Study On Random Amplified Polymorphism DNA (RAPD) Of Goat (Sheep) Breeds In Sichuan Province

In this study, random amplified polymorphic DNA (RAPD) analysis was used to detect the phylogenetic relationship of 5 goat (sheep) breeds and four different groups of Black sheep in Sichuan, as well as genetic differentiation between billy goat (sheep) and nanny goat (sheep) in every breed.DNA of these goat (sheep) breeds, including Black goat, Nanjiang Brown goat, Beichuan white goat, Chengdu Ma goat and Xizang sheep were amplified with 30 random primers selected from 80 primers which have been used in RAPD analysis for goats and sheep. The individuals of 240 Black goats coming from four countries of Sichuan province, such as Hejiang, Huili, Yingshan and Jiang'an, 17 Beichuan White goats and 13 Nanjiang Brown goats were selected for further amplification. Experimental conditions for RAPD system of goat were explored and improved. Genetic distance indexes among breeds were calculated by Nei, the phylogenetic tree was constructed by UPGMA method, and genetic diversity between different groups was analyzed by Shannon index. The results show:1. Constructing gene pool and amplifying individual samples are both effective methods for showing the genetic differentiation between goat breeds. Thus, RAPD can be a useful marker for the analysis of genetic relationship among goatbreeds.2. The genetic distance between Nanjiang Brown goat and Chengdu Ma goat is the biggest (0.1348), therefore Black goat is far related to Nanjiang Brown goat. And the genetic distance between Black goat and Nanjiang Brown goat is the smallest (0.0621), therefore Black goat is closely related to Nanjiang Brown goat. While the genetic distance between Xizang sheep and any other goat breeds are all big, so Xizang sheep is far related to any other goat breeds.3. There is genetic differentiation between billy goat (sheep) and nanny goat (sheep) in every breed, which is far more apparent in Black goat.4. There is more plentiful genetic diversity between different group of Black goat while relatively rare diversity within the group, and there is more plentiful genetic diversity in billy goat groups of every Biack goat breeds than in namiy goat groups. The genetic Similarity coefficients between Hejiang Black goat and Jiang'an black goat is the biggest, while the genetic distance of Huili Black goat is far from the other three kinds of black goat.5. Phylogenetic relationship between the goat (sheep) breeds or within the groups of Black goat is in a large extent related with geographical distribution and the chance for gene commutation.