Vol. 6, Issue 8 (2017)

Author(s):
G Radhika, P Amareswari, ST Viroji Rao, S Sakaram and T Raghunandan

Abstract:

Aim: This work was conducted to study the polymorphism and also the inheritance pattern of the FecB gene in the NARI Suwarna sheep which were procured from Nimbkar Agricultural Research Institute, Phaltan, Maharashtra and are being maintained at Instructional Livestock Farm Complex, College of Veterinary Science, Rajendranagar, Hyderabad. Materials and Methods: DNA isolation and gene-specific amplification of FecB gene was performed from blood samples of 25 NARI Suwarna sheep. The amplicons were then subjected to PCR - RFLP and Nucleotide sequencing to identify different genotypes with respect to the target gene. Results: Out of 25 samples screened for FecB gene, four samples were homozygote (BB) with 108bp and 32bp, 15 samples were heterozygote (Bb) with 140bp, 108bp and 32bp and the remaining six samples were wild type (bb) with 140bp. The AvaII digestion of 140bp exon 8 yielded three genotypic patterns indicating only two allelic variants whereas the AvaII digestion of PCR product 198bp for exon 9 and 153bp for exon 10 did not produce any restricted fragments, indicating the absence of restriction site. The exon 8 showed three genotypes (BB, Bb and bb) in NARI Suwarna flock with genotypic frequencies as 0.16, 0.60 and 0.24 and the allelic frequencies were 0.46 and 0.54 for the alleles B and b, respectively. The results suggested that the polymorphism showed only in exon 8 region of FecB gene. Conclusion: The FecB gene was present in some of the animals studied and absent in others. Out of three segments of FecB gene (exon 8, 9 and exon 10) only exon 8 showed polymorphism and the remaining segments are thought to be non-polymorphic and conserved among the breeds. Further, study with larger sample size is needed to elucidate the existing polymorphism in this gene.