Abstract
Kappa casein plays a crucial role in the formation of stable casein micelles and has a key influence on milk-clotting properties. However, current understanding of buffalo CSN3 gene polymorphisms is not sufficient. In this study, the polymorphisms in the complete coding sequence (CDS) of the buffalo CSN3 were detected using PCR product direct sequencing. The CDS of CSN3 for river and swamp buffalo was the same in length, which contained an open reading frame of 573 nucleotides encoding a peptide containing 190 amino acid residues. A total of eight single nucleotide polymorphisms (SNPs) was identified in two types of buffalo. Among them, c.86C>T, c.252G>C, c.445G>A, c.467C>T and c.516A>C were non-synonymous, which leads to p.Pro8Leu, p.Lys63Asn, p.Val128Ile, p.Thr135Ile and p.Glu151Asp substitutions in buffalo kappa casein (-CN), respectively. The substitution of p.Thr135Ile may exert a vital effect on the function of buffalo -CN. Eleven haplotypes were defined based on the SNPs found in buffalo, and accordingly, seven protein variants and four synonymous variants of buffalo -CN were inferred, called variants A, B, B, C, C, C, D, E, F, F and G. The variants observed in water buffalo did not exist in the Bos genus. In addition, 14 amino acid differential sites of -CN between buffalo and the Bos genus were identified, of which 3 were located at glycosylation sites (80S, 96T, 141S) and 4 at phosphorylation sites (19S, 80S, 96T, 141S). It is speculated that they may lead to differences in the physicochemical properties of -CN between buffalo and the Bos genus. This study will lay a foundation for exploring the association between the variation in the CSN3 gene and the lactation traits of buffalo.
Highlights
Kappa casein (CSN3, κ-CN), as one of the main components of milk protein in mammals, plays an important role on casein micelle stability (Komori et al, 2013). κ-CN is situated predominantly on the surface of casein micelle in milk
The results showed that the coding sequence (CDS) length and the structure of the buffalo CSN3 gene were the same as those of the species in the Bos genus
The 5 -untranslated regions (UTRs) consisted of 69 nucleotides, and 3’-UTR was composed of 206 nucleotides
Summary
Kappa casein (CSN3, κ-CN), as one of the main components of milk protein in mammals, plays an important role on casein micelle stability (Komori et al, 2013). κ-CN is situated predominantly on the surface of casein micelle in milk. Κ-CN is situated predominantly on the surface of casein micelle in milk. As a result, destabilized casein micelles precipitate in the form of a gel (Hobor et al, 2008). This is a crucial process in milk coagulation for cheese making and for the nutrition of suckling calves (Caroli et al, 2009). Κ-CN is the only glycosylated casein for eutherians, which contains the sulfur amino acids cysteine and methionine.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
