Study On DNA Polymorphism In Artificially Reared Nipponia Nippon

Nipponia Nippon, as an endangered bird in the world, has been considered one of four natural treasures in China. There were only 7 Nipponia Nippon individuals discovered in 1981 in Yangxian, Shaanxi Province. Yangxian artificially reared Nipponia Nippon were developed by these 7 birds. It was well known that a scientific guidance in protecting endangered species by modern molecular biological methods became more and more inevitable. Study on polymorphism and genetic background of Nipponia Nippon from Yangxian, Shaanxi province, would help to prevent from the lose of genetic polymorphism and decline of biological fitness in offsprings. In this study, genetic polymorphisms of 43 Nipponia Nippon individuals from Yangxian were evaluated with mtDNA sequence analysis, microsatellite marker and RMAPD. The results were as follows:298 bp DNA fragment from mtDNA D-loop control region of 42 Nipponia Nippon individuals were sequenced and analyzed. Haplotypes were detected out. Individual numbers and percentage of four haplotypes were 9, 8, 2, 23 and 21.43%, 19.05%, 4.76% 54.76, respectively. Only two mutation loci (namely transversion) were found, which indicated a near maternal origin relationship between these birds. The results were identical with the fact that their ancestors come from seven wild Nipponia Nippon.303 bp DNA fragments of Cyt b gene sequence in mtDNA of five Nipponia Nippon individuals were analyzed and no mutation was found, which implied Cyt b gene were highly homological and genetic relationship of them was close. The results indicated the origin of Nipponia Nippon was comparative singleness.Homology of eighteen Cyt b gene sequences in mtDNA region among Threskiornithidae, Ciconiidae, Phoenicopteridae, Ardeidae and Gruidae were analyzed and their BSR and genetic distances calculated. Seventeen haplotypes were discoveried. Genetic distances between Nipponia Nippon and other species ranged from 0.0932 to 0.1665. The clustering result by Neighbour Joint clusterinhg method indicated Nipponia Nippon, Plegadis falcinellus and Platalea alba were firstly clustered together, which was identical with the results of morphological observation.Genomic DNA samples from 43 Nipponia Nippon individuals were amplified with 27 paires of microsatellite primers and polymorphism was found on 4 microsatellite loci, which demonstrated some microsatellite primers from other species, such as bovine and sheep, could be used in Nipponia Nippon genomic DNA analysis, but the universality was limited. Average locus heterozygosity, PIC, effective allelic numbers of four loci were 0.349, 0.304, 1.77, respectively, which indicated genetic polymorphism of Nipponia Nippon was poor. RMAPD was a novel molecular marker technique. It was more stable and polymorphic than RAPD. Hence RMAPD was considered better than microsatellite marker and RAPD in genetic polymorphism detection within population.Genetic polymorphism of 43 Nipponia Nippon individuals was analyzed with RMAPD marker. Results showed that BSR and genetic diversity indexes were 0.718, 3.664, respectively, which indicated genetic structure of the Nipponia Nippon was simple and poor genetic variations exists in the Nipponia Nippon group from Yangxian.