Microsatellite analysis of genetic diversity in the Chinese alligator (Alligator sinensis) Changxing captive population
Microsatellite analysis of genetic diversity in the Chinese alligator (Alligator sinensis) Changxing captive population
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DOI：
10.1007/s10592-005-9081-x
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发表时间：
2006-02
影响因子：
2.2
通讯作者：
Qianghua Xu;S. Fang;Zhiping Wang;Zhenwei Wang
中科院分区：
文献类型：
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作者：
Qianghua Xu;S. Fang;Zhiping Wang;Zhenwei Wang
扬子鳄（Alligator sinensis）是我国特有的极危物种。本研究利用美洲鳄微卫星标记对长兴保护区圈养扬子鳄的遗传变异程度进行了研究。在22个基因座中，有21个基因座在扬子鳄中扩增成功。序列分析表明，美洲鳄的基因座平均大小大于扬子鳄，且单个基因座的最长等位基因几乎总是存在于重复单位长度较长的物种中。22个位点中的8个被发现是多态的，在32只动物中总共存在26个等位基因，每个多态位点平均产生3.25个等位基因。该群体的期望杂合度（HE）介于0.4385 ~ 0.7163之间，处于中等水平。与美洲鳄相比，长兴鳄群体的微卫星多样性水平较低，每个位点的等位基因数减少了46%，同源位点的平均等位基因数也较小。评估这些标记的平均排除能力和检测共享基因型和多重亲子关系的能力。结果表明，当多态位点组合时，它们可以作为敏感的标记用于扬子鳄群体内的遗传多样性研究和亲缘关系推断。目前长兴居群的遗传多样性水平表明，长兴居群的遗传多样性水平是补充其他居群个体再引入的重要资源。此外，微卫星标记及其相关的多样性特征在该群体中可以用来进一步研究该物种的遗传状态。
Chinese alligator (Alligator sinensis) is a critically endangered species endemic to China. In this study, the extent of genetic variation in the captive alligators of the Changxing Reserve Center was investigated using microsatellite markers derived from American alligators. Out of 22 loci employed, 21 were successfully amplified in the Chinese alligator. Sequence analysis showed loci in American alligators had a bigger average size than that of the Chinese alligators and the longest allele of an individual locus almost always existed in the species with longer stretch of repeat units. Eight of the 22 loci were found to be polymorphic with a total of 26 alleles present among 32 animals scored, yielding an average of 3.25 alleles per polymorphic locus. The expected heterozygosity (HE) ranged at a moderate level from 0.4385 to 0.7163 in this population. Compared to that in the American alligators, a lower level of microsatellite diversity existed in the Changxing population as revealed by about 46% fewer alleles per locus and smallerHEat the homologous loci. The average exclusion power and the ability to detect shared genotypes and multiple paternity were evaluated for those markers. Results suggested that when the polymorphic loci were combined, they could be sensitive markers in genetic diversity study and relatedness inference within the Chinese alligator populations. The level of genetic diversity present in the current Changxing population indicated an important resource to complement reintroductions based on the individuals from the other population. In addition, the microsatellite markers and their associated diversity characterized in this population could be utilized to further investigate the genetic status of this species.