Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, USA.
PLoS One. 2013;8(1):e52282. doi: 10.1371/journal.pone.0052282. Epub 2013 Jan 24.
A premature stop codon in ACTN3 resulting in α-actinin-3 deficiency (the ACTN3 577XX genotype) is common in humans and reduces strength, muscle mass, and fast-twitch fiber diameter, but increases the metabolic efficiency of skeletal muscle. Linkage disequilibrium data suggest that the ACTN3 R577X allele has undergone positive selection during human evolution. The allele has been hypothesized to be adaptive in environments with scarce resources where efficient muscle metabolism would be selected. Here we test this hypothesis by using recently developed comparative methods that account for evolutionary relatedness and gene flow among populations. We find evidence that the ACTN3 577XX genotype evolved in association with the global latitudinal gradient. Our results suggest that environmental variables related to latitudinal variation, such as species richness and mean annual temperature, may have influenced the adaptive evolution of ACTN3 577XX during recent human history.
肌球蛋白重链 3 基因中的一个过早终止密码子导致 α-辅肌动蛋白-3 缺乏（ACTN3 577XX 基因型）在人类中很常见，它会降低力量、肌肉质量和快肌纤维直径，但会增加骨骼肌的代谢效率。连锁不平衡数据表明，ACTN3 R577X 等位基因在人类进化过程中经历了正选择。该等位基因被假设在资源匮乏的环境中是适应性的，在这种环境中，高效的肌肉代谢将被选择。在这里，我们使用最近开发的比较方法来检验这一假设，该方法考虑了种群之间的进化关系和基因流动。我们发现证据表明，ACTN3 577XX 基因型的进化与全球纬度梯度有关。我们的结果表明，与纬度变化相关的环境变量，如物种丰富度和年平均温度，可能影响了 ACTN3 577XX 在人类近代历史上的适应性进化。
