gene bank

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gene bank

  1. a collection of clones containing all the genes of a particular organism, such as E. coli. The bank can be prepared by isolating the DNA from an organism, digesting it with a RESTRICTION ENZYME and cloning the restriction fragments. It can be maintained for many years, to provide a repository of cloned genetic material.
  2. a collection of many lines of a particular crop plant, seeds or pollen used as a genetic resource by plant breeders; or of sperm, ova, embryos in the case of animals.
  3. a collection of DNA sequences (genetic database) stored at a specific Internet site, such as Genbank ( See also BIOINFORMATICS.


the unit of heredity most simply defined as a specific segment of DNA, usually in the order of 1000 nucleotides, that specifies a single polypeptide. Many phenotypic characteristics are determined by a single gene, while others are multigenic. Genes are specifically located in linear order along the single DNA molecule that makes up each chromosome. All eukaryotic cells contain a diploid (2n) set of chromosomes so that two copies of each gene, one derived from each parent, are present in each cell; the two copies often specify a different phenotype, i.e. the polypeptide will have a somewhat different amino acid composition. These alternative forms of gene, both within and between individuals, are called alleles. Genes determine the physical (structural genes), the biochemical (enzymes), physiological and behavioral characteristics of an animal.
The formation of gametes (sperm, ova) involves a process of meiosis, which allows crossing over between four pairs of chromosomes, two derived from each parent, which means that new forms of a particular chromosome are created. Gamete formation also results in cells (gametes) with a haploid (n) set of chromosomes that in fertilization creates a new individual, which is a recombinant of 2n chromosomes, half derived by way of the ovum from the mother and half via the spermatozoa from the father.
Changes in the nucleotide sequence of a gene, either by substitution of a different nucleotide or by deletion or insertion of other nucleotides, constitute mutations which add to the diversity of animal species by creating different alleles and can be used as a basis for genetic selection of different phenotypes. Some mutations, be they a single base change in a single gene or a major deletion, are lethal.

gene action
the way in which genes exert their effects on tissues or processes, e.g. by being dominant or recessive, or partially so, being absent, being sex-linked, being involved in chromosomal aberrations.
allelic g's
different forms of a particular gene usually situated at the same position (locus) in a pair of chromosomes.
gene amplification
see gene duplication (below).
gene bank
the collection of DNA sequences in a given genome. Called also gene library.
barring gene
responsible for the barred pattern on the feathers of Barred Plymouth Rock birds.
gene box
see box (4).
gene clone
see clone.
gene cluster
a group of related genes derived from a common ancestral gene, located closely together on the same chromosome. Called also multigene family.
complementary g's
two independent pairs of nonallelic genes, neither of which is functional without the other.
gene conversion
a non-reciprocal exchange of DNA elements during meiosis which results in a functional rearrangement of chromosomal DNA.
dhfr gene
dihydrofolate reductase gene; an enzyme required to maintain cellular concentrations of H2 folate for nucleotide biosynthesis, and which has been used as a 'selective marker'; cells lacking the enzyme only survive in media containing thymidine, glycine and purines; mutant cells (dhfr) transfected with DNA that is dhfr′ can be selectively grown in medium lacking these elements.
diversity (D) gene
genes located in diversity (D) segment; contribute to the hypervariable region of immunoglobulins.
dominant gene
one that produces an effect (the phenotype) in the organism regardless of the state of the corresponding allele. Examples of traits determined by dominant genes are short hair in cats and black coat color in dogs.
gene duplication
as a result of non-homologous recombination, a chromosome carries two or more copies of a gene.
gene expression
gene frequency
the proportion of the substances or animals in the group which carry a particular gene.
holandric g's
genes located on the Y chromosome and appearing only in male offspring.
immune response (Ir) g's
genes of the major histocompatibility complex (MHC) that govern the immune response to individual immunogens.
jumping gene
see mobile dna.
gene knockout
replacement of a normal gene with a mutant allele, as in gene knockout mice.
lethal gene
one whose presence brings about the death of the organism or permits survival only under certain conditions.
gene library
see gene bank (above).
gene locus
see locus.
mutant gene
one that has undergone a detectable mutation.
non-protein encoding gene
the final products of some genes are RNA molecules rather than proteins.
overlapping g's
when more than one mRNA is transcribed from the same DNA sequence; the mRNAs may be in the same reading frame but of different size or they may be in different reading frames.
gene pool
total of all genes possessed by all members of the population which are capable of reproducing during their lifetime.
gene probe
see probe (2).
recessive gene
one that produces an effect in the organism only when it is transmitted by both parents, i.e. only when the individual is homozygous.
regulator gene, repressor gene
one that synthesizes repressor, a substance which, through interaction with the operator gene, switches off the activity of the structural genes associated with it in the operon.
reporter gene
one that produces products which can be measured and therefore used as an indicator of whether a DNA construct has successfully been transferred.
sex-linked gene
one that is carried on a sex chromosome, especially an X chromosome.
gene splicing
structural gene
nucleotide sequences coding for proteins.
gene therapy
the insertion of functional genes into cells of the host in order to alter its phenotype, usually used to treat an inherited defect.
gene transcription
gene transfer
tumor suppressor g's
a class of genes that encode proteins that normally suppress cell division that when mutated allow cells to continue unrestricted cell division and may result in a tumor.
References in periodicals archive ?
The GeneBank accession numbers of IBV variants are: IBV/Brazil/SC02 (GQ169247), IBV/Brazil/PR07 (GQ169244), IBV/Brazil/SP02 (GQ169250), Cuba/La Habana/CB6/2009 (HE590762), Cuba/La Habana/CB13/2009 (HE590763), Cuba/La Habana/CB19/2009 (HE590764), AR03BA06 (FJ167386), AR06BA13 (FJ167376), AR06BA14 (FJ167375).
The genebank can help ARS and other researchers around the country to breed better bees now and in the future.
The project will be undertaken by the agriculture department, the 29-year-old Philippine Rice Research Institute, the 55-year-old International Rice Research Institute (IRRI), IRRI's International Rice Genebank, and several non-government organisations, one of which is the Heirloom Rice Project.
2010) mentioned that cytogenetic studies of different Capsicum genebank accessions comprise an important data source for breeders, which allows for better gene pool administration and a more efficient selection of genetic resources.
The AVRDC Genebank is the world's premier collection of tropical and subtropical vegetable genetic resources in the public domain; its seed, knowledge, and information are accessible to all.
Jarvis co-led the Avian Phylogenomics Consortium with Guojie Zhang of the National Genebank at BGI in China and the University of Copenhagen and M.
The fate of germplasm in situ and the efficiency of its collection, preservation, and evaluation in the genebank are all influenced by the interaction of population structure and population sampling techniques.
To give an indication of the breadth of this diversity, the collection of barley, chickpea, fava bean, forages, lentil and wheat at the International Center for Agricultural Research in the Dry Areas (ICARDA) genebank in Syria, with which I was heavily involved in the 1970s and 1980's, conserves a staggering 135,000 varieties from over 110 countries.
Unfortunately, there are none among the more than 124,000 types of rice collected from all over the world and conserved at the IRRI genebank in Los BaAaAaAeA~os.