Zhan X J, Zhang Z J, Wu H, Goossens B, Li M, Jiang S W, Bruford M W, Wei F W
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 25 Beisihuan Xilu, Beijing 100080, China.
Mol Ecol. 2007 Sep;16(18):3792-800. doi: 10.1111/j.1365-294X.2007.03450.x.
Although dispersal in the giant panda (Ailuropoda melanoleuca) is a demographic mechanism which can potentially counteract the negative effect of habitat fragmentation, little is known about dispersal in this species because of difficulties in observing individuals. Using data from faecal microsatellite genotyping, we compared the spatial distribution of giant pandas in two populations and the proximity of relatives in one key population to infer their dispersal pattern. We conclude that giant pandas exhibit female-biased dispersal because: (i) vAIc (variance of assignment index) for females was significantly larger than for males, suggesting that females comprise both 'local' and 'foreign' genotypes; (ii) the average spatial distance of related female dyads was significantly larger than that of males; (iii) larger r (relatedness), F(ST) (genetic variance among populations) and mAIc (mean of assignment index) values were found in males using the software FSTAT, although the differences were not significant; (iv) males set up territories neighbouring to their birth place; (v) significant population structure using microsatellites with a concomitant lack of mitochondrial structure was found in a previous study, possibly indicating more extensive female dispersal; and (vi) female-biased dispersal was strongly supported by evidence from concomitant ecological studies. Considering previous ecological data and life-history characteristics of the giant panda, female-biased dispersal is most likely to be due to competition for birth dens among females, inbreeding avoidance and enhancing inclusive fitness among related males.
尽管大熊猫（Ailuropoda melanoleuca）的扩散是一种人口统计学机制，有可能抵消栖息地破碎化的负面影响，但由于观察个体存在困难，对该物种的扩散情况知之甚少。我们利用粪便微卫星基因分型数据，比较了两个大熊猫种群的空间分布以及一个关键种群中亲属的亲近程度，以推断它们的扩散模式。我们得出结论，大熊猫表现出雌性偏向扩散，原因如下：（i）雌性的vAIc（分配指数方差）显著大于雄性，这表明雌性包含“本地”和“外地”基因型；（ii）相关雌性二元组的平均空间距离显著大于雄性；（iii）使用FSTAT软件在雄性中发现了更大的r（亲缘关系）、F(ST)（种群间遗传方差）和mAIc（分配指数均值）值，尽管差异不显著；（iv）雄性在其出生地附近建立领地；（v）在先前的一项研究中发现，使用微卫星存在显著的种群结构，同时缺乏线粒体结构，这可能表明雌性扩散更为广泛；（vi）伴随的生态研究证据有力支持了雌性偏向扩散。考虑到大熊猫先前的生态数据和生活史特征，雌性偏向扩散最有可能是由于雌性之间对出生巢穴的竞争、避免近亲繁殖以及提高相关雄性之间的广义适合度。
