A Study On The Techniques For Subspecies Identification Of Tiger

Subspecies identification is an important issue in the phylogeny, taxonomy and conservation genetics of tiger. There has been evidence for subspecies discrimination from morphology, geography, isozyme polymorphisms etc, but no method was reported to accurately identify subspecies in question. We carried out a series of studies for such inssue based on fragment length polymorphis of microsatellite locus Ple46, sequence of NADH gene on mtDNA and subspecies specific alleles at 11 microsatellites. We found that microsatellite Ple46 was effective to discriminate species in leopard cat, tiger, mountain lion and leopard, but not able to discriminate leopard cat and domestic cat. In the group of big cats, namely lynx, clouded leopard, snow leopard, leopard and jaguar, this locus was also unable to discriminate. A similar unability was observed in the discrimination of tiger subspecies. Three tiger subspecies specific PCR primer pairs, named as Am-1/Am-2, Al-1/Al-2and Ti-1/Ti-2, were designed in the region of NADH gene of mtDNA to identify the south China tiger, Siberian tiger and Bengal tiger. These three subspecies was characterized by PCR products of 422bp, 405 bp and 145bp respectively. The test using multiple tiger subspecies and other species indicated that the primer pairs transfer the identification of subspecies to a discrimination of 0/1, and reliable to assign the subspecies origin of a given tiger. Based on the population analysis of 11 microsatellite loci namely Fca304, Fcal07, F146, Fca043, Fca391, Fca066, F42, Fca077, Fca074, Fca441 and F41 in the south China tiger, Siberian tiger and Bengal tiger, we totally found 16 south China tiger specific alleles, 5 Siberian tiger specific allele, 6 Bengal tiger specific alleles. A discrimination analysis using the 11 microsatellites as discriminating factors achieved 96.2% correct rate. The correct rate in the Siberian tiger and south China tiger hit 100%. Therefore, these subspecies specific alleles at the 11 microsatellite loci made up of a powerful tool to identify these three subspecies.