Maximum-Likelihood Analysis of Molecular Adaptation in Abalone Sperm Lysin Reveals Variable Selective Pressures Among Lineages and Sites Export

@article{citeulike:395715, abstract = {Maximum-likelihood models of codon substitution were used to analyze sperm lysin genes of 25 abalone (Haliotis) species to identify lineages and amino acid sites under diversifying selection. The models used the nonsynonymous/synonymous rate ratio ({omega} = dN/dS) as an indicator of selective pressure and allowed the ratio to vary among lineages or sites. Likelihood ratio tests suggested significant variation in selective pressure among lineages. The variable selective pressure provided an explanation for the previous observation that the {omega} ratio is >1 in comparisons of closely related species and <1 in comparisons of distantly related species. Computer simulations demonstrated that saturation of nonsynonymous substitutions and constraint on lysin structure were unlikely to account for the observed pattern. Lineages linking closely related sympatric species appeared to be under diversifying selection, while lineages separating distantly related species from different geographic locations were associated with low evolutionary rates. The selective pressure indicated by the {omega} ratio was found to vary greatly among amino acid sites in lysin. Sites under potential diversifying selection were identified. Ancestral lysins were inferred to trace the route of evolution at individual sites and to provide lysin sequences for future laboratory studies.}, author = {Yang, Ziheng and Swanson, Willie J. and Vacquier, Victor D.}, citeulike-article-id = {395715}, citeulike-linkout-0 = {http://mbe.oxfordjournals.org/cgi/content/abstract/17/10/1446}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/11018152}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=11018152}, day = {1}, journal = {Mol Biol Evol}, keywords = {abalone, codon, likelihood, maximum, molevoltestis, paml, positive, selection, sperm, substitution}, month = {October}, number = {10}, pages = {1446--1455}, posted-at = {2008-06-06 16:21:33}, priority = {0}, title = {Maximum-Likelihood Analysis of Molecular Adaptation in Abalone Sperm Lysin Reveals Variable Selective Pressures Among Lineages and Sites}, url = {http://mbe.oxfordjournals.org/cgi/content/abstract/17/10/1446}, volume = {17}, year = {2000} }

TY - JOUR ID - citeulike:395715 L3 - citeulike-article-id:395715 N2 - Maximum-likelihood models of codon substitution were used to analyze sperm lysin genes of 25 abalone (Haliotis) species to identify lineages and amino acid sites under diversifying selection. The models used the nonsynonymous/synonymous rate ratio ({omega} = dN/dS) as an indicator of selective pressure and allowed the ratio to vary among lineages or sites. Likelihood ratio tests suggested significant variation in selective pressure among lineages. The variable selective pressure provided an explanation for the previous observation that the {omega} ratio is >1 in comparisons of closely related species and <1 in comparisons of distantly related species. Computer simulations demonstrated that saturation of nonsynonymous substitutions and constraint on lysin structure were unlikely to account for the observed pattern. Lineages linking closely related sympatric species appeared to be under diversifying selection, while lineages separating distantly related species from different geographic locations were associated with low evolutionary rates. The selective pressure indicated by the {omega} ratio was found to vary greatly among amino acid sites in lysin. Sites under potential diversifying selection were identified. Ancestral lysins were inferred to trace the route of evolution at individual sites and to provide lysin sequences for future laboratory studies. IS - 10 JF - Mol Biol Evol EP - 1455 TI - Maximum-Likelihood Analysis of Molecular Adaptation in Abalone Sperm Lysin Reveals Variable Selective Pressures Among Lineages and Sites VL - 17 SP - 1446 KW - abalone KW - codon KW - likelihood KW - maximum KW - molevoltestis KW - paml KW - positive KW - selection KW - sperm KW - substitution AU - Yang, Ziheng AU - Swanson, Willie AU - Vacquier, Victor PY - 2000/10/01/ UR - http://mbe.oxfordjournals.org/cgi/content/abstract/17/10/1446 ER -