Genetic Diversity Study With Microsatellite DNA On 7 Native Sheep Breeds In China

The genetic diversity of 7 native sheep breeds in China was analyzed with the microsatellite marker technology based on the requirement of project assignment. The sheep breeds were as followings:Hu sheep,Hasake sheep,Bayinbuluke sheep,Aleitai sheep, Heizang sheep,Baizang sheep and Jin sheep. The thesis discussed the genetic variation within population and among populations. The results were followed: 1. The 286 alleles were tested in 28 microsatellite loci, and each locus had 10.6. The most was 18 in AGLA269, the second was 15 in BM4311. The least was 4 in BM315 and ILSTS021.2. The results showed that 28 loci had the highly dominant alleles and 11 loci had private alleles.3. The mean heterozygosity of different locus varied from 0.0629 to 0.5903, and of different population was from 0.3421 to 0.4215, which belonged to middle heterozygosity locus and population. The PIC value were less than 0.5 in BM315,ILSTS021, the other 26 loci were high diversity. In 26 loci, there were 4 loci which PIC value varied from 0.60 to 0.70, 13 loci which PIC value was from 0.70 to 0.80, and the other 9 loci's PIC value varied from 0.80 to 0.90. The PIC value in AGLA269 locus was the highest and in ILSTS021 locus was the smallest, which values were 0.8712 and 0.3453 each. The most value was 0.7590 in Hu sheep and the least was 0.7317 in Hasake sheep. 4. The Hu sheep had the most effective number of allele, which was 5.5309. The average effective number of allele in 19 loci was all more than 4.5. Almost all of the loci were not in the HDW equilibrium through the test of HDW with x2 in 7 sheep breeds, except BMC1206 locus in the Jinzhong sheep and ILSTS021 locus in the Hasake sheep.6. The Neutrality Test showed that 5 loci (MB009, BM1341, BM3033, BMS6444, BM315) belonged to neutrality locus.7. There was the major gene flow between Buyinbuluke sheep and Aleitai sheep (the value was 7.5731), and the relative least was between Heizang sheep and Hu sheep (the value was 3.0964).8. The F-statistic analysis indicated that the FST of different locus varied from 0.0293 (in BMS875) to 0.3969 (in ILSTS021), the average was 0.0747. The Nm was from 0.3799 (in ILSTS021) to 8.2854 (in BMS875), and the mean value was 3.0964.9. Adopted the method of UPGMA and NJ with the D coa genetic distance in the 7 sheep breeds, the dendrograms were drawed: Hu sheep and Hasake sheep, Bayinbuluke sheep and Aleitai sheep were in the close relationship each other. The cluster of other three breeds was complex.