Degeneration in codon usage within the region of suppressed recombination in the mating-type chromosomes of Neurospora tetrasperma.

ABSTRACT: The origin and early evolution of sex chromosomes are currently poorly understood. The Neurospora tetrasperma mating-type (mat) chromosomes have recently emerged as a model system for the study of early sex chromosome evolution, since they contain a young (<6 million years ago [Mya]), large (>6.6-Mb) region of suppressed recombination. Here we examined preferred-codon usage in 290 genes (121,831 codon positions) in order to test for early signs of genomic degeneration in N. tetrasperma mat chromosomes. We report several key findings about codon usage in the region of recombination suppression, including the following: (i) this region has been subjected to marked and largely independent degeneration among gene alleles; (ii) the level of degeneration is magnified over longer periods of recom

SUBMITTER: Whittle CA 

PROVIDER: S-EPMC3127651 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature