舟山群岛黄毛鼠种群的遗传多样性及多重父权研究

岛屿常被生态学家和进化生物学家视为研究生物进化的天然实验室。本研究利用微卫星分子标记技术,分析了舟山群岛优势鼠种——黄毛鼠(Rattus losea)刺山岛种群、六横岛种群、桃花岛种群3个种群的遗传多样性,并探讨该物种是否存在多重父权现象。研究结果表明,(1)黄毛鼠种群的平均观测等位基因数(NA)和平均有效等位基因数(Ne)分别为8.792和5.494,平均期望杂合度(He)和平均观测杂合度(Ho)分别为0.821和0.956,多态信息含量(PIC)均大于0.5,说明3个种群均具有较高的遗传多样性;(2)3个种群的平均遗传分化系数(Fst)为0.040,其中桃花岛种群与刺山岛种群的分化最大,分化系数为0.052,呈中度分化水平,不同种群间所贡献的变异百分数为3.98%,说明遗传变异主要发生在种群内,而种群间仅存在很小的遗传变异;(3)14只孕鼠中,有6只孕鼠的胚胎存在多重父权现象,占43%,最小父本值为2,其余8个孕鼠的胚胎均只有唯一父本。本研究提出黄毛鼠存在多重父权现象,为该物种繁殖策略及鼠害控制的研究提供依据。

Genetic Diversity and Multiple Paternity of Rattus losea in Zhoushan Archipelago

Islands are often regarded as natural laboratories for the study of biological evolution by ecologists and evolutionary biologists. Based on microsatellite molecular marker technology, we analyzed the genetic diversity of three Rattus losea populations in Zhoushan Archipelago, and calculated the related genetic parameters and the coefficient of genetic differentiation with the software POPGEN 32 and ARLEQUIN 3.0, respectively. We also calculated the minimum paternal value with the software GERUD 2.0, and found the existence of multiple paternity. The results were as following: (1) The average observed number of alleles (NA) and the average effective number of alleles (Ne) were 8.792 and 5.494, respectively (Table 2); the average expected heterozygosity (He) and the average observed heterozygosity (Ho) were 0.821 and 0.956, respectively; the polymorphism information content (PIC) were larger than 0.5 (Table 2), which indicated that three populations had a high degree of genetic diversity. (2) The average genetic differentiation value among three populations was 0.040, and the value between Taohua island and Cishan island was the largest (Fst = 0.052), showing a moderate level of differentiation. The percentage of variation among three populations accounted for 3.98% (Table 4), which indicated that the differentiation occurred mainly within the populations. (3) Six out of the fourteen pregnant rats (43%) had their embryos with multiple paternity (Fig. 3). The minimum paternal value was 2 (Table 5), and the embryos of the other pregnant rats had only one father. This study proposed the existence of multiple paternity phenomenon of R. losea populations in Zhoushan Archipelago, and provided useful information for the study of reproductive strategy and pest control of R. losea populations.