Horizontale Genoverdracht

Horizontal gene transfer, or HGT, moves genes between organisms of the same generation, unlike vertical gene transfer, which passes genes to offspring.

HGT is facilitated by mobile genetic elements such as plasmids, prophages, integrons, insertion sequences, and transposons.

Three mechanisms drive HGT. Transformationoccurs when a recipient cell directly takes foreign DNA from the surrounding environment.

In conjugation, cell-to-cell contact directly transfers DNA from host to recipient. In transduction, a bacteriophage mediates DNA transfer.

Upon uptake, foreign DNA is integrated through recombination, with RecA facilitating strand exchange, creating a recombinant hybrid.

Genes related to metabolism, virulence, or resistance commonly transfer through HGT in microbes within shared environments such as the human gut.

HGT contributes to the formation of pathogenicity islands – clusters of toxin, or virulence-related genes – that enhance pathogenicity in certain strains.

In some archaea, acquired DNA aids in UV damage repair, enabling rapid adaptation in extreme environments.