Breed characteristics and genetic variability in Changthangi goats

Changthangi, a Pashmina yielding goat breed of India, is found at high altitudes ranging from 3000 to 6000 m above mean sea level in the trans Himalayan mountain range bordering Tibet. It is more localized in Changthang sub division of Ladakh region of Jammu and Kashmir. The study was done to know the genetic variability within breed. Genomic DNA isolated from randomly collected blood samples was amplified using standard PCR conditions before analyzing on an automatic DNA sequencer. A battery of 12 microsatellite markers was used for genetic characterization. The data thus generated were analysed to estimate the allele frequencies, allele number, heterozygosity, poly information content and inbreeding coefficient. The observed number of alleles varied from 5 (OarJMP 29) to 19 (Oar FCB304) with a mean of 10.4 ± 3.91. The effective number of alleles varied from 1.56 (OarJMP29) to 8.92 (OarFCB304) with a mean 4.59 ± 2.07. The value of Shannon information index (I) ranges from 0.774 ( OarJMP29) to 2.487( OarFCB304) whereas poly information contents range from 0.343 ( OarJMP29) to 0.846 ( OarFCB304). The high value of I and PIC indicated the suitability of markers for studying the genetic variability in goat species. Observed heterozygosity ranged from 0.2368 (OarJMP29) to 0.9783 (OarFCB304). The mean observed heterozygosity was 0.3979. The expected heterozygosity was highest (0.8880) for locus Oarfeb 304 and lowest (0.3618) for locus OarJMP29. Nine of the 12 loci showed the positive inbreeding coefficient. Among the positive values the Fis varied from 0.0527 ( ILSTS008) to 0.6491 ( OMHC1) with a mean of 0.1773 however, ILST044, ILSTS002, OarFCB304 exhibited the negative values corresponding to 0.0471, 0.0855 and 0.1016 respectively. The L shaped curve obtained indicated that Changthangi population has not undergone any recent bottleneck. The study indicated that Changthangi goats exhibited substantial amount of genetic variation as reflected from the heterozygosity and number of alleles per locus. Avoiding unplanned and indiscriminate mating between individuals can increase the heterozygosity which can be exploited in the improvement of productivity of this breed.