Population Genetic Study On Small Captive Population Of Amur Tigers(Panthera Tigris Altica)

Great concerns recently had been put on small population, especially small captive population, not only because of its similarity with the real one but also it could be an appreciate model to disclose genetic rules during future evolution of population genetic structure. This would have profound implications, both theoretical and practical, for the fields as evolution, animal conservation, population genetics and animal breeding. One small captive population of Amur tigers (Panthera tigris altica), which had 14-year captive history since its foundation in 1986, was selected for such population genetic researches in this paper, which contained three experimental parts as:(1) DNA extraction from shed hairs. Three methods, which were Chelex, ionic detergent and non-ionic detergent, were respectively used to digest the shed hairs of one Amur tiger. Through followed amplification with RAPD primer and measurement by UV spectrophotometer, the results showed that DNA enough for followed Polymerase Chain Reaction (PCR) were gained with above three methods, meanwhile the Chelex methods would be the best choice among them by detail comparison.(2) Demographic data and its population genetic analysis. Based on demographic data of the whole population from 1986 to 1999 and pedigree data of one sampling population composed by 62 individuals, effective population size (A'e), heterozygosity percentile (//t/M)), fixation index (F), partial inbreeding coefficient, kinship coefficient, founder genetic contribution were calculated. Meanwhile, Gene Drop analysis and Population Viability Analysis (PVA) were conducted. The risk curve was estimated and the value of Minimum Viability Population (MVP) for this population showed that 230 at 99% (Effective population size vs. Probability of survival ), 217 at 95% and 170 at 50% during 1000-year period. Also several practical measurements were posed for the future development of this captive population.(3) Researches on genetic variation of captive population. Based on genetic markers such as Random Amplification Polymorphism DNA (RAPD) and Inter-Simple Sequence Repeats (ISSR), Gene diversity, Linkage Disequilibrium (LD), Mismatch Distribution, neutral test were estimated for the sampling founder population and the sampling offspring population respectively. The results showed that Gene diversity was similar in both populations but a little less in the offspring population which now have more individuals than founder population. Also the results disclosed that random genetic drift (87.3%) was the main cause of LD preserved in this captive population, compared with hitchhiking epistasis (12.7%).