In the following analysis, we masked regions with lower and higher coverage than cut-off values. Stratum two had a significantly lower d N than the other strata. C Significant QTL were found for hybrid courtship abnormality. The centromere paradox: stable inheritance with rapidly evolving DNA.
These results suggest that neo-sex chromosome formation may create a genomic location where mutations causing inter-species differences can accumulate, thereby promoting phenotypic divergence between incipient species.
First, the sequenced tree, Nisqually-1, is a female, and it showed highly divergent haplotypes in the sex determination region. Rowland, D. With these techniques, researchers have identified differences and similarities in sex chromosome content and organization across amniotes and have addressed evidence for sex chromosome evolution in Seattle regarding the frequency and direction of past changes.
Sex-chromosome turnovers: the hot-potato model. In contrast to theory, advances in empirical data have been enormous since the s thanks to the advent of genomic methods.
Smith, K. The techniques needed to detect sex chromosomes depend in part on the evolutionary history of the sex chromosome pair. Yang Z. Surprisingly, it was initially assumed that the Drosophila and human XY chromosomes are homologous [ 18 ].
View at: Google Scholar. Therefore, incipient sex chromosomes should show regions of suppressed recombination with high levels of haplotype divergence. Marshall Graves, A. Through these assemblies, two classes of genes have been identified on highly degenerate and relatively old sex chromosomes.
Sayres MAW. We therefore recommend a greater focus on the role of ecology and demography in sex chromosome evolution.