Kopplungsgruppe

Kopplungsgruppe refers to a group of genes on the same chromosome in an organism that tend to be inherited together. This phenomenon is due to their physical proximity on the chromosome. Genes located close to each other are less likely to be separated during the process of meiotic recombination, also known as crossing over.

The concept of linkage and coupling groups is fundamental in genetics and was first observed by William Bateson and Reginald Punnett early in the 20th century. They noticed that certain traits, controlled by genes on the same chromosome, did not segregate independently as predicted by Mendel's laws. Instead, they were inherited in patterns that suggested a linkage.

The size and number of coupling groups in an organism correspond to its number of chromosomes. For example, a diploid organism with n pairs of chromosomes will have n coupling groups. These groups are often referred to as linkage groups. Studying these groups helps geneticists understand chromosome structure, map gene locations, and predict inheritance patterns of complex traits.

Linkage can be complete, meaning genes are always inherited together, or incomplete, where recombination can occasionally separate them. The degree of linkage is inversely proportional to the distance between the genes on the chromosome. Genes that are very far apart on the same chromosome may exhibit independent assortment due to a high probability of recombination occurring between them. Understanding coupling groups is crucial for breeding programs and for identifying genes associated with diseases or desirable characteristics.