recessive gene


Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
Related to recessive gene: Recessive allele

gene

 [jēn]
one of the biologic units of heredity, self-reproducing, and located at a definite position (locus) on a particular chromosome. Genes make up segments of the complex deoxyribonucleic acid (DNA) molecule that controls cellular reproduction and function. There are thousands of genes in the chromosomes of each cell nucleus; they play an important role in heredity because they control the individual physical, biochemical, and physiologic traits inherited by offspring from their parents. Through the genetic code of DNA they also control the day-to-day functions and reproduction of all cells in the body. For example, the genes control the synthesis of structural proteins and also the enzymes that regulate various chemical reactions that take place in a cell.

The gene is capable of replication. When a cell multiplies by mitosis each daughter cell carries a set of genes that is an exact replica of that of the parent cell. This characteristic of replication explains how genes can carry hereditary traits through successive generations without change.
allelic gene allele.
complementary g's two independent pairs of nonallelic genes, neither of which will produce its effect in the absence of the other.
DCC gene (deleted in colorectal carcinoma) a gene normally expressed in the mucosa of the colon but reduced or absent in a small proportion of patients with colorectal cancer.
dominant gene one that produces an effect (the phenotype) in the organism regardless of the state of the corresponding allele. An example of a trait determined by a dominant gene is brown eye color. See also heredity.
histocompatibility gene one that determines the specificity of tissue antigenicity (hla antigens) and thus the compatibility of donor and recipient in tissue transplantation and blood transfusion.
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 that govern the immune response to individual immunogens.
immune suppressor (Is) g's genes that govern the formation of suppressor T lymphocytes.
immunoglobulin g's the genes coding for immunoglobulin heavy and light chains, which are organized in three loci coding for κ light chains, λ light chains, and heavy chains.
K-ras gene a type of oncogene.
lethal gene one whose presence brings about the death of the organism or permits survival only under certain conditions.
major gene a gene whose effect on the phenotype is always evident, regardless of how this effect is modified by other genes.
mutant gene one that has undergone a detectable mutation.
operator gene one serving as a starting point for reading the genetic code, and which, through interaction with a repressor, controls the activity of structural genes associated with it in the operon.
gene pool all of the genes possessed by all of the members of a population that will reproduce.
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. See also heredity.
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.
sex-linked gene a gene carried on a sex chromosome (X or Y); only X linkage has clinical significance. See X-linked gene.
structural gene one that forms templates for messenger RNA and is thereby responsible for the amino acid sequence of specific polypeptides.
tumor suppressor gene a gene whose function is to limit cell proliferation and loss of whose function leads to cell transformation and tumor growth; called also antioncogene.
X-linked gene a gene carried on the X chromosome; the corresponding trait, whether dominant or recessive, is always expressed in males, who have only one X chromosome. the term “X-linked” is sometimes used synonymously with “sex-linked,” since no genetic disorders have as yet been associated with genes on the Y chromosome.

recessive allele

or

recessive gene

an ALLELE that only shows its effect in the PHENOTYPE when present in a HOMOZYGOTE. When paired with a dominant allele the effect of the recessive allele is hidden. see RECESSIVE CHARACTER.

Recessive gene

A type of gene that is not expressed as a trait unless inherited by both parents.

recessive gene

a gene which expresses itself in the homozygous state, but not in the presence of the dominant allele.
References in periodicals archive ?
The study called on marriage officials to make sure prospective couples abide by the law and are pre-screened for the presence of shared recessive genes, as well as HIV and hepatitis B and C.
These anecdotal observations strongly suggest the presence of a recessive gene or genes," said Wang.
But, researchers also determined that he carried the recessive gene which blocks this ability.
It has a unique recessive gene which produces white hair instead of black.
Both parents must carry the recessive gene that triggers it, and even then only one in four offspring will have XP.
RECESSIVE GENE Recessive genes are "weak" and are always dominated by strong, dominant genes unless two for a particular trait get together because they're donated by each parent.
White tigers are a colour morph of the tiger, caused by the recessive gene 'chinchilla albinistic'.
The albino hedgehogs, which are one in 100,000, are born with the recessive gene that means they have no melanin pigment in their skin, eyes and spikes.
Most frequently the pattern of inheritance indicates a recessive gene, but dominant and codominant mutations also appear.
Their unique hair and skin pigmentation is caused by the presence of a recessive gene known as chinchilla or colour inhibitor.
I was also astonished to learn that it's a recessive gene, which means both my husband and I gave our son his copper colored locks," Giladi said.
It can't just be that research for Newsnight has uncovered the frankly less-than-startling fact that children born to in-bred families are 13 times more likely to have recessive gene illnesses than the general population.