Variation in lactoferrin gene affects milk lactoferrin content and somatic cell count in murrah buffaloes

Abstract

Lactoferrin plays an important role in antimicrobial defence and is a potential candidate gene for mastitis resistance. In the present investigation, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) studies were carried out in Murrah (Bubalus bubalis) buffaloes to detect single nucleotide polymorphisms (SNPs) of lactoferrin gene and to analyse the association between the observed polymorphisms with milk lactoferrin content and Somatic cell count (SCC). PCR-SSCP analysis revealed a total of 07 different variants in the partial coding region of the lactoferrin gene. PCR-SSCP analysis of exon 10 of lactoferrin gene revealed three and that of exons 4 and 5 revealed two unique patterns each, while all other exons exhibited monomorphic pattern. Comparison of nucleotide sequences of lactoferrin gene of the Murrah buffaloes with taurine reference sequence revealed a total of 14 point mutations, 09 of which were found to be in coding region. Conceptualized translation of nucleotide sequence revealed 07 amino acid changes. SSCP variants of exon 10 (P less than 0.01) had significant effect on milk SCC. The SSCP variants of exon 4 and exon 5 had significant (P less than 0.05) effect on lactoferrin content. The SCC and lactoferrin content in Murrah buffaloes was highest in 4th and above parity group. Stage of lactation had highly significant (P less than 0.01) effect on both milk SCC and lactoferrin content. There was a high and significant (p less than 0.01) correlation (0.741) between SCC and lactoferrin content in milk. The observed association between SSCP variants in lactoferrin gene with milk SCC and milk lactoferrin content can be used as prognostic markers for selection of animals for high lactoferrin content and low somatic cell count, as well as a marker of susceptibility/resistance to mastitis in Murrah buffaloes