Shankaranarayanan P, Banerjee M, Kacker R K, Aggarwal R K, Singh L
Center for Cellular and Molecular Biology, Hyderabad, India.
Electrophoresis. 1997 Aug;18(9):1693-700. doi: 10.1002/elps.1150180938.
Previous reports have suggested that Asiatic lions and tigers are highly inbred and exhibit very low levels of genetic variation. Our analyses on these species have shown much higher degrees of polymorphism than reported. Randomly amplified polymorphic DNA (RAPD) analysis of 38 Asiatic lions, which exist as a single population in the Gir Forest Sanctuary in India, shows an average heterozygosity of 25.82% with four primers. Sperm motility studies by our colleagues corroborate this data. In Indian tigers, microsatellite analysis of five CA repeat loci and multilocus fingerprinting using Bkm 2(8) probe on a population of 22 individuals revealed a heterozygosity of 22.65%. Microsatellite analysis of loci Fca 77 and Fca 126 revealed polymorphism amongst the Asiatic x African lion hybrids, which has enabled us to use these as markers to discriminate the pure Asiatic lions from the hybrids. A similar analysis was used to identify hybrids of Indian and Siberian tigers through polymerase chain reaction (PCR) amplification of hair samples. To ascertain the variation which existed before the population bottleneck at the turn of the present century, microsatellite analysis was performed on 50- to 125-year-old skin samples from museum specimens. Our results show similar levels of genetic variability as in the present population (21.01%). This suggests that low genetic variability may be the characteristic feature of these species and not the result of intensive inbreeding. DNA fingerprinting studies of Asiatic lions and tigers have helped in identifying individuals with high genetic variability which can be used for conservation breeding programs.
先前的报告表明，亚洲狮和老虎高度近亲繁殖，遗传变异水平极低。我们对这些物种的分析显示，其多态性程度比报告的要高得多。对印度吉尔森林保护区中作为单一群体存在的38只亚洲狮进行随机扩增多态性DNA（RAPD）分析，使用四种引物显示平均杂合度为25.82%。我们同事进行的精子活力研究证实了这一数据。在印度老虎中，对22只个体群体的五个CA重复位点进行微卫星分析，并使用Bkm 2(8)探针进行多位点指纹分析，结果显示杂合度为22.65%。对位点Fca 77和Fca 126的微卫星分析揭示了亚洲狮与非洲狮杂交种之间的多态性，这使我们能够将这些作为标记来区分纯种亚洲狮和杂交种。通过对毛发样本进行聚合酶链反应（PCR）扩增，采用类似分析来鉴定印度虎和西伯利亚虎的杂交种。为了确定在本世纪初种群瓶颈之前存在的变异，对博物馆标本中50至125年历史的皮肤样本进行了微卫星分析。我们的结果显示，其遗传变异性水平与当前种群相似（21.01%）。这表明低遗传变异性可能是这些物种的特征，而非密集近亲繁殖的结果。亚洲狮和老虎的DNA指纹分析有助于识别具有高遗传变异性的个体，可用于保护育种计划。
