Authors : S.L. Yang, B. Surintorn, N.L. Pongchan, N.N. Uthairat and Z.H. Shi
Abstract: To understand molecular genetic characteristics of Thai indigenous pig populations, researchers compared the genetic variation at 12 microsatellite loci and the mitochondrial DNA Cyt b gene in two populations of Thai indigenous pigs including Northeast Thai (NT) and South Thai (ST) pigs, a Wild Boar (WB) population and a Chinese Qianbei Black (CQB) pig population from Guizhou province of China. The higher effective number of alleles were detected in NT (7.09) and ST (6.3) pig compared to CQB (5.97) and WB (5.19) pigs. NT pigs had the highest PIC value (0.82) among all populations. The average expected Heterozygosity (HE) was 0.72 in NT and 0.71 in ST and 0.69 in WB pigs which was lower than that observed in CQB pigs (0.82). Hardy-Winberg (HWE) test showed of all 12 microsatellite loci, 7 loci were deviated from HWE (p<0.05). Seventy four polymorphism sites were detected among 35 Cyt b gene sequences of 1046 bp in four populations. Eighteen Cyt b haplotypes were detected and haplotype H9 was found in CQB, NT and ST pigs. Both the FST and Nei ’s standard genetic Distances (Ds) from the microsatellite data indicated genetic differentiation between Thai pigs and Chinese Southwest pigs but UPGMA tree showed that Thai pigs had close relationship with Chinese pigs. Structure analysis indicated that NT populations were identified as the separate clusters while few ST individuals was assigned into the CQB population at K = 2. Median-joining network analysis showed that the NT population constituted predominated haplogroups (54.28%). These results suggest that Thai indigenous populations have high genetic diversity in both nuclear and mtDNA data. The close relationship between Chinese Southwest pigs and Thai pigs implies that Thai native pigs might have the same origin as pigs from South or Southwest China. These findings can be used as valuable genetic information for the preservation and further genetic improvement of the Thai indigenous pig population.
S.L. Yang, B. Surintorn, N.L. Pongchan, N.N. Uthairat and Z.H. Shi, 2012. Genetic Variation and Population Structure of Thai Indigenous Pig Populations Based on Mitochondrial and Microsatellite DNA Markers. Journal of Animal and Veterinary Advances, 11: 509-516.