Radical amino acid mutations persist longer in the absence of sex |
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Authors: | Joel Sharbrough Meagan Luse Jeffrey L Boore John M Logsdon Jr Maurine Neiman |
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Institution: | 1. Department of Biology, University of Iowa, Iowa City, Iowa 52242;2. Department of Biology, Colorado State University, Fort Collins, Colorado 80523;3. Department of Integrative Biology, University of California, Berkeley, Berkeley, California 94720;4. Providence St. Joseph Health and Institute for Systems Biology, Seattle, Washington 98109 |
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Abstract: | Harmful mutations are ubiquitous and inevitable, and the rate at which these mutations are removed from populations is a critical determinant of evolutionary fate. Closely related sexual and asexual taxa provide a particularly powerful setting to study deleterious mutation elimination because sexual reproduction should facilitate mutational clearance by reducing selective interference between sites and by allowing the production of offspring with different mutational complements than their parents. Here, we compared the rate of removal of conservative (i.e., similar biochemical properties) and radical (i.e., distinct biochemical properties) nonsynonymous mutations from mitochondrial genomes of sexual versus asexual Potamopyrgus antipodarum, a New Zealand freshwater snail characterized by coexisting and ecologically similar sexual and asexual lineages. Our analyses revealed that radical nonsynonymous mutations are cleared at higher rates than conservative changes and that sexual lineages eliminate radical changes more rapidly than asexual counterparts. These results are consistent with reduced efficacy of purifying selection in asexual lineages allowing harmful mutations to remain polymorphic longer than in sexual lineages. Together, these data illuminate some of the population‐level processes contributing to mitochondrial mutation accumulation and suggest that mutation accumulation could influence the outcome of competition between sexual and asexual lineages. |
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Keywords: | Asexual reproduction mitochondrial genome Potamopyrgus antipodarum purifying selection selective interference sexual reproduction |
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