Abstract:

Given the stable and heritable individual differences in animal behaviors, personality is associated with the polymorphisms of related genes and reflects the adaptation patterns of animals to variable environments. Exploring the variations in personality-related genes will contribute to the improved understanding of the evolutionary and adaptation mechanisms of animals’ response to environments. In this study, we used plateau pikas (Ochotona curzoniae) inhabiting five altitudinal regions of the Qinghai–Tibetan Plateau as study objects to determine their personality variations, explore the associations between single nucleotide polymorphisms (SNP) of serotonin transporter (SERT) and personality, and obtain the expression level of the SERT gene. Results showed that the exploration and boldness of pikas at high altitudes were significantly higher than those at low altitudes, whereas the expression level of SERT at high altitudes was significantly lower than that at low altitudes, suggesting that the personality of pikas in different altitudes might be correlated with the mRNA expression of the SERT gene. Furthermore, SERT gene polymorphisms and their distribution differences among different altitudes were detected. Six SNP mutations were detected in the SERT gene (5 and 1 SNP mutations were located in exons 3 and 5, respectively). Significant correlations between c.A1063C synonymous mutation in exon 5 and altitudes were observed, suggesting that the distribution frequencies of the CC genotype of c.A1063C at high altitudes were significantly higher than those at low altitudes. No significant correlation between c.A1063C genotypes and exploration or boldness was observed, whereas significant correlations between c.A1063C genotypes and docility were detected. Our results suggested that with increasing altitude, the exploration and boldness of plateau pikas increased for food resource and survival opportunities to adapt to environments at different altitudes and that the difference in docility might be related to the synonymous mutation of exon 5 of the SERT gene c.A1063C. This study attempted to elaborate on the differences in personality of plateau pikas adapted to different altitudes from the perspective of gene expression and mutation, providing the potential molecular mechanism of plateau pika’s behavioral strategies at different altitudes.

Key words: Personality, Altitude, Serotonin transporter, Plateau pikas (Ochotona curzoniae)

摘要：

个性特征是指动物个体间稳定、可遗传的行为差异，与相关基因多态性有关，反映了动物对环境的适应模式，探究个性相关基因变异，将有助于更好地理解动物对环境的适应与进化机制。本文以高原鼠兔 (Ochotona curzoniae) 为对象，研究了5个不同海拔地区高原鼠兔的个性 (探究性、勇敢性和温顺性) 差异特征，并检测了个性相关基因5-羟色胺转运体 (SERT) 的单核苷酸多态性 (SNP) 和mRNA表达。结果发现，高海拔地区高原鼠兔的探究性和勇敢性显著高于低海拔地区，而高海拔地区高原鼠兔SERT基因mRNA表达量显著低于低海拔地区，提示不同海拔高原鼠兔个性特征差异可能与SERT基因mRNA表达有所关联。进一步检测不同海拔地区高原鼠兔SERT基因多态性及其分布差异情况，发现该基因存在6个SNP (其中5个位于外显子3，1个位于外显子5 )；不同海拔地区鼠兔基因分布差异分析显示外显子5的c.A1063C 同义突变与海拔之间存在显著相关，高海拔地区该位点CC基因型分布频率显著高于低海拔地区；c.A1063C的基因型虽然与探究性、勇敢性无显著相关，但与温顺性显著相关。综上所述，随着海拔升高，高原鼠兔探究性和勇敢性增加，这有利于动物获取更多的食物资源，进而增加其生存机会。与此同时，SERT基因多态性显示与不同海拔地区的生存环境相适应的特征，且与温顺性有关，暗示不同海拔高原鼠兔个性差异可能与SERT基因SNP的差异有关。本研究从基因表达与突变的角度尝试阐述高原鼠兔适应不同海拔环境的行为差异，显示了不同海拔地区高原鼠兔行为生存策略潜在的分子机制。

关键词: 个性特征, 海拔, 5-羟色胺转运体, 高原鼠兔