Shattuck Milena R, Satkoski-Trask Jessica, Deinard Amos, Tito Raul Y, Smith David G, Malhi Ripan S
Department of Anthropology, University of Illinois, Urbana, IL, 61801.
Am J Phys Anthropol. 2014 Apr;153(4):605-16. doi: 10.1002/ajpa.22460. Epub 2013 Dec 24.
Serotonin has been repeatedly indicated as a biological marker of behavior. In particular, the serotonin transporter gene, SLC6A4, has been the focus of a large body of research. Interestingly, both rhesus macaques (Macaca mulatta) and humans have independently evolved a number of shared polymorphisms for this gene, which is indicative of parallel evolution between the two species. However, little is known about the evolution of this gene, particularly within macaques. Although there are several hypotheses as to the adaptive values of various polymorphisms, few authors have gone beyond theoretical discussion. Here, we examined the genetic variation in SLC6A4 within and between several species of macaques and investigate whether selection has played a significant role in its evolutionary history. In addition, we assayed the promoter region polymorphism, 5-HTTLPR, which is known to play a significant role in regulating both serotonin turnover and behavior. In examining the distribution of the 5-HTTLPR polymorphism, we identified significant differences between Indian and Chinese populations of Macaca mulatta; furthermore, we discovered its presence in Macaca cyclopis, which has not been described before. In regard to the evolutionary history of SLC6A4, we found little evidence for selection and conclude that SLC6A4 largely evolved through neutral processes, possibly due to its potential role in regulating behavioral plasticity. However, we also found very low levels of linkage between the coding regions and 5-HTTLPR. Because we limited evolutionary analyses to the coding regions, it is possible that the promoter region shows a distinct evolutionary history from SLC6A4.
血清素一直被反复指出是行为的生物学标志物。特别是血清素转运体基因SLC6A4，一直是大量研究的焦点。有趣的是，恒河猴（猕猴）和人类独立地为该基因进化出了一些共同的多态性，这表明这两个物种之间存在平行进化。然而，关于该基因的进化，尤其是猕猴体内的进化，人们了解甚少。尽管对于各种多态性的适应价值有几种假说，但很少有作者超越理论探讨。在这里，我们研究了几种猕猴物种内部和之间SLC6A4的遗传变异，并调查选择是否在其进化历史中发挥了重要作用。此外，我们检测了启动子区域多态性5-HTTLPR，已知它在调节血清素周转和行为方面发挥重要作用。在研究5-HTTLPR多态性的分布时，我们发现印度和中国猕猴种群之间存在显著差异；此外，我们在台湾猕猴中发现了它的存在，此前尚未有过相关描述。关于SLC6A4的进化历史，我们几乎没有发现选择的证据，并得出结论，SLC6A4主要通过中性过程进化，这可能是由于其在调节行为可塑性方面的潜在作用。然而，我们也发现编码区和5-HTTLPR之间的连锁水平非常低。由于我们将进化分析限制在编码区，启动子区域可能显示出与SLC6A4不同的进化历史。
