. Although previous studies had shown that non-recombinant chromosomes move to opposite sides of the developing meiotic spindle, we show that these chromosomes can cross the spindle and re-associate with their homologs to attempt reorientation. Additionally, we observed threads connecting separated non-recombinant
In mitosis and meiosis, the structure of eukaryotic chromosomes changes dramatically. In interphase, chromosomes occupy relatively large territories in which individual sister chromatids cannot be distinguished (Bolzer et al., 2005; Cremer et al., 2006). In prophase, the volume that is occupied by chromosomes becomes much smaller, chromosomes can thus be observed as individual elongated structures, and sister chromatids are partially resolved from each other in chromosome arm regions (Swedlow and Hirano, 2003). These morphological changes are believed to facilitate the attachments of chromosomes to the mitotic or meiotic spindle and the separation of chromosomes or sister chromatids in anaphase.. The morphological changes of chromosomes in early mitosis and meiosis are caused at least in part by changes in chromosomal protein composition and in the post-translational modification of chromosomal proteins. In mitotic Xenopus egg extracts, both phosphorylation of the linker histone H1 (Maresca et ...
Duplicating chromosomes once each cell cycle produces sister chromatid pairs which separate accurately at anaphase. polytene chromosomes can also separate prior to metaphase through a spindle-independent mechanism termed Separation-Into-Recent-Sisters (SIRS). Both reduplication responses require the spindle assembly checkpoint protein Mad2. While Mad2 delays anaphase separation of metaphase polytene chromosomes Mad2s control of overall mitotic timing ensures efficient SIRS. Our results pinpoint mechanisms enabling continued proliferation after genome reduplication a finding with implications for cancer progression and prevention. DOI: http://dx.doi.org/10.7554/eLife.15204.001 species of fruit fly Stormo and Fox discovered two distinct ways in AR-231453 which cells respond to extra chromosome duplications. One response occurs in cells that were experimentally engineered to undergo an extra chromosome duplication. These cells delay division so that the chromosome separation machinery can somehow ...
Original text and figures were provided by N. Kurata). Chromosome number of cultivated rice was reported as 2n=24 by Kuwada in 1910. Until 1930 this number was confirmed by the observation of rice chromosomes at meiosis. However, due to the extreme smallness, the morphology and structure of rice chromosomes remained unclear and no karyotype analysis was reported until the1970s. Only some attempts of morphological identification based on the figures at pachytene stage in meiosis were reported in this period.. In 1978, Kurata and Omura (1978) invented a new method of chromosome preparation technique, with which karyotype analysis on rice chromosomes was first conducted and identification of all twelve chromosomes became realized. Furthermore, all extra chromosomes of 12 trisomics series of rice (2n=24+1) were identified with this method by Kurata et al. (1981) and Iwata et al. (1984) so that the relationship between the linkage group based on the genes and the chromosomes on which the genes were ...
Contents D1 Prokaryotic chromosome structure D2 Chromatin Structure The Escherichia. coli chromosome, DNA domains, Supercoling of the genome, DNA-binding proteins D2 Chromatin Structure Chromatin, Histones, Nucleosomes, The role of H1, Linker DNA, The 30 nm fiber, Highter order structure D3 Eukaryotic Chromosomal Structure The mitotic chromosome, The centromere, Telomeres, Interphase chromosome, Heterochromatin, Euchromatin, DNase Ⅰ hypersensitivity, CpG methylation, Histone variants and modification D4 Genome complexity Noncoding DNA, Reasociation Kinetics, Unique sequence DNA, Tandem gene clusters, Dispersed repetitive DNA, Satellite DNA, Genetic polymorphism D5 The flow of genetic information The central dogma, Prokaryotic gene expression, Eukaryotic gene expression
Simply put, chromosomes are the structures that hold our genes. Genes are the individual instructions that tell our bodies how to develop and keep our bodies running healthy. In every cell of our body there are 20,000 to 25,000* genes that are located on 46 chromosomes. These 46 chromosomes occur as 23 pairs. We get one of each pair from our mother in the egg, and one of each pair from our father in the sperm. The first 22 pairs are labeled longest to shortest. The last pair are called the sex chromosomes labeled X or Y. Females have two X chromosomes (XX), and males have an X and a Y chromosome (XY). Therefore everyone should have 46 chromosomes in every cell of their body. If a chromosome or piece of a chromosome is missing or duplicated, there are missing or extra genes respectively. When a person has missing or extra information (genes) problems can develop for that individuals health and development. Each chromosomes has a p and q arm; p (petit) is the short arm and q (next letter in the ...
Everyone has 23 pairs of chromosomes, 22 pairs of autosomes and one pair of sex chromosomes. The science that relates to the study of these chromosomes is referred to as Cytogenetics. Our tests that we offer, analyzes the whole chromosome and identifies any disorders present.. Why do a Cytogenic Test?. There are many disorders that can be diagnosed by examining a persons whole chromosome.. Chromosome abnormalities constitute a major category of medical genetic disorders. In a clinical setting, chromosome abnormalities account for a large proportion of cases involving individuals referred with congenital malformations, developmental delay, mental retardation, or infertility; women with gonadal dysgenesis; spontaneous abortions, and couples with repeated spontaneous miscarriages.. Cytogenetic laboratories provide microscopic studies of human chromosomes in order to diagnose abnormalities in prenatal/postnatal and cancer specimens. The studies involve analyzing chromosomes found in blood, bone ...
Do you look a bit like your brothers and sisters? Do you look a bit like your parents? The similarities are because, unless you were adopted, you and the other members of your family have genetic material in common.. Some characteristics, or traits, result from interactions with the environment, others are determined from the genetic material in your chromosomes. Chromosomes are the keepers of the genetic material in eukaryotic cells. An organism has the same chromosomes for its entire life. The chromosomes are located within each cell nucleus. They provide the directions for how the cell is supposed to function and determine some characteristics about how the individual looks. Each chromosome contains a very complex molecule called DNA. The DNA molecule contains genes, which direct how an organisms body is built and maintained.. Heredity is the passage of DNA from the chromosomes of one generation to the chromosomes of the next. Chromosomes in your body are in pairs. One chromosome of each ...
DNA must allow for various processing events; it is transcribed into RNA to make the stored information available to the cell; it is replicated and identical copies of itself are equally distributed to its daughter cells; it is frequently repaired, when damaged by endogenous or exogenous sources. All these processes, whether concerning condensed or uncondensed, mitotic or meiotic chromosomes, make them highly flexible and dynamic structures, which change their nucleotide composition as well as their morphology and position.. Regions on chromosomes that undergo replication or repair are transported to the respective centers of activity, replication factories and repair centers. Likewise, interphase chromosomes or parts thereof shuttle between internal transcriptionally active nuclear domains and the nuclear periphery, depending on their transcriptional activity in certain developmental stages or tissues. The most dramatic chromosome movements occur during mitosis and meiosis when daughter ...
DNA must allow for various processing events; it is transcribed into RNA to make the stored information available to the cell; it is replicated and identical copies of itself are equally distributed to its daughter cells; it is frequently repaired, when damaged by endogenous or exogenous sources. All these processes, whether concerning condensed or uncondensed, mitotic or meiotic chromosomes, make them highly flexible and dynamic structures, which change their nucleotide composition as well as their morphology and position.. Regions on chromosomes that undergo replication or repair are transported to the respective centers of activity, replication factories and repair centers. Likewise, interphase chromosomes or parts thereof shuttle between internal transcriptionally active nuclear domains and the nuclear periphery, depending on their transcriptional activity in certain developmental stages or tissues. The most dramatic chromosome movements occur during mitosis and meiosis when daughter ...
Author Summary The number of chromosomes in organisms often changes over evolutionary time. To study how the number changes, we compare several related species of yeast that share a common ancestor roughly 150 million years ago and have varying numbers of chromosomes. By inferring ancestral genome structures, we examine the changes in location of centromeres and telomeres, key elements that biologically define chromosomes. Their locations change over time by rearrangements of chromosome segments. By following these rearrangements, we trace an evolutionary path between existing centromeres and telomeres to those in the ancestral genomes, allowing us to identify the specific evolutionary events that caused changes in chromosome number. We show that, in these yeasts, chromosome number has generally decreased over time except for one notable exception: an event in an ancestor of several species where the whole genome was duplicated. Chromosome number reduction occurs by the simultaneous removal of a
Two simple models can be envisaged: either cohesins are needed to activate condensin function or, alternatively, cohesins are required to ensure correct chromosome folding by condensins. These models can be distinguished by following the state of the mitotic chromosomes after a loss of cohesin activity. In the first scenario, the chromosomes remain in an interphase state, and thus would condense upon the readdition of cohesin and the subsequent "activation" of condensin. In contrast, the latter scenario predicts that misfolded chromosomes would result from the inappropriate action of condensin, and these would likely prove refractory to refolding. To test this, we asked whether chromosome condensation is reversible in the cohesin mutant mcd1-1. In contrast to both the brn1-9 and ycg1-2 condensin mutants, the condensation defect in the mcd1-1 strain was not reversible (Fig. 7 B). One trivial explanation is that no new functional Mcd1-1p protein is made after the shift to the permissive ...
The sex of a human baby is determined by the composition of its sex chromosomes (a single distinct pair among humans 23 pairs of chromosomes). Females possess two copies of the same chromosome (referred to as the X chromosome); males have one copy of the X chromosome and one copy of the smaller, hook-shaped Y chromosome.. When fertilization occurs, the new gamete (the initial cell from which a fetus grows) always inherits one of the mothers X chromosomes, and either an X or a Y from the father, depending on which chromosome the fertilizing sperm cell happened to inherit. One could say, then, that the father-or, at least, his sperm-determines the sex of the child. On the other hand, the first sperm to reach the egg isnt necessarily the one that fertilizes it; human eggs are rather choosy about that sort of thing. So, in an indirect way, the maternal parent also has some influence on the sex of the child.. Thanks, infoplease.com. Thanks for NOTHING ...
Left: a metaphase plate. Scale bar =lO pm. Right: a single chromosome from the same metaphase. Scale bar = 1 pm. been possible to combine in situ hybridization with high-quality morphological preservation. As well as providing alternative approaches to chromosome morphology, the methods using cytocentrifuge preparation and isolated chromosomes have the advantage of using little or no fixation prior to the osmium impregnation procedure. They are, therefore, well suited to the study of chromosomal antigens that might be destroyed or extracted by methanol-acetic acid fixation (Fig. Ethidium Bromtde Technique (Originally Described by Ikeuchi [2U. 1. When mamtammg cells for making chromosomes by this method, the cells are kept m a semiconfluent state and only split when the flask is fully confluent (stationary phase). This will give a very crude but reasonably effective means of synchronizing rapidly growing cells. However, the chromosomes are in a more nearly "native" state after this. 2. Seventeen ...
Accumulating evidence converges on the possibility that chromosomes interact with each other to regulate transcription in trans. To systematically explore the epigenetic dimension of such interactions, we devised a strategy termed circular chromosome conformation capture (4C). This approach involves …
Nurse cell chromosomes that fail to disperse are also observed in certain alleles of ovarian tumor (otu) (King et al., 1981; King and Storto, 1988; Heino, 1989; Malceva and Zhimulev, 1993; Heino, 1994; Malceva et al., 1995). otu produces two protein isoforms, Otu98 and Otu104, by alternative splicing of a 126 bp exon. Genetic and molecular analyses reveal distinct requirements for each isoform during oogenesis (Storto and King, 1988; Steinhauer and Kalfayan, 1992; Sass et al., 1995; Tirronen et al., 1995). In particular, a mutant that specifically disrupts the Otu104 product has persistent polytene nurse cell chromosomes, suggesting that the 98 kDa Otu isoform is not capable of mediating wild-type chromosome dispersion (Steinhauer and Kalfayan, 1992). This phenotype was also described for mutants in half pint (hfp; pUf68 - FlyBase). Hfp encodes a polyU-binding factor and plays an important role in the alternative splicing of otu. In hfp mutants, there is a dramatic decrease in the levels of ...
ii) A trait is represented by only one Mendelian factor inside a gamete. A gamete similarly contains a single chromosome out of a pair of homologous chromosomes due to meiosis that occurs before the formation of gametes.. (iii) An organism has a specific number of chromosomes. The somatic cells are generally diploid having chromosomes in pairs called homologous pairs. The two chromosomes of each homologous pair resemble each other in their morphology and genetic content. They are derived from the two parents through their gametes. It also contains two Mendelian factors for each character. The factors come from different parents through their gametes.. (iv) Each chromosome replicates during S-phase. It comes to have two sister chromatids. The two chromatids separate and pass into two daughter nuclei and cells during mitosis. Similarly, each allelic pair replicates, with one pair passing into each daughter cell during mitosis. This maintains the similar genetic composition of all the cells of a ...
Like someone whos moved from a house to an apartment, cells in an early embryo run into space limitations. The embryo remains the same size for its first few divisions, so the cells have to become much smaller, shrinking by as much as 99%. Some components, such as individual mitochondria and clathrin-coated vesicles, seemingly remain the same size as cells miniaturize. But the centrosome, mitotic spindle, and nucleus contract. For more than a century researchers have known that cells in early embryos also compact their chromosomes. To prevent tangling during mitosis, the biggest chromosomes cant exceed half the length of the mitotic spindle (2). However, researchers didnt know which cues cells rely on to determine chromosome size. One research group addressed the question by allowing small nuclei to stew in extracts from large cells for an entire cell cycle (3). The nuclei expanded, suggesting that chromosome size tracks cell size. Another group concluded that chromosome size tracks nuclear ...
The reason why the majority of organisms have an even number of chromosomes is because chromosomes are in pairs. A human, for instance, will have half its chromosomes from the father, and half from its mother. There are exceptions to the rule. For instance, an individual with Down Syndrome will have 47 chromosomes instead of 46, because they have trisomy 21 (three copies of the 21st chromosome, instead of just two). Another exception would be polyploidy , which occurs when organisms have more pairs of chromosomes than a diploid cell does. Below is a picture to help visualize polyploidy. An example of a haploid cell would be a gamete (a sperm cell, for instance), and a diploid cell would be a skin cell of a person with 46 chromosomes.
Translocations of a whole chromosome or a chromosome arm have been reported in both normal and abnormal liveborns. Often the abnormal phenotypes could not be explained by the genetic defects of the specific chromosome findings. Warburton et al. described an autosomal anomaly, tdic(12;14), showing gonadal dysgenesis; Pallister et al. described a patient with multiple congenital anomalies and mental retardation who had a normal karyotype in her fibroblasts. The whole chromosome translocation (6;19) was found in her lymphocytes only. Various genetic explanations have been proposed, including undetected lesions, position effects, mutations at the sites of breakage and union, and aneusomy by recombination. Perhaps the whole chromosome translocation per se were not responsible for the malformations, since they were not necessarily found in cells of the deformed organs, or if they were, the abnomalities were not always explained by aberrations of the specific chromsomes involved in the ...
Human chromosomes consist of DNA (the blueprint of genetic material), specific proteins forming the backbone of the chromosome (called histones), and other chromatin structural and interactive proteins. Chromosomes contain most of the genetic information necessary for growth and differentiation. The nuclei of all normal human cells, with the exception of gametes, contain 46 chromosomes, consisting of 23 pairs (Figure 37-1). Of these, 22 pairs are called autosomes. They are numbered according to their size; chromosome 1 is the largest and chromosome 22 the smallest. In addition, there are two sex chromosomes: two X chromosomes in females and one X and one Y chromosome in males. The two members of a chromosome pair are called homologous chromosomes. One homolog of each chromosome pair is maternal in origin (from the egg); the second is paternal (from the sperm). The egg and sperm each contain 23 chromosomes (haploid cells). During formation of the zygote, they fuse into a cell with 46 chromosomes ...
Chromosomes can undergo several types of changes which fall into two classes. The first type of change involves changes in chromosome number and is referred to as aneuploidy and euploidy. How these type of changes can occur and their subsequent effect on phenotype will be discussed in the next section. The chromosomal changes that we will discuss now alter the linear order of the chromosome and occur because of deletions, duplications, inversions, translocations and insertions of chromosomal DNA.. The analysis of these types of changes to a large part has been performed in genetic stocks of the fruit fly, Drosophila melanogaster. The chromosomes of this species that are of particular interest, are those found in the salivary glands of larvae. These tissues grow not by cell division but by enlargement. During this enlargement the chromosomes also undergo replication. But this replication is different than in other tissues because:. ...
Biotechnology and Biological Sciences Research Council. A new method for visualizing chromosomes is painting a truer picture of their shape, which is rarely like the X-shaped blob of DNA most of us are familiar with.. Scientists at the BBSRC-funded Babraham Institute, working with the University of Cambridge and the Weizmann Institute, have produced beautiful 3D models that more accurately show their complex shape and the way DNA within them folds up.. The X-shape, often used to describe chromosomes, is only a snapshot of their complexity.. Dr Peter Fraser of the Babraham Institute explains: "The image of a chromosome, an X-shaped blob of DNA, is familiar to many but this microscopic portrait of a chromosome actually shows a structure that occurs only transiently in cells - at a point when they are just about to divide.". "The vast majority of cells in an organism have finished dividing and their chromosomes dont look anything like the X-shape. Chromosomes in these cells exist in a very ...
Definition of chromosome arm in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is chromosome arm? Meaning of chromosome arm as a legal term. What does chromosome arm mean in law?
We derive an unbiased information theoretic energy landscape for chromosomes at metaphase using a maximum entropy approach that accurately reproduces the details of the experimentally measured pairwise contact probabilities between genomic loci. Dynamical simulations using this landscape lead to cylindrical, helically twisted structures reflecting liquid crystalline order. These structures are similar to those arising from a generic ideal homogenized chromosome energy landscape. The helical twist can be either right or left handed so chiral symmetry is broken spontaneously. The ideal chromosome landscape when augmented by interactions like those leading to topologically associating domain formation in the interphase chromosome reproduces these behaviors. The phase diagram of this landscape shows that the helical fiber order and the cylindrical shape persist at temperatures above the onset of chiral symmetry breaking, which is limited by the topologically associating domain interaction strength ...
Dear community,. while creating an index for the bovine genome with STAR, the process fails because the chromosome names in the annotation file (Bos_taurus.UMD3.1.87.gtf) are incompatible with the ones in the reference file (UMD3.1_chromosomes.fa) (e.g. for chromosome "10" vs "gnl,UMD3.1,GK000010.2 Chromosome 10 AC_000167.1", both should be "10").. Apparently, the solution is to change the names in the reference file. Could you suggest a tool that does this for me or a "one liner" that can transform the names into the chromosome number?. And also, would this affect downstream processing of my results?. I have searched through other threads and couldnt find a better answer than the one given here: Renaming Entries In A Fasta File But it renames chromosomes names in the reference file based on the order they appear.. Cheers!. ...
Youd be forgiven for thinking that all chromosomes are X-shaped bundles. But new research MRC-funded research has shown that they spend most of their time looking more like a tangled mass of string, as Peter Fraser, a researcher at the Babraham Institute, explains. The image of a chromosome as an X-shaped blob is familiar to many. But perhaps not everyone knows that this microscopic portrait of a chromosome shows a structure that occurs only transiently in cells, at a point when they are just about to divide by undergoing a process called mitosis.. The vast majority of cells in an organism have finished dividing and their chromosomes dont look anything like the familiar X-shape. Even cells that are still in the business of dividing, such as blood and skin cells, spend most of their time in a kind of resting non-mitotic state. But what do chromosomes in these cells look like?. So far it has been impossible to create accurate pictures of these chromosomes - existing techniques can only ...
Humans and great apes differ in chromosome numbers-humans have 46 while apes have 48. The difference is claimed to be due to the "end-to-end fusion" of two small, ape-like chromosomes in a human-ape ancestor that joined in the distant past and formed human chromosome 2. This idea was first proposed by researchers who noticed that humans and chimps share similar chromosomal staining patterns when observed under a microscope.1 However, humans and chimps also have regions of their chromosomes that do not share common staining patterns.. Supposed proof for the alleged fusion came in 1991, when researchers discovered a fusion-like DNA sequence about 800 bases in length on human chromosome 2.2 However, it was unexpectedly small in size and extremely degenerate. More importantly, this new fusion-like sequence wasnt what the researchers were expecting to find since it contained a signature never seen before. All known fusions in living animals are associated with a sequence called satellite DNA ...
Human Male Chromosome Spread Next to Cells. Brightfield Photographic Print by Michael Abbey - at AllPosters.com. Choose from over 500,000 Posters & Art Prints. Value Framing, Fast Delivery, 100% Satisfaction Guarantee.
Yale Cancer Center researchers have found an explanation about how a healthy diet and exercise are key in cancer prevention and management.
Animation of human chromosomes. Chromosomes are structures containing an organisms DNA genetic material, which form during cell division. DNA usually exists as a long strand in the cells nucleus, and it is replicated in this form. During replication, another copy of the DNA is produced. In preparation for mitotic cell division, the DNA condenses into chromosomes, a tightly-packed form of DNA shaped like an X. The X is formed of the two identical copies of the genetic material left after replication. These are linked by a central region called the centromere. During mitosis, the two halves of the chromosome (chromatids) separate at the centromere, and each half is pulled to opposite sides of the cell. This then divides, giving rise to two identical daughter cells. Humans have 23 pairs of chromosomes, half of each pair from the mother and father. This animation has a transparent background for comping purposes. It is also available on a white background (K005 5520) and a black background (K005 5517). -
Glowing Green Blood Degree 3 is a rare human disorder caused by recessive allele - ggb3. the normal allele is GGB3 dominant. the gene for this disease is located on the human chromosome #1p, a large metacentric chromosome. The sex chromosomes in humans are the X and Y. A man who is a carrier for Glowing Green Blood Degree 3, but does not have the disease himself, inherited his ggb1 allele from his mother. Using the Genotype of this man, and only considering chromosomes #1, X, and Y, draw the correct configuration of chromosomes for Metaphase of Mitosis and one possibility for Metaphase of Meiosis 1. Shade in the paternal chromosomes and label the appropriate chromatid with the correct gene symbol for the Glowing Green Blood Degree 3 allele it carries. Be sure to label each allele and each chromosome. Do not show crossing over in this assignment ...
The movement of chromosomes may be regarded in two kinds of relationships according as it involves changes of shape and changes of position. The first are due to movements within the chromosomes, and may be used to infer their internal mechanics. The second are due to movements between chromosomes, and may be used to infer their external mechanic. Many experiments have been devoted to elucidating the principles of the external mechanics, and they have been successful in showing certain essential properties of the cell outside the nucleus, particularly of the spindle and the spindle-determining bodies or centrosomes. But, when applied to the chromosomes, artificial treatment has the drawback that in making one primary change it sets up a series of secondary changes whose importance cannot be accurately assessed; comparison is therefore vitiated. The cytoplasm and, in the resting nucleus, a semi-permeable nuclear membrane separates and protects the chromosomes from external stimuli. Thus ...
Chromosomes are structures within cells that carry DNA, RNA, and proteins. Each chromosome is DNA tightly wound around proteins that support its structure. Chromosomes are not visible in the cell unless the cell is dividing and much of the knowledge concerning chromosomes is learned by observing cells during division. In humans, chromosomes are classified in two ways:
The spatial arrangement of some genetic elements relative to chromosome territories and in parallel with the cell nucleus was investigated in human lymphocytes. The structure of the chromosome territories was studied in chromosomes containing regions ( clusters) of highly expressed genes (HSA 9, 17) and those without such clusters ( HSA 8, 13). In chromosomes containing highly expressed regions, the elements pertaining to these regions were found close to the centre of the nucleus on the inner sides of chromosome territories; those pertaining to regions with low expression were localized close to the nuclear membrane on the opposite sides of the territories. In chromosomes with generally low expression ( HSA 8, 13), the elements investigated were found symmetrically distributed over the territories. Based on the investigations of the chromosome structure, the following conclusions are suggested: (1) Chromosome territories have a non-random internal 3D structure with defined average mutual ...
The Chromosome Theory of Heredity Traits are determined by pairs of genes (alleles) A pair of genes are located on a pair of chromosomes, one gene for each trait on each chromosome of a pair. In meiosis, the chromosomes and therefore the genes, segregate independently - one of each pair to a gamete In fertilization, gametes unite resulting in a fertilized egg that has two genes for each trait carried on pairs of chromosomes.
Description of disease Banding of chromosomes. Treatment Banding of chromosomes. Symptoms and causes Banding of chromosomes Prophylaxis Banding of chromosomes
Ross argues that the chromosomal evidence that humans and the higher apes have a different number of chromosomes is invalid or misunderstood. In the early 1990s, it was discovered that human chromosome two is an end-to-end-fusion of two ape chromosomes. A close examination of chromosome two revealed that, while the other twenty-two chromosomes have one centromere, or central segment, human chromosome two has an extra non-functional centromere. Furthermore, while every chromosome has end segments known as telomeres, human chromosome two has inactive adjacent telomere segments in the middle of the chromosome. It is argued that, sometime in our early past, there was a translocation of two chromosomes to form Chromosome two. Ross argues that such a translocation could not possibly have happened because this would be "catastrophic for the organism" and would result in death ...
When a cell divides, it duplicates its chromosomes to make one set for each of the daughter cells. The membrane around the nucleus, which keeps the chromosomes separate from the rest of the cell, breaks down. The two sets of chromosomes then line up and segregate to opposite sides of the cell, pulled apart by a structure of microtubules called the spindle. A new nuclear envelope forms around each set of chromosomes, and new cell membranes separate the two daughter cells ...
View Notes - Reproduction and Chromosome Transmission from BIO 325 at University of Texas. To prepare human chromosomes for viewing (Figure 3.2a): Somatic cells are obtained from the blood. The cells
1. Ferrets have 40 chromosomes in each heart cell. There are ____ chromosomes in each egg. Answer: 20 2. If a skunk has 25 chromosomes in each gamete, then how many chromosomes are in each sperm cell? Answer: 25 3. Sheep have 27 asked by HELP! on December 14, 2014 ...
View Notes - Exam 4 from BIOL 1201 at LSU. Exam 4 I. II. III. IV. V. VI. How many chromosomes are required to have one copy of each gene? Or how many chromosomes are required to have one
A protocol is described for the preparation of high-quality mitotic plant chromosome spreads by a fast air-dry dropping method suitable ...
Most living cells have a defined number of chromosomes: Human cells, for example, have 23 pairs. As cells divide, they can make errors that lead to a gain or loss of chromosomes, which is usually very harmful.. For the first time, MIT biologists have now identified a mechanism that the immune system uses to eliminate these genetically imbalanced cells from the body. Almost immediately after gaining or losing chromosomes, cells send out signals that recruit immune cells called natural killer cells, which destroy the abnormal cells.. The findings raise the possibility of harnessing this system to kill cancer cells, which nearly always have too many or too few chromosomes.. "If we can re-activate this immune recognition system, that would be a really good way of getting rid of cancer cells," says Angelika Amon, the Kathleen and Curtis Marble Professor in Cancer Research in MITs Department of Biology, a member of the Koch Institute for Integrative Cancer Research, and the senior author of the ...
The nucleus of normal human cells contains our genetic blueprint which is organized into 23 pairs of chromosomes, or a total of 46 chromosomes that each contain between one and two thousand genes. Every time a cell divides, each chromosome is carefully replicated and then distributed such that each of the new cells gets a complete and accurate set of chromosomes. Chromosome instability, or a defect in the movement or distribution of chromosomes during cell division, is a major cause of congenital birth defects and major factor in the development of cancer.. Research in my laboratory focuses on the basic mechanisms of how chromosomes assemble and move during cell division, in both normal cells and cancer cells. We are specifically interested in a system in cells that makes sure that the copies of the 46 chromosomes are distributed equally to each of the dividing cells. This checkpoint system works at a specific phase in cell division when the duplicated chromosomes have moved to the middle of the ...
An automatic chromosome analysis system is provided wherein a suitably prepared slide with chromosome spreads thereon is placed on the stage of an automated microscope. The automated microscope stage
Safeguards for maintaining the integrity of chromosomes during cell growth and division can fail, and a cell may find itself trying to divide into two daughter cells with a loose chromosomal fragment drifting away from a broken chromosome. Researchers at UC Santa Cruz are studying a remarkable mechanism that carries broken chromosomes through the process of cell division so that they can be repaired and function normally in the daughter cells.
Staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes.
Genetics is the study of the patterns of inheritance--how traits and characteristics are passed from parents to their children. Genes are formed from segments of DNA (deoxyribonucleic acid), the molecule that encodes genetic information in the cells. DNA controls the structure, function, and behavior of cells and can create exact copies of itself.. Humans have an estimated 70,000 different genes that contain specific genetic information. These genes are located on chromosomes (stick-like structures in the nucleus of cells). Every cell contains 46 chromosomes grouped in 23 pairs. The gamete (egg or sperm) from each parent only contains one half of each chromosome pair. When the two gametes unite and the egg is fertilized, the single chromosomes from each parent join again to form new pairs. The babys gender is determined by one of the chromosome pairs: females have two X chromosomes and males have one X and one Y chromosome.. ...
Im sorry for the confusion but both the single and double purple lines 1 are chromosomes. This gets extra confusing when we are taking chromosomes through mitosis and meiosis - how many chromosomes are at each stage?. NOTE: We wont go over meiosis and mitosis yet but my advice is that you dont worry so much about compartmentalizing all the information but rather think about what is happening. Cell division and gamete creation is a fluid process so the snapshots of details dont give the best understanding. An analogy would be trying to analyze a runner by the snapshots of footstrike then heel raised = you can get lots of detail but the feeling is gone. So well go after the major concepts and then add any needed details at certain spots.. ...
Causes of Chromosome 15q triplication syndrome including triggers, hidden medical causes of Chromosome 15q triplication syndrome, risk factors, and what causes Chromosome 15q triplication syndrome.
Hello All I have list of genes i want to know which all genes will make one chromosome segments So For example i have gene A , B , C , D i want for example A,B, C forming one stretch of chromosome segment (1p15.1p20) 1p15.1p.20 will make one segment. If i have ramdom gene name i want which genes will fall in one stretch of segments.. ...
Im guessing most people are aware that boy-humans and girl-humans have slightly different chromosomes. One pair, out of the 23 pairs that make up (in almost all cases) our genomes, are known as sex chromosomes; girls get two Xs and boys get an X and a Y. So a Y chromosome makes you a guy?…
DNA.[1] It can be from a typical number of chromosomes or a structural abnormality in one or more chromosomes. Chromosome mutation was formerly used in a strict sense to mean a change in a chromosomal segment, involving more than one ...
TEHRAN - Lets just think about the difference between 47 and 46. Is your answer 1? Youre wrong, because the answer may sometimes be something other than 1. If you consider the difference between a 47-chromosome fetus with Down syndrome and a 46-chromosome fetus, the answer will not be 1; the correct answer will be an extra chromosome + an end.
I recently suffered a miscarriage. Genetic studies were done indicating that an extra chromosome was present on the #22 chromosome. What does this chromosome determine ...
Most genome browsers display DNA linearly, using single-dimensional depictions that are useful to examine certain epigenetic mechanisms such as DNA methylation. However, these representations are insufficient to visualize intra-chromosomal interactions and relationships between distal genome features. Relationships between DNA regions may be difficult to decipher or missed entirely if those regions are distant in one dimension but could be spatially proximal when mapped to three-dimensional space. For example, the visualization of enhancers folding over genes is only fully expressed in three-dimensional space. Thus, to accurately understand DNA behavior during gene expression, a means to model chromosomes is essential. The purpose of this project is to facilitate three-dimensional chromosome modelling. The three-dimensional chromosome model will contain a three-tier model of visualization where each subsequent tier is a greater detailed segment of the preceding tier. At the highest level, the ...
Hirano, M., Anderson, D. E., Erickson, H. P., Hirano, T. (2001) Bimodal activation of SMC ATPase by intra- and inter-molecular interactions. Embo Journal, 20 (12). pp. 3238-3250. ISSN 0261-4189 Hirano, T. (2000) Chromosome cohesion, condensation, and separation. Annual Review of Biochemistry, 69. pp. 115-144. ISSN 0066-4154 Hirano, T. (2004) Chromosome shaping by two condensins. Cell Cycle, 3 (1). pp. 26-8. ISSN 1538-4101 (Print) Hirano, T. (2005) Condensins: organizing and segregating the genome. Curr Biol, 15 (7). R265-75. ISSN 0960-9822 (Print) Hirano, T. (2005) SMC proteins and chromosome mechanics: from bacteria to humans. Philos Trans R Soc Lond B Biol Sci, 360 (1455). pp. 507-14. ISSN 0962-8436 (Print) Hirano, T., Kobayashi, R., Hirano, M. (1997) Condensins, chromosome condensation protein complexes containing XCAP-C, XCAP-E and a Xenopus homolog of the Drosophila Barren protein. Cell, 89 (4). pp. 511-21. ISSN 0092-8674 (Print) ...
Canine chromosomes contains more mathematical germinal cell possibilities than the human chromosome! Amazing! Genetics depend on genes that contain DNA, strung into a chromosome that...
As weve seen in previous posts, cancer is caused by some sort of error in the DNA of the cancer. Human DNA comes in 46 long strings called chromosomes and it sometimes breaks, but luckily the break is usually repaired. However, sometimes the repair process gets it wrong - for example two DNA ends are joined together that arent meant…
Chromosome 18Q- or Distal 18q affects the long arm of the chromosome and means there is a deletion of information on the long arm of the 18th Chromosome.
Define chromosome: any of the rod-shaped or threadlike DNA-containing structures of cellular organisms that are located in… - chromosome in a sentence
A karyotype is simply a picture of a persons chromosomes. In order to get this picture, the chromosomes are isolated, stained, and examined under the microscope. Most often, this is done using the chromosomes in the white blood cells. A picture of the chromosomes is taken through the microscope. Then, the picture of the chromosomes is cut up and rearranged by the chromosomes size. ...
Like a cars front and back bumpers, your cells chromosomes are capped by telomeres that protect this genetic material against deterioration. Still, after enough replications, a chromosomes telomeres break down and once ...
The article on page 133 focuses on the classic paper in which Joe Hin Tijo and Albert Levan, in 1956, answered an ostensibly simple question: How many chromosomes are there in a diploid cell of a human? In fact, the question wasnt simple, because finding and separating all the chromosomes in a human nucleus was difficult. During the first half of this century, biologists universally and adamantly insisted that the diploid number was 48. Tijo and Levan devised an improved technique for separating chromosomes and, in observations of 261 embryonic cells, found that "the chromosome number 46 predominated" and was not exceeded. "We do not wish to generalize our present findings into a statement that the chromosome number of human beings is 2n = 46," they wrote, "but it is hard to avoid the conclusion that this would be the most natural explanation of our data." That memorable understatement, hard to beat as an example of sober science writing, seems worthy of considerable discussion in the ...
Structural maintenance of chromosome protein-2 (SMC-2) antibody | | Structural maintenance of chromosomes protein 2 (SMC protein 2), (SMC-2), Chromosome-associated protein E (hCAP-E), XCAP-E homolog, SMC2, CAPE, SMC2L1
Over three decades ago, Birchler (1979) studied the expression of several enzymes in a dosage series of the long arm of chromosome 1 in maize. Some of the gene products that were not encoded on this chromosome arm were negatively correlated in amount with the dosage of the chromosome arm. The range of effect was within the limits of an inverse correlation, and hence, this effect became known as the "inverse effect." Subsequent studies on protein profiles in different dosage series of maize indicated that any one protein could be modulated in this way by several regions of the genome (Birchler and Newton 1981). Any one region would modulate some fraction of the total detectable proteins. In addition to inverse effects, there were also direct correlations of protein levels that operated in trans (i.e. variation of a particular chromosome arm would modulate the expression of a protein encoded elsewhere in the genome). Different chromosome arms produced a few to many effects. Further studies ...
Gene expression compensation of remainder chromosomes in aneuploides. (A) The number of expressed genes (FPKM | 0) along remainder chromosomes. (B,C) Cumulat
Hi there Pink Lady ! Welcome to the Site. Were male factor too. I cant say Ive heard of this specific chromosome test, and as far as I know we didnt have it done. In fact, when I asked about chromosome tests in general they said they didnt do them as a matter of course .. just if there was a specific genetic problem that needed ruling out. I suppose it could depend on dhs sperm results .. You say it isnt a requirement, just advised .. you could ask them why youve been advised of this course of action, as youve heard of others with male factor who havent had this advice .. see what they say ...
An illustration of chromosome, with its parts. (1) Chromatid. One of the two identical parts of the chromosome after S phase. (2) Centromere. The point where the two chromatids touch, and where the microtubules attach. (3) Short arm (4) Long arm ...
The chromosomes The chromosomes are threadlike bodies present in the cells nuclei, and they represent the genetic material of the living organisms , They are
Reference.com says that the function of chromosomes is to carry hereditary information. Chromosomes are located in the nucleus of a cell, and when a cell divides, so do the...
Chromosomes were first seen by C. Nägeli in 1842, and named in 1888 by W. Waldeyer. Walther Flemming studied and documented the behavior of chromosomes during cell division, a process he termed mitosis. We will perform experiments similar to these early scientists. Cell division is especially rapid in the growing root tips of sprouting seeds.…
If you are curious about tiny structures present within the cell, you have to check amazing facts about chromosomes. Chromosomes are a thread like structures
Researchers Create Artificial Eukaryotic Chromosome Researchers led by Dr Jef Boeke of NYU Langone Medical Centers Institute for Systems Genetics have
Answer (1 of 2): Every cell in your body has 23 pair chromosomes (46 total chromosomes). Meiosis is the process where your cells split in two and each has one chromosome from the original pared chromosomes. This cell ends up being (for males) sperm and eggs for females. In sexual reproduction, only one of the many sperm enters the egg of the woman and the chromosomes from the sperm mix with the chromosomes in the egg. In other words, you get half from your mom and half from your dad.
... : Genes, Leukemias, Solid Tumors, and Cancer-Prone Diseases located on Chromosome reviewed and published in the Atlas of Genetics and Cytogenetics in Oncology and Haematology
... : Genes, Leukemias, Solid Tumors, and Cancer-Prone Diseases located on Chromosome 1 reviewed and published in the Atlas of Genetics and Cytogenetics in Oncology and Haematology
Buy Chromosome XY Buildbox Template With Admob by Hive-Codes on CodeCanyon. Chromosome XY is the most vibrant addictive brain challenging game! This game will let you think ahead before you mak...
Lone chromosomes stranded outside the nucleus where their fellow chromosomes reside are thought to be the Robinson Crusoes of the intracellular world.
ThinkGenetic is pleased to announce the advocacy partnership with Chromosome 22 Central, Inc., also known as C22C. Chromosome 22 Central is a parent powered support organization founded in 1997 to… CONTINUE ...
This journal offers high quality papers on all aspects of chromosome and nuclear biology. Coverage emphasizes accounts of experimental studies of chromosome ...
Be Unique. Shop chromosome onesies created by independent artists from around the globe. We print the highest quality chromosome onesies on the internet.
If you have a question about this talk, please contact Dr Ireena Dutta.. Hutchison/MRC Research Centre Seminar. Abstract not available. This talk is part of the Cambridge Oncology Seminar Series series.. ...
These results strongly indicate that the double-Tc/KO mice can be used to obtain antigen-specific hu-mAbs with various isotypes exhibiting desired effector functions. Successful expression of all four hγ subclasses represents an advantage of using hCF vectors to bypass cloning steps because some sequences within the constant region of human IgH locus was found to be unclonable by conventional cloning systems (6). V gene complexity is supposed to be essential for restoration of normal humoral immune response (5), which is important for the production of high affinity hu-mAbs against variety of antigens. Therefore, high affinities of the resultant hu-mAbs suggest that the authentic repertoire of fully human Igs was reconstituted in the double-Tc/KO mice. Although more detailed structural analysis of hCFs may be required to determine whether human Ig loci contained in the double-Tc/KO mice are completely intact, the data presented here and in our previous report (7) suggest that they include ...
A chromosome is a structure of DNA that carries the genetic makeup in the nucleus of the cell. Chromosomes contain giant chain molecules of DNA, coiled and folded as aggregates with specific proteins. Chromosomes ensure that during cell division the hereditary information is evenly distributed to the daughter cells. Normal human body cells have 46 chromosomes. Cancer cells can have a different number and/or structure of chromosomes.. ...
Researchers from Trinity College Dublin have uncovered the evolutionary mechanisms that have caused increases or decreases in the numbers of chromosomes in a group of yeast species during the last 100-150 million years. The ...
Base-Sequence, Chromosome-Mapping, Chromosomes, Comparative-Study, Crosses-Genetic, Cytogenetics, Human, Mice: ge, Mice-Inbred-Strains: ge, Molecular-Sequence-Data, Recombination-Genetic, SUPPORT-NON-U-S-GOVT, SUPPORT-U-S-GOVT-P-H-S. ...
By studying processes that occur at the ends of chromosomes, a team of Heidelberg researchers has unravelled an important mechanism towards a better understanding of cellular aging. The scientists focused on the length of ...
Circular diagram of mutations found in MPN. Chromosomes are illustrated in the outer perimeter. Grey dots show the cancer exome regions of the NimbleGen pan
Study Flashcards On DNA and Chromosomes at Cram.com. Quickly memorize the terms, phrases and much more. Cram.com makes it easy to get the grade you want!
PHYS.ORG Genome folding now has a playbook. A new step-by-step account spells out in minute-time resolution how cells rapidly pack long tangles of chromosomes into the tiny, tightly wound bundles needed for cell division. Cells reel chromosomes into loops, and then... Genome folding now has a playbook. A new step-by-step account spells out in minute-time resolution how cells rapidly pack long tangles of chromosomes into the tiny, tightly wound bundles needed for cell division. Cells reel chromosomes into loops, and then... 2 days ...
genetic material that is out of its normal place, as when deoxyribonucleic acid (DNA) from one chromosome breaks off and gets attached to a different chromosome. See also |b>chromosome|/b>, |b>deoxyribonucleic acid|/b>, |b>mutation|/b>.
PHYS.ORG Genome folding now has a playbook. A new step-by-step account spells out in minute-time resolution how cells rapidly pack long tangles of chromosomes into the tiny, tightly wound bundles needed for cell division. Cells reel chromosomes into loops, and then... Genome folding now has a playbook. A new step-by-step account spells out in minute-time resolution how cells rapidly pack long tangles of chromosomes into the tiny, tightly wound bundles needed for cell division. Cells reel chromosomes into loops, and then... 2 days ...
White, B J.; Tjio, J; Water, L C.; and Crandall, C, "Studies of mice with a balanced complement of 36 chromosomes derived from f1 hybrids of t1wh and t1ald translocation homozygotes." (1972). Subject Strain Bibliography 1972. 2777 ...
Compare Anti-X chromosome controlling element Antibody Products from leading suppliers on Biocompare. View specifications, prices, citations, reviews, and more.
I missed some step in prep of plasmid. So there remained chromosome as well with plasmid. Can I separate thm not by CsCl gradient centrifugation? Point me hit & run methods. Good time today ...
In terms of the human genome, the chromosome 7 pair represents more than 5 percent of all DNA and is estimated to contain up to 1,000 genes that are responsible for the production of proteins with...
TY - JOUR. T1 - Interphase chromosome profiling a method for conventional banded chromosome analysis using interphase nuclei. AU - Babu, Ramesh. AU - Van Dyke, Daniel L.. AU - Dev, Vaithilingam G.. AU - Koduru, Prasad. AU - Rao, Nagesh. AU - Mitter, Navnit S.. AU - Liu, Mingya. AU - Fuentes, Ernesto. AU - Fuentes, Sarah. AU - Papa, Stephen. PY - 2018/2/1. Y1 - 2018/2/1. N2 - Context.-Chromosome analysis on bone marrow or peripheral blood samples fails in a small proportion of attempts. A method that is more reliable, with similar or better resolution, would be a welcome addition to the armamentarium of the cytogenetics laboratory. Objective.-To develop a method similar to banded metaphase chromosome analysis that relies only on interphase nuclei. Design.-To label multiple targets in an equidistant fashion along the entire length of each chromosome, including landmark subtelomere and centromere regions. Each label so generated by using cloned bacterial artificial chromosome probes is molecularly ...
Balancer chromosomes are multiply inverted chromosomes that suppress meiotic crossing over and prevent the recovery of crossover products. Balancers are commonly used in Drosophila melanogaster to maintain deleterious alleles and in stock construction. They exist for all three major chromosomes, yet the molecular location of the breakpoints and the exact nature of many of the mutations carried by the second and third chromosome balancers has not been available. Here, we precisely locate eight of 10 of the breakpoints on the third chromosome balancer TM3, six of eight on TM6, and nine of 11 breakpoints on TM6B. We find that one of the inversion breakpoints on TM3 bisects the highly conserved tumor suppressor gene p53-a finding that may have important consequences for a wide range of studies in Drosophila. We also identify evidence of single and double crossovers between several TM3 and TM6B balancers and their normal-sequence homologs that have created genetic diversity among these chromosomes. ...
Meiosis is a key cellular process of sexual reproduction involving the pairing of homologous sequences. In many species however, meiosis can also involve the segregation of supernumerary chromosomes, which can lack a homolog. How these unpaired chromosomes undergo meiosis is largely unknown. In this study we investigated chromosome segregation during meiosis in the haploid fungus Zymoseptoria tritici that possesses a large complement of supernumerary chromosomes. We used isogenic whole chromosome deletion strains to compare meiotic transmission of chromosomes when paired and unpaired. Unpaired chromosomes inherited from the male parent as well as paired supernumerary chromosomes in general showed Mendelian inheritance. In contrast, unpaired chromosomes inherited from the female parent showed non-Mendelian inheritance but were amplified and transmitted to all meiotic products. We concluded that the supernumerary chromosomes of Z. tritici show a meiotic drive and propose an additional feedback ...
Errors in chromosome segregation in mammalian oocytes lead to aneuploid eggs that are developmentally compromised. In mitotic cells, mitotic centromere associated kinesin (MCAK; KIF2C) prevents chromosome segregation errors by detaching incorrect microtubule-kinetochore interactions. Here, we examine whether MCAK is involved in spindle function in mouse oocyte meiosis I, and whether MCAK is necessary to prevent chromosome segregation errors. We find that MCAK is recruited to centromeres, kinetochores and chromosome arms in mid-meiosis I, and that MCAK depletion, or inhibition using a dominant-negative construct, causes chromosome misalignment. However, the majority of oocytes complete meiosis I and the resulting eggs retain the correct number of chromosomes. Moreover, MCAK-depleted oocytes can recover from mono-orientation of homologous kinetochores in mid-meiosis I to segregate chromosomes correctly. Thus, MCAK contributes to chromosome alignment in meiosis I, but is not necessary for ...
Silene latifolia has heteromorphic sex chromosomes, the X and Y chromosomes. The Y chromosome, which is thought to carry the male determining gene, was isolated by UV laser microdissection and amplified by degenerate oligonucleotide-primed PCR. In situ chromosome suppression of the amplified Y chromosome DNA in the presence of female genomic DNA as a competitor showed that the microdissected Y chromosome DNA did not specifically hybridize to the Y chromosome, but hybridized to all chromosomes. This result suggests that the Y chromosome does not contain Y chromosome-enriched repetitive sequences. A repetitive sequence in the microdissected Y chromosome, RMY1, was isolated while screening repetitive sequences in the amplified Y chromosome. Part of the nucleotide sequence shared a similarity to that of X-43.1, which was isolated from microdissected X chromosomes. Since fluorescence in situ hybridization analysis with RMY1 demonstrated that RMY1 was localized at the ends of the chromosome, RMY1 may ...
B chromosomes have a functional effect on sex determination in a species of cichlid fishes from Lake Victoria [...] The researchers found sex-ratio distortions caused by B chromosomes in the breeding line of the cichlids, as well as several protein-coding genes in the B chromosomes. The resultant ratio was female biased, suggesting a role for B chromosomes in female sex determination. [...] In the present study, the researchers performed an extensive analysis of B chromosomes in cichlid fishes from Lake Victoria to investigate their effect on cichlid evolution. Karyotype analysis of Lake Victoria cichlids suggested that, in one species, Lithochromis rubripinnis, there are female-specific B chromosomes. Crossbreeding experiments suggested that an effector of female sex determination in this species was the B chromosome. Furthermore, analyses of large-scale sequences of B chromosomes in Lake Victoria cichlids revealed multiple protein-coding genes in B chromosomes. The sex determination gene was ...
At the onset of mitosis, cells need to break down their nuclear envelope, form a bipolar spindle and attach the chromosomes to microtubules via kinetochores. Previous studies have shown that spindle bipolarization can occur either before or after nuclear envelope breakdown. In the latter case, early kinetochore-microtubule attachments generate pushing forces that accelerate centrosome separation. However, until now, the physiological relevance of this prometaphase kinetochore pushing force was unknown. We investigated the depletion phenotype of the kinetochore protein CENP-L, which we find to be essential for the stability of kinetochore microtubules, for a homogenous poleward microtubule flux rate and for the kinetochore pushing force. Loss of this force in prometaphase not only delays centrosome separation by 5-6 minutes, it also causes massive chromosome alignment and segregation defects due to the formation of syntelic and merotelic kinetochore-microtubule attachments. By contrast, CENP-L ...
DOSAGE compensation is an essential, chromosome-wide regulatory process that equalizes expression of most X-linked genes between males (usually XO or XY) and females (usually XX), despite their two-fold difference in X chromosome dose. Flies, worms, and mammals utilize diverse mechanisms of dosage compensation, but all involve global changes in X chromosome structure that ultimately serve to adjust the level of X-linked transcripts in only one sex (Cline and Meyer 1996; Meller 2000; Meyer 2000). These X chromosome changes are mediated by dosage compensation machinery that must recognize and associate specifically with the X chromosome(s) of only the dosage-compensating sex. Although the identity and properties of proteins and noncoding RNAs that execute dosage compensation are known in detail, much less is known about the cis-acting factors that must reside on the X chromosome to recruit the dosage compensation machinery. Important advances in understanding the problem of X chromosome ...
The condensin and chromosomal passenger complexes both have important roles in chromosome condensation in mitosis, and the passenger complex has been shown in many systems to be required for localization or phosphorylation of condensin proteins (Giet and Glover 2001; Morishita et al. 2001; Hagstrom et al. 2002; Kaitna et al. 2002; Lavoie et al. 2004; Lipp et al. 2007). Here we observe distinct meiotic consequences of mutations in dcap-g and incenp. Strikingly, SC disassembly was premature in incenp mutants but delayed in dcap-g mutants, and prometaphase I and metaphase I chromosome configurations were disrupted in both mutants, but in clearly distinguishable ways.. That both the condensin and passenger complexes affect SC disassembly is intriguing because little is known about regulation of this process. BubR1 has recently been shown to be required for SC maintenance (Malmanche et al. 2007), although the mechanism has not yet been established. A suggestion that condensin might be required for SC ...

Chromosome Centromeres Are Inherited Epigenetically - RedorbitChromosome Centromeres Are Inherited Epigenetically - Redorbit

This discovery may help to further the development of artificial human chromosomes, which could be used for gene therapies in ... During cell division, the kinetochore provides a point of attachment for the cell skeleton and enables the chromosomes to move ... The cell skeleton, which distributes the chromosomes to the two daughter cells during cell division, attaches to the ... Scientists would like to develop artificial human chromosomes as an alternative to gene therapy using viruses. "Like their ...
more infohttp://www.redorbit.com/news/science/1112415890/chromosome-centromeres-are-inherited-epigenetically/

Artificial chromosome vector - The General Hospital CorporationArtificial chromosome vector - The General Hospital Corporation

The extra telocentric chromosome has two telomeres: one identical to that present on the full length chromosomes, and a new ... This chromosome undergoes breakage, followed by rearrangement or chromosome loss; these events can be detected by karyotype ... Moreover, since the telocentric chromosome is free to recombine with the full length chromosomes, and the telotrisomic stocks ... After integration of this construct into an A. thaliana chromosome, a resolution reaction generates two chromosome fragments, ...
more infohttp://www.freepatentsonline.com/5270201.html

FARA - Evidence for chromosome fragility at the frataxin locus in Friedreich ataxiaFARA - Evidence for chromosome fragility at the frataxin locus in Friedreich ataxia

This chromosome fragility involves the generation of chromosome/chromatid gaps or breaks, or the high frequency loss of one or ... Evidence for chromosome fragility at the frataxin locus in Friedreich ataxia Details Written by Jen Farmer Category: Scientific ... This research shows that the region of chromosome 9 that contains the FXN locus is intrinsically prone to breakage in vivo even ... Other repeat diseases, like Fragile X Syndrome (FXS) have been shown to have chromosome fragility. This has not been previously ...
more infohttps://curefa.org/scientific-news/evidence-for-chromosome-fragility-at-the-frataxin-locus-in-friedreich-ataxia

What are the treatment recommendations for Philadelphia chromosome-negative acute lymphoblastic leukemia (ALL) in adults 40...What are the treatment recommendations for Philadelphia chromosome-negative acute lymphoblastic leukemia (ALL) in adults 40...

Philadelphia chromosome-negative ALL in the older adult (age ≥40 y): Standard multiagent chemotherapy regimen (eg, CALGB 8811 [ ... Philadelphia chromosome-negative ALL in the older adult (age ≥40 y):. * Standard multiagent chemotherapy regimen (eg, CALGB ... Treatment of Philadelphia chromosome-positive acute lymphocytic leukemia with hyper-CVAD and imatinib mesylate. Blood. 2004 Jun ... First report of phase 2 study of dasatinib with hyper-CVAD for the frontline treatment of patients with Philadelphia chromosome ...
more infohttps://www.medscape.com/answers/2004705-171047/what-are-the-treatment-recommendations-for-philadelphia-chromosomenegative-acute-lymphoblastic-leukemia-all-in-adults-40-years-or-older

SMC protein - WikipediaSMC protein - Wikipedia

Likewise, a pair of SMC2 and SMC4 acts as the core of the condensin complexes implicated in chromosome condensation.[7][8] ... SMC proteins represent a large family of ATPases that participate in many aspects of higher-order chromosome organization and ... Hirano T, Kobayashi R, Hirano M (1997). "Condensins, chromosome condensation complex containing XCAP-C, XCAP-E and a Xenopus ... Chuang PT, Albertson DG, Meyer BJ (1994). "DPY-27:a chromosome condensation protein homolog that regulates C. elegans dosage ...
more infohttps://en.wikipedia.org/wiki/SMC_protein

ChromosomesChromosomes

The sex chromosomes are called X and Y. For a child to be female, she must inherit an X chromosome from each parent ... Humans have 46 chromosomes (23 pairs). Half of a persons chromosomes come from the mother and half from the father. One of the ... Chromosomes are cell structures that carry genetic material (DNA), or genes. They are a part of every cell in the body. ... The sex chromosomes are called X and Y. For a child to be female, she must inherit an X chromosome from each parent (XX). For a ...
more infohttps://www.webmd.com/hw-popup/chromosomes

Chromosomes | Encyclopedia.comChromosomes | Encyclopedia.com

Chromosome A chromosome is a structure that occurs within cells and that contains the cells genetic material. That genetic ... Lilies have 24 chromosomes, earthworms have 36 chromosomes, chimps have 48 chromosomes, and horses have 64 chromosomes. The ... lilies have 24 chromosomes, earthworms have 36 chromosomes, chimps have 48 chromosomes, and horses have 64 chromosomes. ... Chromosome UXL Encyclopedia of Science COPYRIGHT 2002 The Gale Group, Inc.. Chromosome. A chromosome is a structure that occurs ...
more infohttps://www.encyclopedia.com/science-and-technology/biology-and-genetics/genetics-and-genetic-engineering/chromosomes

chromosomeschromosomes

... Adam Noel Harris adhar at stanford.edu.XX Sat Dec 20 19:16:04 EST 1997 *Previous message: chromosomes ... KrAzyKoReA ,krazykorea at aol.com, wrote: :Please help A.S.A.P. : :I need the number of chromosomes the Drosophila melanogaster ... has, the amount of :DNA per cell in base pairs, and the ratio of DNA (in base pairs) to number of :chromosomes. I know the ...
more infohttp://bio.net/bionet/mm/dros/1997-December/003639.html

How Chromosomes Pair UpHow Chromosomes Pair Up

"Chromosome 1 from your dad has to be paired with chromosome 1 from your mom, chromosome 2 from your dad with chromosome 2 from ... And because chromosomes come in pairs - 23 sets in humans - the chromosomes must be properly matched up before they can be ... use the ends of their chromosomes to facilitate the process. "These organisms gather all the chromosome ends against the ... "So even though the study of meiosis began in Drosophila, we really havent had any idea how chromosomes initiate synapsis in ...
more infohttps://www.medicalnewstoday.com/releases/237008.php

metaphase chromosomesmetaphase chromosomes

... dcoleman at molbiol.ox.ac.uk dcoleman at molbiol.ox.ac.uk Wed Mar 10 03:16:47 EST 1993 *Previous message ... Basically I am looking for two procedures: 1. how to break open the cells gently, and 2. how to isolate the chromosomes from ... interested in subjecting metaphase chromosomes to electron microscopy. I understanding how to arrest the cells in metaphase --I ... am working with a borrowed culture of a human lymphocytes-- but am unclear on how to extract and purify the chromosomes. ...
more infohttp://www.bio.net/bionet/mm/methods/1993-March/004698.html

Chromosomes] conferencesChromosomes] conferences

shignak at chromosome.net shignak at chromosome.net Thu Mar 16 20:34:43 EST 2006 *Previous message: [Chromosomes] MCF7 and MDA- ... Previous message: [Chromosomes] MCF7 and MDA-MB-231 polymorphisms * Messages sorted by: [ date ] [ thread ] [ subject ] [ ... 16th International Chromosome Conference (ICC-2007) (25-29 August 2007, RAI Conference Centre, Amsterdam, the Netherlands) * ... Dear Chromosomers, Conference information from plant chromosomes mailing list. 1) http://www.icgs-congress.org/ Second Congress ...
more infohttp://www.bio.net/bionet/mm/biochrom/2006-March/002707.html

ChromosomeChromosome

In my previous article, A Chromosome at a Time with Perl, Part I, I showed you some programming "tricks" that help you avoid ... A Chromosome at a Time with Perl, Part 2. Oct 15, 2003 by ...
more infohttps://www.perl.com/tags/chromosome/

Small ChromosomeSmall Chromosome

... Image: Circular representation of the small and large chromosome vibrio cholerae ... are located on the large chromosome. The small chromosome contains a large percentage of hypothetical genes, more genes that ... The toxin genes, of which there are fifty, reside on the large chromosome. The sequencing data confirm that V. cholerae is a ... The complete genome of Vibrio cholerae El Tor N16961 consists of two circular chromosomes (2,961,146 and 1,072,313 base pair) ...
more infohttps://www.nsf.gov/news/speeches/colwell/rc04_indian/tsld014.htm

Chromosomes.JPEG Image IndexChromosomes.JPEG Image Index

Chromosomes 16-22 & Y. All Chromosomes for Four Hominids. High resolution: Diagrams of the chromosomes from humans and 3 great ... Chromosomes and Phylogeny: Modified and reprinted with permission from Yunis, Jorge, and Om Prakash. The Origin of Man: A ...
more infohttp://www.indiana.edu/~ensiweb/lessons/chr.jpeg.html

chromosome - Wiktionarychromosome - Wiktionary

"chromosome" at OneLook Dictionary Search. French[edit]. Etymology[edit]. 19th century: chromo- +‎ -some, from German Chromosom ... chromosome (plural chromosomes). *(cytology, genetics) A structure in the cell nucleus that contains DNA, histone protein, and ... chromosome in Websters Revised Unabridged Dictionary, G. & C. Merriam, 1913. *chromosome in The Century Dictionary, The ... An illustration of chromosome, with its parts. (1) Chromatid. One of the two identical parts of the chromosome after S phase. ( ...
more infohttps://en.wiktionary.org/wiki/chromosome

Chromosome 16 - WikipediaChromosome 16 - Wikipedia

Chromosome 16 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome ... "Chromosome 16". Genetics Home Reference. Retrieved 2017-05-06.. *. "Chromosome 16". Human Genome Project Information Archive ... "Chromosome 16: Chromosome summary - Homo sapiens". Ensembl Release 88. 2017-03-29. Retrieved 2017-05-19.. ... See also: Category:Genes on human chromosome 16.. The following is a partial list of genes on human chromosome 16. For complete ...
more infohttps://en.wikipedia.org/wiki/Chromosome_16

Who discovered chromosomes? | Yahoo AnswersWho discovered chromosomes? | Yahoo Answers

Best Answer: Visual discovery of chromosomes. Textbooks have often said that chromosomes were first observed in plant cells by ... It was only in1956 when Joe-Hin Tjio and Albert Levan in Lund, Sweden showed that the correct human chromosome number is 46. ... Newly discovered chromosome doesnt correlate with fossils so much for Origin-of-Species being Non-Genesis? ...
more infohttps://answers.yahoo.com/question/index?qid=20080714073616AAtSK1c

Sex ChromosomesSex Chromosomes

... the sex chromosomes. All sex chromosomes were derived from pairs of ordinary chromosomes (autosomes). In some instances, the ... a) A male‐dominant gene is present on the Y chromosome. (b) A female‐dominant gene is present on the W chromosome. (c) The ... Bachtrog D (2013) Y‐chromosome evolution: emerging insights into processes of Y‐chromosome degeneration. Nature Reviews ... In many organisms, sex is determined by the presence of specific chromosomes - the sex chromosomes. ...
more infohttp://www.els.net/WileyCDA/ElsArticle/refId-a0005791.html

Homologous chromosomes definition | Drugs.comHomologous chromosomes definition | Drugs.com

Definition of homologous chromosomes. Provided by Stedmans medical dictionary and Drugs.com. Includes medical terms and ... Definition: members of a single pair of chromosomes.. Further information. Always consult your healthcare provider to ensure ...
more infohttps://www.drugs.com/dict/homologous-chromosomes.html

chromosomes | The Morton Arboretumchromosomes | The Morton Arboretum

URL: http:// www.mortonarb.org/science-conservation-tags/chromosomes Copyright 2018 The Morton Arboretum ...
more infohttp://www.mortonarb.org/science-conservation-tags/chromosomes

Those troublesome, shaky X chromosomes! | ScienceBlogsThose troublesome, shaky X chromosomes! | ScienceBlogs

You can do your own research but it comes down to chromosomes -- the X chromosome is shaky, and boys have two of them. So they ... A tiny flaw in the anti-vaxxers "argument" is that boys have an X and a Y chromosome, whereas girls have two X chromosomes. So ... I have 22 other chromosomes besides my sex chromosomes (Ive actually seen them!), and…theyre all in pairs. Im doomed. ... Even if the X chromosome were in some way "shaky" (whatever that means, I cant find it anywhere in a biology textbook), then ...
more infohttps://scienceblogs.com/pharyngula/2016/01/31/those-troublesome-shaky-x-chromosomes

Hot-Y-Chromosomes | DeviantArtHot-Y-Chromosomes | DeviantArt

Hi Tim - Thank you for choosing one of my photos for Hot-Y-Chromosomes.. Best wishes for the groups success!!! ... This group is about celebrating exceptional art portraying either actual or mythical variations of the Y-Chromosome (maleness). ... This group is about celebrating exceptional art portraying either actual or mythical variations of the Y-Chromosome (maleness). ... This group is about celebrating exceptional art portraying either actual or mythical variations of the Y-Chromosome (maleness). ...
more infohttps://www.deviantart.com/hot-y-chromosomes/?offset=900

Human Chromosomes | Orlando J. Miller | SpringerHuman Chromosomes | Orlando J. Miller | Springer

This is the fourth edition of an acclaimed introductory textbook on the structure and function of human chromosomes. The ... This is the fourth edition of an acclaimed introductory textbook on the structure and function of human chromosomes. The ... up-to-date summary of the normal and abnormal behavior of chromosomes. 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. ...
more infohttps://www.springer.com/gp/book/9780387950310?utm_medium=referral&utm_source=mihe&utm_campaign=3_pier05_ppbuybutton&utm_content=en_09012018

Inactivation of Sex Chromosomes | The BMJInactivation of Sex Chromosomes | The BMJ

Inactivation of Sex Chromosomes. Br Med J 1965; 2 doi: https://doi.org/10.1136/bmj.2.5460.494 (Published 28 August 1965) Cite ...
more infohttps://www.bmj.com/content/2/5460/494.1

Supernumerary chromosomes in filamentous fungi | SpringerLinkSupernumerary chromosomes in filamentous fungi | SpringerLink

... a subset of individuals may have more than the minimal complement of chromosomes. If the extra chromosomes are composed ... Supernumerary chromosomes can carry functional genes and, in at least two fungal species, genes on such chromosomes play ... If the extra chromosomes are composed primarily of DNA not found in all representatives of the species, they are most ... Supernumerary chromosomes that confer an adaptive advantage in certain habitats, such as the ability to cause disease on a ...
more infohttps://link.springer.com/article/10.1007/s002940050342
  • Caption: In 2000, the genomes of the two chromosomes possessed by V. cholerae were sequenced. (nsf.gov)
  • 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)
  • Too often when teaching heredity, teachers do not emphasize that whole chromosomes (linkage groups) are inherited from parents. (accessexcellence.org)
  • In a series of experiments beginning in the mid-1880s, Theodor Boveri gave the definitive demonstration that chromosomes are the vectors of heredity. (wikipedia.org)
  • In his famous textbook The Cell in Development and Heredity, Wilson linked together the independent work of Boveri and Sutton (both around 1902) by naming the chromosome theory of inheritance the Boveri-Sutton chromosome theory (the names are sometimes reversed). (wikipedia.org)
  • Right, the fact that men have two X chromosomes is what reduces their risk of color blindness, hemophilia, and other X-linked diseases. (scienceblogs.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)
  • Coverage emphasizes accounts of experimental studies of chromosome organization, function and behavior. (springer.com)
  • Within a fungal species, a subset of individuals may have more than the minimal complement of chromosomes. (springer.com)
  • Only two triploids had an XYY sex chromosome complement, one of which was mosaic with loss of an autosome and the other was a chimera. (biomedsearch.com)
  • Some model organisms employed in the study of meiosis, such as yeast and the roundworm Caenorhabditis elegans, use the ends of their chromosomes to facilitate the process. (medicalnewstoday.com)
  • These organisms gather all the chromosome ends against the nuclear envelope into one big cluster called a bouquet or into a bunch of smaller clusters called aggregates, and this brings the chromosome ends into proximity with each other," Hawley says. (medicalnewstoday.com)
  • In many organisms, the genetic information required for the differentiation of fertilised eggs into individuals of different sexes is contained on a special pair of chromosomes: the sex chromosomes. (els.net)
  • In many organisms, sex is determined by the presence of specific chromosomes - the sex chromosomes. (els.net)
  • Before this happens, every chromosome is copied once (S phase), and the copy is joined to the original by a centromere, resulting either in an X-shaped structure (pictured to the right) if the centromere is located in the middle of the chromosome or a two-arm structure if the centromere is located near one of the ends. (wikipedia.org)
  • Ford CE, Jones KW, Polani PE, deAlmeida JC and Briggs JH (1959a) A sex‐chromosome anomaly in a case of gonadal dysgennesis (Turner's syndrome). (els.net)
  • In addition to describing the structural and functional characteristics of known supernumerary chromosomes in fungi, this review discusses the relative merits of the terms that have been used to describe them, and establishes experimental criteria for their identification. (springer.com)
  • Meiosis reduces the number of chromosomes carried by an individual's regular cells by half, allocating precisely one copy of each chromosome to each egg or sperm cell and thus ensuring that the proper number of chromosomes is passed from parent to offspring. (medicalnewstoday.com)
  • This group is about celebrating exceptional art portraying either actual or mythical variations of the Y-Chromosome (maleness). (deviantart.com)
  • One sheet represents the chromosomes of your mother's egg and the other sheet represents the chromosomes from your father's sperm. (accessexcellence.org)
  • The egg and sperm cells each contain 23 chromosomes. (encyclopedia.com)
  • Ellegren H (2012) Sex‐chromosome evolution: recent progress and the influence of male and female heterogamety. (els.net)
  • Bachtrog D (2013) Y‐chromosome evolution: emerging insights into processes of Y‐chromosome degeneration. (els.net)
  • It thus becomes possible to distinguish the sex of an embryo by counting the chromosomes of its cells. (dictionary.com)
  • In this highly condensed form chromosomes are easiest to distinguish and study. (wikipedia.org)
  • If the extra chromosomes are composed primarily of DNA not found in all representatives of the species, they are most appropriately referred to as supernumerary chromosomes. (springer.com)
  • Each species of plant or animal has a characteristic number of chromosomes. (dictionary.com)
  • Even if the X chromosome were in some way "shaky" (whatever that means, I can't find it anywhere in a biology textbook), then that would mean that GIRLS are at more risk. (scienceblogs.com)