Adaptive evolution of <it>SCML1 </it>in primates, a gene involved in male reproduction

• Main Authors: Wu Hai-hui, Su Bing
• Format: Article
• Language: English
• Published: BMC 2008-07-01
• Series: BMC Evolutionary Biology
• Online Access: http://www.biomedcentral.com/1471-2148/8/192

<p>Abstract</p> <p>Background</p> <p>Genes involved in male reproduction are often the targets of natural and/or sexual selection. <it>SCML1 </it>is a recently identified X-linked gene with preferential expression in testis. To test whether <it>SCML1 </it>is the target of selection in primates, we sequenced and compared the coding region of <it>SCML1 </it>in major primate lineages, and we observed the signature of positive selection in primates.</p> <p>Results</p> <p>We analyzed the molecular evolutionary pattern of <it>SCML1 </it>in diverse primate species, and we observed a strong signature of adaptive evolution which is caused by Darwinian positive selection. When compared with the paralogous genes (<it>SCML2 and SCMH1</it>) of the same family, <it>SCML1 </it>evolved rapidly in primates, which is consistent with the proposed adaptive evolution, suggesting functional modification after gene duplication. Gene expression analysis in rhesus macaques shows that during male sexual maturation, there is a significant expression change in testis, implying that <it>SCML1 </it>likely plays a role in testis development and spermatogenesis. The immunohistochemical data indicates that <it>SCML1 </it>is preferentially expressed in germ stem cells of testis, therefore likely involved in spermatogenesis.</p> <p>Conclusion</p> <p>The adaptive evolution of <it>SCML1 </it>in primates provides a new case in understanding the evolutionary process of genes involved in primate male reproduction.</p>