A centromere satellite concomitant with extensive karyotypic diversity across the Peromyscus genus defies predictions of molecular drive.

A centromere satellite concomitant with extensive karyotypic diversity across the Peromyscus genus defies predictions of molecular drive.
Chromosome Res. 2019 Feb 15;:
Authors: Smalec BM, Heider TN, Flynn BL, O'Neill RJ
Abstract
A common feature of eukaryotic centromeres is the presence of large tracts of tandemly arranged repeats, known as satellite DNA. However, these centromeric repeats appear to experience rapid evolution under forces such as molecular drive and centromere drive, seemingly without consequence to the integrity of the centromere. Moreover, blocks of heterochromatin within the karyotype, including the centromere, are hotspots for chromosome rearrangements that may drive speciation events by contributing to reproductive isolation. However, the relationship between the evolution of heterochromatic sequences and the karyotypic dynamics of these regions remains largely unknown. Here, we show that a single conserved satellite DNA sequence in the order Rodentia of the genus Peromyscus localizes to recurrent sites of chromosome rearrangements and heterochromatic amplifications. Peromyscine species display several unique features of chromosome evolution compared to other Rodentia, including stable maintenance of a strict chromosome number of 48 among all known species in the absence of any detectable interchromosomal rearrangements. Rather, the diverse karyotypes of Peromyscine species are due to intrachromosomal variation ...

Source: Chromosome Research - February 15, 2019 Category: Genetics & Stem Cells Authors: Smalec BM, Heider TN, Flynn BL, O'Neill RJ Tags: Chromosome Res Source Type: research