DNA gains and losses in gigantic genomes do not track differences in transposable element-host silencing interactions.

ABSTRACT: Size evolution among gigantic genomes involves gain and loss of many gigabases of transposable elements (TEs), sequences that parasitize host genomes. Vertebrates suppress TEs using piRNA and KRAB-ZFP pathways. TEs and hosts coevolve in an arms race, where suppression strength reflects TE fitness costs. In enormous genomes, additional TE costs become miniscule. How, then, do TEs and host suppression invoke further addition of massive DNA amounts? We analyze TE proliferation histories, deletion rates, and community diversities in six salamander genomes (21.3 - 49.9 Gb), alongside gonadal expression of TEs and suppression pathways. We show that TE activity is higher in testes than ovaries, attributable to lower KRAB-ZFP suppression. Unexpectedly, genome size and expansion are uncorrelated wi

SUBMITTER: Wang J 

PROVIDER: S-EPMC12056039 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature