Parentage And Genetic Diversity Studies In Luokeng Chinese Crocodile (Shinisaurus Crocodilurus) Using Microsatellite DNA Markers

SummaryCrocodile lizard (Shinisaurus crocodilurus) commonly known as sleeping snake, the underdog, and the small cairica, is a primitive reptile species in the Quaternary glacial in south China. It is the first level protected species in China and was included in CITES Appendix Ⅱ in1989. Due to human hunting and habitat fragmentation effects, Shinisaurus crocodilurus are in endangered edge. In order to protect this species well, understand the genetic diversity of artificial crocodile lizards populations, improve the genetic management stratgies, we used molecular genetic markers to study the kinship of artificial crocodile lizards populations,In order to solve the sampling limitations in Shinisaurus crocodilurus molecular biology study, We used buccal swabbing to collect saliva samples from the mouth of S. crocodilurus DNA from mouth saliva samples and Tissue samples of S. crocodilurus were extracted by DNA extraction kits respectively and PCR amplificated. The results showed that the PCR amplification results of mouth saliva samples’DNA and those of tissue samples’DNA were almost same. The results indicate that the DNA collected from the mouth saliva of S. crocodilurus by buccal swabbing can be used for conservation genetic study of S. crocodilurus.Twelve microsatellite loci were used to study the genetic diversities of127crocodile lizards. Fifty-two alleles were detected in12microsatellite loci and the microsatellite alleles are between2-13. Among these alleles, the EX10locus had the highest sites, up to13sites, and the average number of alleles was5.17. The average heterozygosity of each locus microsatellite loci was0.5412, the average polymorphism of12loci was0.5398. The results demonstrated that the polymorphism of the12loci microsatellite was relatively high. These polymorphism can react the genetic diversity of crocodile lizard at the molecular level. By using the12loci, the probability of paternity exclusion was from0.5to0.963. The cumulative frequency of these12sites showed that no-parent exclusion rate was higher than99%and these12sites could be used to identify paternity relationship of crocodile lizard. Among16clutches of crocodile lizard in the Luokeng artificial populations,2clutches could not indentified the paternity. In14clutches, the overall observed incidence of multiple paternity was42.9%(6of14clutches)In order to protect this endangered species effectively, hierarchical relationship of the artificial population should be established. More measures should be made to avoid or reduce inbreeding and maintain genetic diversity of the population.