Abstract:
The identification of SNPs as selection markers in candidate genes affecting milkyield and composition is of significance in MAS program. Milk fat and protein is variable constituent of milk and found associated with some SNPs. The objectives of the current study were to analyze the sequence polymorphism in the Kappa casein gene and examine the association of these polymorphisms to milk traits in Azikheli buffalo. Milk yield and composition data were collected from the Azikheli buffaloes herds raised under sedentary farming system at the Livestock and Diary Development Department (L&DD) KP Dairy Farm at Charbagh, Swat. The collected Azikheli samples (six) were categorized grossly in two groups based on their milk yield at peak lactation i.e., three buffaloes from high yielding and three from low yielding. Milk samples were analyzed for milk protein and fat contents. Genomic DNA was isolated from blood samples. The targeted region of Kappa casein gene including exon 3 and adjacent introns (969bp) was amplified through PCR using pre-designed primers. The purified PCR products were sequenced by Sanger sequencing at Beijing Genomic Institute. Milk Yield of high yielding category was 13.6 ±0.33 litres/day, and that of low yielding animals was 8.3 ± 0.33 liters/day. Fat content was also high (7.1 ± 0.37%) in high yielding animals compared to the low yielding buffaloes. Protein percentage was similar among both categories. The Sanger sequencing results revealed, a total of 42 variations in both high and low yield categories of Azikheli buffalo. In exon 3, a single variant was observed in high yielding animals at a frequency of 0.333. In low yielding animals, intron 2 and 3 possessed four and three different variants, respectively, while exon 3 showed no variants. Different in-silico tools were used for analysis of non-synonymous mutation identified in exon 3. According to the Swiss model and TM align tools the missense mutation involved in the amino acid change (Asparagine 25 Serine) yielded in no predicted change in the structure of Kappa casein protein. Six SNPs (SNP7942_7943insA, SNP7943, SNP7944, SNP7945, SNP8197 and SNP8550) in intron 2 showed positive correlation with milk yield. Similarly, four SNPs (SNP7939, SNP7940, SNP7946 and SNP7960) identified in intron-2 showed correlation with fat content. These results suggest that variations identified in the Kappa casein gene may have significant effect on milk yield and fat content. The missense mutation (g.8572A>G: Asn25Ser) can be used as potential marker for selection in Azikheli buffalo for breeding in future.
Page(s):
58-58
DOI:
DOI not available
Published:
Journal: Abstract Book on International Conference on Sustainable Agriculture and Food Security, August 27-31, 2023 , Volume: 0, Issue: 0, Year: 2023