Journal of Biotechnology & Biomaterials
Open Access

Abstract

Tibetan sheep is distributed in Sikkim and Arunachal Pradesh. However, their population has been decreasing drastically in recent past. In Sikkim state these are confined to north district of Sikkim and at present are only 215 in number. Tibetan sheep have adapted themselves in the harsh climate and difficult terrains in their home tracts and may possess unrecognized beneficial genetic variation. These are an important reservoir of non-exploited genetic resources. Hence, the aim of the present study was to estimate the genetic intra-breed variability of Tibetan sheep using 25 microsatellite markers so as to provide useful information for their conservation. All microsatellites were polymorphic and a total of 148 alleles were detected across these loci. The observed number of alleles across all the loci was more than the effective number of alleles and ranged from 3 (BM6506) to 11 (BM6526) with 5.920�±0.387 mean number of alleles per locus. The average observed heterozygosity was less than expected heterozygosity. The observed and expected heterozygosity values ranged from 0.150 (BM1314) to 0.9 (OarCP20) with an overall mean of 0.473�±0.044 and 0.329 (BM8125) to 0.885 (BM6526) with an overall mean 0.672�±0.030 respectively. The lower heterozygosity pointed towards slower genetic diversity in the population. Four microsatellites (CSRD247, BM1314, OarJMP08 and BM6526) showed significant (p<0.05) departures from the Hardy-Weinberg proportions in the population. The estimate of heterozygote deficiency varied from -0.443 (OarCP20) to 0.668 (OarFCB128) with a mean positive valves of 0.302�±0.057. More than 30% deficiency of heterozygotes exists in population which can mainly be attributed to the inbreeding due to very small population size. Thus, the genetic analysis based on selected microsatellite markers indicated reduced genetic variability of Tibetan population. In view of the declining population of Tibetan sheep in the breeding tract, need of the hour is immediate scientific management of the population so as to increase the population hand in hand with retaining the founder alleles to the maximum possible extent.

Biography

Rekha Sharma has completed her PhD from National Dairy Research Institute (Deemed University), India in 1998. She is the Principal Scientist at NBAGR, a premier organization involved in characterization, conservation and utilization of animal genetic resources. She has published more than 55 papers in reputed journals on molecular characterization of AnGR with neutral and functional markers.

Email: rekvik@gmail.com