The brown type donkeys of Andhra Pradesh, which are mainly concentrated in Kurnool and Anathapur districts, were evaluated for within breed genetic diversity and bottlenecks using heterologous microsatellite markers. The genomic DNA, isolated from 28 blood samples collected from Kurnool district, were amplified by PCR using FAM and HEX labeled primers and resolved for alleles on automatic DNA sequencer. In all, twenty loci of the horse origin were tested and only 12 loci gave scorable results. Rest of the loci either did not amplify (HMS3 and HMS7) or did not resolve properly (VHL20) or showed less than 4 alleles (HMS5, HMS6, HTG4, ASB17 and COR22) in the studied population. At the 12 loci included in the final analysis, the PCR product size range varied from 76-92 bp at locus HTG6 to 257-273 bp at locus COR18. The observed number of alleles varied from 4 (VHL209) to 10 (AHT5 and HTG7) with a mean of 6.92±1.83. The effective number of alleles ranged from 1.62 (VHL209) to 7.91 (AHT5) with a mean of 4.21±2.06. The observed heterozygosity ranged from 0.32 (HMS2) to 0.92 (AHT5) with a mean of 0.57±0.2. The expected heterozygosity ranged between 0.39 (VHL209) to 0.89 (AHT5 and HTG7) with a mean of 0.72±0.14. The mean genetic diversity estimate (FIS) was 0.21 indicating moderately high levels of inbreeding. The cumulative exclusion probability (PE) of these loci was 0.999892 indicating their suitability for parentage testing in these donkeys. The sign test, standardized differences test, the Wilcoxon test using the allelic frequency data at the studied loci as well as normal 'L' shaped distribution of the allelic frequency indicated the absence of any recent genetic bottleneck in Brown type donkeys of Andhra Pradesh. When these donkeys were compared to Spiti donkeys of Himachal Pradesh on the basis of allelic frequency data at these loci, they showed Nei's standard and unbiased genetic distances of 0.32 and 0.29, respectively.
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