Rekombinationsreaktionsschalter

Rekombination is a fundamental process in genetics. It refers to the rearrangement of genetic material, either by exchange of genetic material between different chromosomes or between different regions within the same chromosome. This shuffling of genes leads to new combinations of alleles, which are different versions of a gene.

In sexually reproducing organisms, homologous recombination is a key mechanism. During meiosis, the process of cell division that produces gametes (sperm and egg cells), homologous chromosomes pair up. Segments of DNA can then be exchanged between these paired chromosomes. This exchange, known as crossing over, results in chromosomes with novel combinations of alleles that were not present in either parent chromosome. This genetic variation is crucial for evolution, as it provides a wider range of traits for natural selection to act upon.

Another form of recombination is site-specific recombination, which occurs at specific DNA sequences mediated by enzymes called recombinases. This process is important in various cellular functions, including DNA repair, viral integration into host genomes, and the development of the immune system in vertebrates. Non-homologous end joining is a mechanism for repairing double-strand breaks in DNA, and while not strictly recombination, it can also lead to chromosomal rearrangements. The precise mechanisms and significance of recombination continue to be areas of active research in molecular biology.