Mechanisms of intron loss and gain in the fission yeast Schizosaccharomyces.

ABSTRACT: The fission yeast, Schizosaccharomyces pombe, is an important model species with a low intron density. Previous studies showed extensive intron losses during its evolution. To test the models of intron loss and gain in fission yeasts, we conducted a comparative genomic analysis in four Schizosaccharomyces species. Both intronization and de-intronization were observed, although both were at a low frequency. A de-intronization event was caused by a degenerative mutation in the branch site. Four cases of imprecise intron losses were identified, indicating that genomic deletion is not a negligible mechanism of intron loss. Most intron losses were precise deletions of introns, and were significantly biased to the 3' sides of genes. Adjacent introns tended to be lost simultaneously. These observ

SUBMITTER: Zhu T 

PROVIDER: S-EPMC3629103 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature