VINOO, R(MAJOR)MURALIDHAR, MVENKATA SESHAIAH, Ch.PRASANNA, BARATAM2019-07-162019-07-162019-04http://krishikosh.egranth.ac.in/handle/1/5810114858THESESIndia is bestowed with 43 recognized sheep breeds and several unrecognized genetic groups exists in different geographic locations which are yet to be documented and registered. So far Nellore is the only sheep breed that is recognized in Andhra Pradesh. Apart from this breed, other locally adopted genetic groups exist and one popular sheep among them is in north coastal region of Andhra Pradesh, called Vizianagaram sheep. The present study was carried out to establish breed characteristics of Vizianagaram sheep and also to assess the genetic diversity at molecular level using thirty microsatellite markers recommended by FAO for genetic diversity studies in sheep. A total of 451 sheep of different age groups were used to study the morphometric characters of Vizianagaram sheep and 56 blood samples from unrelated sheep were used for molecular studies. The predominant color of these animals is white with tan/brown/black color patches on nose line, lateral face, neck/mane, perineum, back and lower extremities. The ears in this genetic group of sheep are observed to be either pendulous or tubular. Few of the animals are with rudimentary ears. Prominent occipital bone, black patches around eyes, hair on thigh, dewlap and neck/mane region are the important features of this genetic group. The overall least squares means of body weights (kg), height at withers (cm), chest girth (cm) and body length (cm) were 22.10±0.76, 64.96±0.48, 68.67±0.64 and 62.30±0.42 at 2 teeth age, 26.03±0.75, 66.86±0.74, 72.33±0.78 and 65.13±0.55 at 4 teeth age, 28.89±1.21, 67.20±0.69, 74.75±1.07 and 65.76±0.81 at 6 teeth age and 28.09±0.62, 67.22±0.40, 76.76±0.51 and 65.89±0.37 at full mouth respectively. DNA isolated from 56 Vizianagaram and 40 Nellore Jodipi blood samples was utilized for microsatellite analysis. A total of 377 and 321 alleles were observed across 30 loci in Vizianagaram and Nellore Jodipi respectively. On an average about 11-12 alleles per locus were observed in both the genetic groups. Effective number of alleles range from 1.999 to 11.314 and 1.838 to 11.220 in Nellore Jodipi and Vizianagaram sheep respectively. The allele sizes ranged from 70bp (OARFCB20) to 293bp (ILSTS11) and 70bp to 283bp (ILSTS11) in Vizianagaram and Nellore Jodipi sheep, respectively. The mean observed and expected heterozygosity value was 0.685 and 0.757 in Vizianagaram population while it was 0.689 and 0.744 in Nellore Jodipi population. PIC of the markers ranged between 0.457 (OARCP38) and 0.861 (OARFCB304) in Vizianagaram sheep while it was 0.345 (MAF214) and 0.866 (ILSTS11) in Nellore Jodipi sheep. The mean FIS estimates among the two populations, were 0.084 for Nellore Jodipi and 0.086 for Vizianagaram sheep. The Pairwise Nei’s genetic distance and identity estimates were 1.6% and 98.5% respectively. The study concluded that Vizianagaram sheep were phenotypically distinct from other breeds with low genetic differentiation at molecular level.ennullThesis