Massive expansion of sex-specific SNPs, transposon-related elements, and neocentromere formation shape the young W-chromosome from the mosquitofish Gambusia affinis.

ABSTRACT:

Background

The Western mosquitofish, Gambusia affinis, is a model for sex chromosome organization and evolution of female heterogamety. We previously identified a G. affinis female-specific marker, orthologous to the aminomethyl transferase (amt) gene of the related platyfish (Xiphophorus maculatus). Here, we have analyzed the structure and differentiation of the G. affinis W-chromosome, using a cytogenomics and bioinformatics approach.

Results

The long arm of the G. affinis W-chromosome (Wq) is highly enriched in dispersed repetitive sequences, but neither heterochromatic nor epigenetically silenced by hypermethylation. In line with this, Wq sequences are highly transcribed, including an active nucleolus organizing region (NOR). Female-specific SNPs and evolutionary young t

SUBMITTER: Muller S 

PROVIDER: S-EPMC10186657 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature