recombination

/ree'kom beuh nay"sheuhn/, Genetics.

the formation of new combinations of genes, either naturally, by crossing over or independent assortment, or in the laboratory by direct manipulation of genetic material.

[1820-30, for general sense; 1900-05 for current sense; RE- + COMBINATION]

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In genetics, regrouping of the maternal and paternal genes during the formation of sex cells (gametes).

Recombination occurs randomly in nature as a normal event of meiosis. It is enhanced by crossing-over (see linkage group). Recombination acts to ensure that no two daughter cells are identical, nor are any identical in genetic content to the parent cell. Laboratory study of recombination has contributed significantly to the understanding of genetic mechanisms, allowing scientists to map chromosomes, identify linkage groups, isolate the causes of certain genetic mistakes, and manipulate recombination itself by transplanting genes from one chromosome to another. See also genetic engineering, molecular biology.

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▪ genetics

      in genetics, regrouping of the maternal and paternal genes during the formation of gametes (gamete) (sex cells). Recombination occurs randomly in nature as a normal event of meiosis, the process by which gametes are produced. Recombination is enhanced by the phenomenon of crossing over, in which gene sequences called linkage groups are disrupted, resulting in an exchange of segments between paired chromosomes that are undergoing separation. Thus, although a normal daughter cell produced in meiosis always receives half of the genetic material contained in the parent cell (i.e., is haploid), recombination acts to ensure constant variability: no two daughter cells are identical, nor are any identical in genetic content to the parent cell.

      Laboratory study of recombination has contributed significantly to the understanding of genetic mechanisms, allowing scientists to map chromosomes, identify linkage groups, isolate the causes of certain genetic anomalies, and manipulate recombination itself by transplantation of genes from one chromosome to another. Because of its potential for creating new—and possibly pathogenic—organisms, experimental recombination is viewed by some scientists as both dangerous and unethical.

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