作者: King Jordan , John F. McDonald
DOI: 10.1007/978-94-011-4156-7_2
关键词: Phylogenetic tree 、 Biology 、 Genome 、 Genomics 、 Genetics 、 Retrotransposon 、 Whole genome sequencing 、 Molecular evolution 、 Nonsynonymous substitution 、 Comparative genomics
摘要: The availability of the complete genome sequence Saccharomyces cerevisiae provides unique opportunity to study an entire genomic complement retrotransposons from evolutionary perspective. There are five families yeast retrotransposons, Ty1-Ty5. We have conducted a series comparative analyses within and among S. Ty in effort document forces that shaped element variation. Our results indicate elements vary little terms both size sequence. Furthermore, intra-element 5′-3′ long terminal repeat (LTR) comparisons almost all recently transposed. For each family, solo LTR sequences generated by recombination far outnumber full length insertions. Taken together, these suggest rapid turnover elements. closely related Ty1 Ty2 most numerous genome. Phylogenetic analysis insertions reveals reverse transcriptase mediated between has number hybrid Ty1/2 These similar structures with chimeric LTRs TYB (pol) genes. Analysis levels nonsynonymous (Ka) synonymous (Ks) nucleotide variation indicates coding regions been subject strong negative (purifying) selection. Distribution Ka Ks on Ty1, phytogenies evidence selection internal external branches. This pattern suggests majority represent active or lineages is consistent high level turnover. dynamics cerevisae uncovered our discussed respect interaction their host