Developmental timing of programmed DNA elimination in Paramecium tetraurelia recapitulates germline transposon evolutionary dynamics.

ABSTRACT: With its nuclear dualism, the ciliate Paramecium constitutes a unique model to study how host genomes cope with transposable elements (TEs). P. tetraurelia harbors two germline micronuclei (MICs) and a polyploid somatic macronucleus (MAC) that develops from one MIC at each sexual cycle. Throughout evolution, the MIC genome has been continuously colonized by TEs and related sequences that are removed from the somatic genome during MAC development. Whereas TE elimination is generally imprecise, excision of approximately 45,000 TE-derived internal eliminated sequences (IESs) is precise, allowing for functional gene assembly. Programmed DNA elimination is concomitant with genome amplification. It is guided by noncoding RNAs and repressive chromatin marks. A subset of IESs is exci

SUBMITTER: Zangarelli C 

PROVIDER: S-EPMC9808624 | biostudies-literature | 2022 Nov-Dec

REPOSITORIES: biostudies-literature