Genetic and demographic bottleneck analysis of Indian camel breeds by microsatellite markers.

Abstract

The genetic and demographic bottleneck analysis of Indian camel breeds was carried out utilizing 40 microsatellite markers. Allelic polymorphism was observed at 20 loci in the Indian dromedary breeds. A total of 66 alleles were scored. The average number of alleles, expected heterozygosity and polymorphic information content were, respectively, 3.25 ± 0.27, 0.56 ± 0.04 and 0.49 ± 0.04 in Bikaneri; 3.25 ± 0.25, 0.53 ± 0.03 and 0.46 ± 0.03 in Jaisalmeri; 3.0 ± 0.21, 0.53 ± 0.04 and 0.45 ± 0.03 in Kachchhi and 3.1 ± 0.19, 0.51 ± 0.03 and 0.44 ± 0.03 in Mewari breed. Higher genetic variation was observed in most numerous Bikaneri breed. Genetic distances were least between the breed pair Bikaneri and Jaisalmeri which was closely placed with the Kachchhi breed. The Mewari camels had relatively higher genetic distance from the other three Indian dromedary breeds. The bottleneck analysis revealed the presence of genetic bottleneck in all four breeds of Indian dromedary. However, the qualitative graphical method resulted in normal L-shaped distribution of allele frequencies in Jaisalmeri breeds and shifted mode in Bikaneri, Kachchhi and Mewari breeds. The demographic bottleneck analysis revealed minimum reduction (-9.65 %) in the population of camels in Jaisalmeri breeding tract as compared to that of Bikaneri (-14.18 %), Kachchhi (-27.78 %) and Mewari (-32 %) breeding tracts. Conclusively, the genetic bottleneck analysis could explain the demographic bottleneck in the Indian dromedary populations. Therefore, appropriate conservation and improvement efforts are needed in all four dromedary breeds with immediate attention on Mewari and Kachchhi breeds. The present study is the first report in demonstrating the genetic basis of demographic bottleneck in the Indian dromedary populations.