Polymorphism and molecular characteristics of the <i>CSN1S2</i> gene in river and swamp buffalo

Abstract

Abstract. The αS2-casein (αS2-CN) is a member of the casein family associated with milk traits in ruminants, but so far the buffalo CSN1S2 gene has not been well understood. In this work, the polymorphisms of CSN1S2 in river and swamp buffalo were detected using direct sequencing of polymerase chain reaction (PCR) products. As a result, 13 single nucleotide polymorphisms (SNPs) were identified in the coding sequence (CDS) of CSN1S2 in two types of buffalo, of which eight SNPs were non-synonymous. The amino acid changes caused by c.580T>C and c.642C>G may affect the function of buffalo αS2-CN. A total of 11 CSN1S2 CDS haplotypes were defined, and accordingly 11 variants of buffalo αS2-CN were inferred and named. The CSN1S2 CDSs of both types of buffalo were 669 nucleotides, which encoded a precursor of 222 amino acids (AAs), and the first 15 AAs constitute a signal peptide. The composition and physicochemical characteristics of two types of buffalo αS2-CNs were similar but slightly different from those of cattle αS2-CN. The αS2-CN mature peptides of buffalo and the species of Bos genus contained a casein domain, and their secondary structures were highly consistent, indicating that they are functionally similar. The results here provide initial insights into the variation, characteristics and biological function of buffalo CSN1S2.

Comparative Genomics, Evolutionary and Gene Regulatory Regions Analysis of Casein Gene Family in Bubalus bubalis

“…Comparative amino acid sequence analysis revealed that CN protein harbor higher amino acid variations in river buffalo (Mediterranean and Murrah) as compared to the swamp buffalo. The results of the present study are in line with previous studies (Masina et al, 2007;Azevedo et al, 2008;Massella et al, 2017;Rangel et al, 2017;Miluchova et al, 2018;Fan et al, 2020;de Oliveira et al, 2021) which reported the potential association of genetic variants in CSN genes with lactation performance, milk composition, and attributes of milk products. Thus, casein gene-based markers are important candidates for the selective breeding of buffalo to improve the quantity and quality of milk (de Oliveira et al, 2021).…”

“…Buffalo is a luxurious genetic resource with multiple utilities (as a dairy, draft, and meat animal) and economic significance in the tropical and subtropical regions of the globe ( Rehman et al, 2019 , 2020 ; Luo et al, 2020 ). The domesticated buffalo is grouped into river buffalo with karyotype 2n = 50 primarily present in southwestern Asia, India, south Mediterranean Europe, and Egypt and swamp buffalo with 2n = 48 distributed across Southeast Asia, southern and southeast China, where the swamp buffalo is used as draft power in the rice paddy fields while the river buffalo is mainly reared for milk production ( Moioli et al, 2001 ; Fan et al, 2020 ; Luo et al, 2020 ). The excellent potential to survive and perform on marginal resources under harsh environmental conditions makes buffalo an important source for nutritious products, particularly milk and meat.…”

“…The excellent potential to survive and perform on marginal resources under harsh environmental conditions makes buffalo an important source for nutritious products, particularly milk and meat. Buffalo contributes about 13% of global milk production where the river buffalo produces 2,000 kg milk per year and swamp buffalo annual production is 500–600 kg ( Basilicata et al, 2018 ; Fan et al, 2020 ; Lu et al, 2020 ). Moreover, the physio-chemical characteristics of buffalo milk are different from cow milk, and buffalo milk is relished due to its peculiar taste and higher butterfat content ( Li et al, 2020 ).…”

“…Casein (CN) is the major milk protein, contributing 80% of the whole milk proteins including α-s1-CN, α-s2-CN, β-CN, and k-CN. Each CN protein has its unique amino acid configuration, genetic and functional properties ( Fan et al, 2020 ). Milk CNs are physiologically important as they provide food to the newborn and are associated with milk processing properties and lactation behaviors of dairy animals ( Nilsen et al, 2009 ).…”

Whole-Genome Sequencing and Characterization of Buffalo Genetic Resources: Recent Advances and Future Challenges

“…In the CSN1S2 gene, the coding sequence of river and swamp buffaloes, 13 SNPs were identified, including 8 non-synonymous substitutions. The amino acid variations due to c.580T > C and c.642C > G might have a physiological impact on the αS2-CN synthesis and ultimately the milk yield in buffaloes [ 120 , 121 ].…”