Any method used for determining the location of and relative distances between genes on a chromosome.

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)

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.

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.

A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.

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.

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.

A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.

The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.

The large, metacentric human chromosomes, called group A in the human chromosome classification. This group consists of chromosome pairs 1, 2, and 3.

A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.

The short, submetacentric human chromosomes, called group E in the human chromosome classification. This group consists of chromosome pairs 16, 17, and 18.

A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.

Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.

A specific pair GROUP C CHROMSOMES of the human chromosome classification.

A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.

A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.

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)

A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.

A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.

A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.

A specific pair of GROUP C CHROMSOMES of the human chromosome classification.

A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.

A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.

Chromosomes in which fragments of exogenous DNA ranging in length up to several hundred kilobase pairs have been cloned into yeast through ligation to vector sequences. These artificial chromosomes are used extensively in molecular biology for the construction of comprehensive genomic libraries of higher organisms.

Mapping of the KARYOTYPE of a cell.

A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.

Actual loss of portion of a chromosome.

A specific pair of GROUP B CHROMOSOMES of the human chromosome classification.

The medium-sized, acrocentric human chromosomes, called group D in the human chromosome classification. This group consists of chromosome pairs 13, 14, and 15.

A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.

The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.

Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.

A technique for visualizing CHROMOSOME ABERRATIONS using fluorescently labeled DNA probes which are hybridized to chromosomal DNA. Multiple fluorochromes may be attached to the probes. Upon hybridization, this produces a multicolored, or painted, effect with a unique color at each site of hybridization. This technique may also be used to identify cross-species homology by labeling probes from one species for hybridization with chromosomes from another species.

The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.

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.

The short, acrocentric human chromosomes, called group G in the human chromosome classification. This group consists of chromosome pairs 21 and 22 and the Y chromosome.

A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.

A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.

The large, submetacentric human chromosomes, called group B in the human chromosome classification. This group consists of chromosome pairs 4 and 5.

Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of MAMMALS.

A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.

One of the two pairs of human chromosomes in the group B class (CHROMOSOMES, HUMAN, 4-5).

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.

A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.

Structures within the nucleus of fungal cells consisting of or containing DNA, which carry genetic information essential to the cell.

Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.

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.

Clinical conditions caused by an abnormal chromosome constitution in which there is extra or missing chromosome material (either a whole chromosome or a chromosome segment). (from Thompson et al., Genetics in Medicine, 5th ed, p429)

The alignment of CHROMOSOMES at homologous sequences.

The short, metacentric human chromosomes, called group F in the human chromosome classification. This group consists of chromosome pairs 19 and 20.

A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.

The human female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in humans.

The human male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans.

A type of chromosomal aberration involving DNA BREAKS. Chromosome breakage can result in CHROMOSOMAL TRANSLOCATION; CHROMOSOME INVERSION; or SEQUENCE DELETION.

The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.

The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.

An aberration in which 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.

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)

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.

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).

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.

Plasmids containing at least one cos (cohesive-end site) of PHAGE LAMBDA. They are used as cloning vehicles.

A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.

A 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.

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.

The mechanisms of eukaryotic CELLS that place or keep the CHROMOSOMES in a particular SUBNUCLEAR SPACE.

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.

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.

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.

Aberrant chromosomes with no ends, i.e., circular.

Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.

A 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.

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).

A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.

Mapping of the linear order of genes on a chromosome with units indicating their distances by using methods other than genetic recombination. These methods include nucleotide sequencing, overlapping deletions in polytene chromosomes, and electron micrography of heteroduplex DNA. (From King & Stansfield, A Dictionary of Genetics, 5th ed)

A 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).

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.

A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)

The 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.

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).

The possession of a third chromosome of any one type in an otherwise diploid cell.

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)

The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.

The total relative probability, expressed on a logarithmic scale, that a linkage relationship exists among selected loci. Lod is an acronym for "logarithmic odds."

A 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.

Susceptibility of chromosomes to breakage leading to translocation; CHROMOSOME INVERSION; SEQUENCE DELETION; or other CHROMOSOME BREAKAGE related aberrations.

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.

Overlapping of cloned or sequenced DNA to construct a continuous region of a gene, chromosome or genome.

Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.

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.

A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.

Established cell cultures that have the potential to propagate indefinitely.

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.

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.

A terminal section of a chromosome which has a specialized structure and which is involved in chromosomal replication and stability. Its length is believed to be a few hundred base pairs.

The 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.

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.

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.

Structures within the CELL NUCLEUS of insect cells containing DNA.

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.

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.)

The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.

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.

Structures which are contained in or part of CHROMOSOMES.

A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.

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.

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.

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)

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

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.

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.

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.

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.

Genes bearing close resemblance to known genes at different loci, but rendered non-functional by additions or deletions in structure that prevent normal transcription or translation. When lacking introns and containing a poly-A segment near the downstream end (as a result of reverse copying from processed nuclear RNA into double-stranded DNA), they are called processed genes.

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.

Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.

PHENOTHIAZINES with an amino group at the 3-position that are green crystals or powder. They are used as biological stains.

A form of GENE LIBRARY containing the complete DNA sequences present in the genome of a given organism. It contrasts with a cDNA library which contains only sequences utilized in protein coding (lacking introns).

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.

The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.

The failure of homologous CHROMOSOMES or CHROMATIDS to segregate during MITOSIS or MEIOSIS with the result that one daughter cell has both of a pair of parental chromosomes or chromatids and the other has none.

The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.

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.

Genetic loci associated with a QUANTITATIVE TRAIT.

The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.

'Abnormalities, Multiple' is a broad term referring to the presence of two or more structural or functional anomalies in an individual, which may be genetic or environmental in origin, and can affect various systems and organs of the body.

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.

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.

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.

An aberration in which an extra chromosome or a chromosomal segment is made.

An increased tendency to acquire CHROMOSOME ABERRATIONS when various processes involved in chromosome replication, repair, or segregation are dysfunctional.

Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.

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.

Chromosome regions that are loosely packaged and more accessible to RNA polymerases than HETEROCHROMATIN. These regions also stain differentially in CHROMOSOME BANDING preparations.

Genotypic differences observed among individuals in a population.

RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.

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.

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.

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.

This single species of Gorilla, which is a member of the HOMINIDAE family, is the largest and most powerful of the PRIMATES. It is distributed in isolated scattered populations throughout forests of equatorial Africa.

An autosomal dominant disorder caused by deletion of the proximal long arm of the paternal chromosome 15 (15q11-q13) or by inheritance of both of the pair of chromosomes 15 from the mother (UNIPARENTAL DISOMY) which are imprinted (GENETIC IMPRINTING) and hence silenced. Clinical manifestations include MENTAL RETARDATION; MUSCULAR HYPOTONIA; HYPERPHAGIA; OBESITY; short stature; HYPOGONADISM; STRABISMUS; and HYPERSOMNOLENCE. (Menkes, Textbook of Child Neurology, 5th ed, p229)

An individual having different alleles at one or more loci regarding a specific character.

DNA constructs that are derived from the DNA of BACTERIOPHAGE P1. They can carry large amounts (about 100-300 kilobases) of other sequence for a variety of bioengineering purposes.

The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.

A species of orangutan, family HOMINIDAE, found in the forests on the island of Borneo.

The condition in which one chromosome of a pair is missing. In a normally diploid cell it is represented symbolically as 2N-1.

Large multiprotein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase in the cell cycle.

The relationships of groups of organisms as reflected by their genetic makeup.

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.

The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.

The presence of two or more genetic loci on the same chromosome. Extensions of this original definition refer to the similarity in content and organization between chromosomes, of different species for example.

Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.

A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.

Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.

The process by which a DNA molecule is duplicated.

A subdiscipline of genetics which deals with the cytological and molecular analysis of the CHROMOSOMES, and location of the GENES on chromosomes, and the movements of chromosomes during the CELL CYCLE.

The 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).

A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research.

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.

Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.

The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.

The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.

Genes that influence the PHENOTYPE only in the homozygous state.

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.

An individual in which both alleles at a given locus are identical.

A characteristic symptom complex.

A species of fruit fly much used in genetics because of the large size of its chromosomes.

Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.

A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.

The sequential location of genes on a chromosome.

Fusion of somatic cells in vitro or in vivo, which results in somatic cell hybridization.

Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.

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.

A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.

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.

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)

Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.

A species of temperate bacteriophage in the genus P1-like viruses, family MYOVIRIDAE, which infects E. coli. It is the largest of the COLIPHAGES and consists of double-stranded DNA, terminally redundant, and circularly permuted.

The common chimpanzee, a species of the genus Pan, family HOMINIDAE. It lives in Africa, primarily in the tropical rainforests. There are a number of recognized subspecies.

The locations in specific DNA sequences where CHROMOSOME BREAKS have occurred.

A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.

Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.

Nonrandom association of linked genes. This is the tendency of the alleles of two separate but already linked loci to be found together more frequently than would be expected by chance alone.

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.

Insertion of viral DNA into host-cell DNA. This includes integration of phage DNA into bacterial DNA; (LYSOGENY); to form a PROPHAGE or integration of retroviral DNA into cellular DNA to form a PROVIRUS.

DNA present in neoplastic tissue.

A family of the order Rodentia containing 250 genera including the two genera Mus (MICE) and Rattus (RATS), from which the laboratory inbred strains are developed. The fifteen subfamilies are SIGMODONTINAE (New World mice and rats), CRICETINAE, Spalacinae, Myospalacinae, Lophiomyinae, ARVICOLINAE, Platacanthomyinae, Nesomyinae, Otomyinae, Rhizomyinae, GERBILLINAE, Dendromurinae, Cricetomyinae, MURINAE (Old World mice and rats), and Hydromyinae.

White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.

The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.

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)

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.

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.

The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.

The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.

Animals that are produced through selective breeding to eliminate genetic background differences except for a single or few specific loci. They are used to investigate the contribution of genetic background differences to PHENOTYPE.

'Poisonous fishes' are aquatic organisms belonging to the Phylum Chordata and Class Pisces, that contain toxic substances either in their tissues or secretions, which can cause harmful or lethal effects when ingested, touched, or coming into contact with their released toxins.

An enzyme that catalyzes the conversion of alpha D-glucose 1-phosphate to alpha D-glucose 6-phosphate. EC 5.4.2.2.

Family of the suborder HAPLORHINI (Anthropoidea) comprising bipedal primate MAMMALS. It includes modern man (HOMO SAPIENS) and the great apes: gorillas (GORILLA GORILLA), chimpanzees (PAN PANISCUS and PAN TROGLODYTES), and orangutans (PONGO PYGMAEUS).

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.

A genus of the family HYLOBATIDAE consisting of six species. The members of this genus inhabit rain forests in southeast Asia. They are arboreal and differ from other anthropoids in the great length of their arms and very slender bodies and limbs. Their major means of locomotion is by swinging from branch to branch by their arms. Hylobates means dweller in the trees. Some authors refer to Symphalangus and Nomascus as Hylobates. The six genera include: H. concolor (crested or black gibbon), H. hoolock (Hoolock gibbon), H. klossii (Kloss's gibbon; dwarf siamang), H. lar (common gibbon), H. pileatus (pileated gibbon), and H. syndactylus (siamang). H. lar is also known as H. agilis (lar gibbon), H. moloch (agile gibbon), and H. muelleri (silvery gibbon).