Transitions to Asexuality Result in Excess Amino Acid Substitutions

@article{citeulike:507934, abstract = {Theory predicts that linkage between genetic loci reduces the efficiency of purifying selection. Because of the permanent linkage of all heritable genetic material, asexual lineages may be exceptionally prone to deleterious-mutation accumulation in both nuclear and organelle genes. Here, we show that the ratio of the rate of amino acid to silent substitution (Ka/Ks) in mitochondrial protein-coding genes is higher in obligately asexual lineages than in sexual lineages of the microcrustacean Daphnia pulex. Using a phylogeny-based approach to quantify the frequency of mutational-effect classes, we estimate that mitochondrial protein-coding genes in asexual lineages accumulate deleterious amino acid substitutions at four times the rate in sexual lineages. These results support the hypothesis that sexual reproduction plays a prominent role in reducing the mutational burden in populations.}, author = {Paland, Susanne and Lynch, Michael }, citeulike-article-id = {507934}, doi = {http://dx.doi.org/10.1126/science.1118152}, journal = {Science}, keywords = {invertebrate}, month = {February}, number = {5763}, pages = {990--992}, posted-at = {2006-02-23 23:34:21}, priority = {2}, title = {Transitions to Asexuality Result in Excess Amino Acid Substitutions}, url = {http://dx.doi.org/10.1126/science.1118152}, volume = {311}, year = {2006} }

TY - JOUR ID - citeulike:507934 L3 - citeulike-article-id:507934 TI - Transitions to Asexuality Result in Excess Amino Acid Substitutions JF - Science VL - 311 IS - 5763 SP - 990 EP - 992 N2 - Theory predicts that linkage between genetic loci reduces the efficiency of purifying selection. Because of the permanent linkage of all heritable genetic material, asexual lineages may be exceptionally prone to deleterious-mutation accumulation in both nuclear and organelle genes. Here, we show that the ratio of the rate of amino acid to silent substitution (Ka/Ks) in mitochondrial protein-coding genes is higher in obligately asexual lineages than in sexual lineages of the microcrustacean Daphnia pulex. Using a phylogeny-based approach to quantify the frequency of mutational-effect classes, we estimate that mitochondrial protein-coding genes in asexual lineages accumulate deleterious amino acid substitutions at four times the rate in sexual lineages. These results support the hypothesis that sexual reproduction plays a prominent role in reducing the mutational burden in populations. KW - invertebrate AU - Paland, Susanne AU - Lynch, Michael PY - 2006/02/17/ UR - http://dx.doi.org/10.1126/science.1118152 ER -