The nanopore sequencing of a Chinese rhesus macaque revealed patterns of
methylation, recombination, and selection for structural variations
Abstract
Rhesus macaque (Macaca mulatta) is the most extensively studied nonhuman
primate species for human biomedical modeling. However, little is known
about the biological pattern of genome-wide structural variations (SVs)
and the evolutionary forces underlying SVs in this species. Here, we
conducted genomic sequencing and analyses based on Nanopore long-reads
and Illumina short-reads technologies. We called SVs between the two
subspecies (China vs. India), using three methods of assembly-based and
long-reads-based algorithms. Interestingly, we found significantly more
SVs in the X-chromosome than in autosomes, consistent with the
expectation of the faster-X divergence at the subspecies level. With the
fine-scale methylation frequencies and recombination rates, we found
duplications with significantly lower methylation frequencies while
higher recombination rates than other types of SVs, suggesting a higher
level of transcriptional and evolutionary potential for duplications
than for other SVs types. A genome-wide scan of selective sweeps
revealed that over 3% of SVs are under positive selection and that X
chromosome showed significantly higher number of positively selected SVs
than do autosomes, suggesting the “faster-X effect” of SVs. Thus, our
study revealed a different evolutionary importance of duplications
compared with other SVs forms in producing raw material upon which
selective forces, including the faster-X effect, can further play.