Oxytocin and arginine vasopressin systems in the domestication process

Abstract Domestication is of unquestionable importance to the technological revolution that has given rise to modern human societies. In this study, we analyzed the DNA and protein sequences of six genes of the oxytocin and arginine vasopressin systems (OXT-OXTR; AVP-AVPR1a, AVPR1b and AVPR2) in 40 placental mammals. These systems play an important role in the control of physiology and behavior. According to our analyses, neutrality does not explain the pattern of molecular evolution found in some of these genes. We observed specific sites under positive selection in AVPR1b (ω = 1.429, p = 0.001) and AVPR2 (ω= 1.49, p = 0.001), suggesting that they could be involved in behavior and physiological changes, including those related to the domestication process. Furthermore, AVPR1a, which plays a role in social behavior, is under relaxed selective constraint in domesticated species. These results provide new insights into the nature of the domestication process and its impact on the OXT-AVP system.

摘要 驯化对于催生现代人类社会的技术革命具有毋庸置疑的重要意义。本研究针对40种胎盘哺乳动物（placental mammals）的催产素（oxytocin, OXT）与精氨酸加压素（arginine vasopressin, AVP）系统的6个基因（OXT-OXTR；AVP-AVPR1a、AVPR1b及AVPR2）的DNA与蛋白质序列展开分析。该系统在生理与行为调控中发挥关键作用。分析结果显示，中性演化无法解释部分基因的分子进化模式。我们在AVPR1b（ω=1.429，p=0.001）与AVPR2（ω=1.49，p=0.001）中检测到受正向选择（positive selection）的特定位点，提示这两个基因可能参与包括驯化过程相关在内的行为与生理变化。此外，参与社会行为调控的AVPR1a在驯化物种中呈现选择约束放松的特征。本研究结果为驯化过程的本质及其对OXT-AVP系统的影响提供了新的认知视角。