DNA methylation reprogramming, TE derepression, and postzygotic isolation of nascent animal species

• DOI: 10.1126/sciadv.aaw1644
• Publication Date: 2019-10-16T23:24:10Z
• Authors: M. Laporte; J. Le Luyer; C. Rougeux; A.-M. Dion-Côté; M. Krick; L. Bernatchez
• Keywords: Derepression; Reprogramming; Isolation

The genomic shock hypothesis stipulates that the stress associated with divergent genome admixture can cause transposable element (TE) derepression, which could act as a postzygotic isolation mechanism. TEs affect gene structure, expression patterns, and chromosome organization may have deleterious consequences when released. For these reasons, they are silenced by heterochromatin formation, includes DNA methylation. Here, we show significant proportion of differentially methylated between "dwarf" (limnetic) "normal" (benthic) whitefish, two nascent species diverged some 15,000 generations ago within Coregonus clupeaformis complex. Moreover, overrepresented among loci were demethylated in hybrids, indicative their transcriptional derepression. These results consistent earlier studies this system revealed TE derepression causes abnormal embryonic development death hybrids. Hence, supports role methylation reprogramming animal species.