Vataliya, P. H.PATEL, KETANKUMAR SHAMALBHAI2018-05-252018-05-252009http://krishikosh.egranth.ac.in/handle/1/5810047529Diacylglycerol-0- acyltransferasel (DGATI) is a microsomal enzyme that catalyzes the final step in triglyceride synthesis by using diacylglycerol and fatty acyl CoA as substrates. DGATI gene, located in the proximal region of chromosome 14 in cattle, has been identified as a strong candidate gene for the QTL for milk production traits. Single Nucleotide Polymorphism (SNP) variation in DGAT1 gene in association with milk yield and milk Fat % in buffaloes might be a useful tool to select the high producing animals at early stage of life. The present study was undertaken to screen Mehsana buffalo at three SNP positions (3057, 3627 and 8426) in DGATJ gene using PCR- RFLP and to correlate these SNPs with milk yield and milk Fat %. Genomic DNA was extracted from blood samples of 100 Mehsana buffalo females collected under a project "Parentage Verification of Progeny Test Daughters" in collaboration with DURDA, Dudhsagar Dairy, Mehsana, Gujarat. Of these 100 genomic DNA samples, 25 samples were from high milk producing animals (2213- 3010 liters/lactation), 25 from low milk producing (836- 1513 liters/lactation), 25 from high milk fat % (5.7- 6.4 %) and 25 from low milk fat % (7.7- 8.6 %) animals J Three PCR primer pairs viz., DGAT1-5 (F- 5' TTg gCA ggT TgT AgC ATg Ag 3' and R- 5' gCA Agg CCT CCA gTT TTg TA 3') specific to intron 1 which included nt position 3057, DGAT1-6 (F- 5' ggC CTC TCC CCT TAC AAA AC 3' and R- 5' CAC ACA CCA ATT CAg gAT gC 3') specific to part of intron 1 and exon 2 which included nt position 3627 and DGATl-\6 (F- 5' gAT AgT ggg CCg CTT CTT C and R- 5' TgC ACA gCA CTT TAT TgA CAC A 3') specific to exon 17-3' downstream which included nt position 8426, were used for amplification of specific DNA. Amplified products were visualized as a single compact band of expected size of 503 bp, 661 bp and 413 bp, respectively under UV light by gel documentation system. PCR products for screening SNP positions 3057, 3627 and 8426 were restriction digested by NmuCI, Smal and Ehel RE respectively. Presence of restriction site for NmuCI RE at SNP position 3057 was inferred as 'A' allele, otherwise as 'G' allele. For SNP positions 3627 and 8426, presence of restriction sites for Smal and Ehel RE, respectively were inferred as 'C allele, otherwise as 'T' allele. r Frequency of 'A' allele was predominant (0.96 for high milk producing, 0.94 for low milk producing, 0.96 for high fat % producing and 1.00 for low fat % producing groups) for SNP position 3057. Frequency of 'C allele was predominant (0.78 for high milk producing, 0.78 for low milk producing, 0.84 for high fat % producing and 0.82 for low fat % producing groups) for SNP position 3627. Frequency of 'T' allele was predominant (0.68 for high milk producing, 0.64 for low milk producing, 0.76 for high fat % producing and 0.52 for low fat % producing groups) for SNP position 8426. Results indicated that no particular variant with higher frequency was present in any specific group) There was no significant difference (P > 0.05) for any variant of these three SNPs with respect to milk yield and milk Fat %. Therefore, there were no significant associations of these three SNPs with milk yield and milk fat % in Mehsana buffaloes.enCHARACTERIZATIONThesis