Rekombinaation

Rekombination, often rendered as recombination in English, refers to the natural process by which genetic material is exchanged, rearranged, or repaired within or between DNA molecules. It occurs in a wide range of organisms, from viruses and bacteria to plants and animals, and serves as a fundamental mechanism for generating genetic diversity, repairing damaged DNA, and facilitating adaptation.

In cellular biology, rekombination can be classified into several types. Homologous recombination involves the exchange of nucleotide sequences between regions of high similarity, typically during meiosis, where it promotes the shuffling of alleles and ensures proper chromosome segregation. Non‑homologous end joining (NHEJ) joins DNA ends with little or no sequence homology and is a primary pathway for repairing double‑strand breaks in somatic cells. Site‑specific recombination utilizes specialized enzymes, such as integrases or transposases, to insert, delete, or invert DNA segments at defined loci, a process exploited by many viruses and mobile genetic elements.

The molecular machinery driving rekombination includes recombinases, helicases, nucleases, and ligases. In eukaryotes, the RecA homologs Rad51 and Dmc1 orchestrate strand invasion during homologous recombination, while the Ku70/80 complex and DNA‑PK facilitate NHEJ. In prokaryotes, the RecA protein performs analogous functions, aiding both recombination and the SOS response to DNA damage.

Rekombination has practical implications beyond basic biology. It underlies techniques such as genetic mapping, gene targeting, and the creation of transgenic organisms. In medicine, aberrant recombination can contribute to oncogenesis, immunoglobulin diversity, and the emergence of antimicrobial resistance. Understanding its mechanisms continues to inform biotechnology, evolutionary theory, and therapeutic development.