Genotyping of the kappa-casein and leptin genes in Cuban water buffalo by PCR-RFLP

Abstract

Genetic analysis of loci affecting production and reproduction traits in livestock animals make possible the evaluation of animal breeding values using molecular markers. The aim of this study was to detect polymorphisms in the leptin and k-casein genes of a Cuban water buffalo population to provide markers useful for associating studies. Genomic DNA from 68 unrelated Cuban buffaloes, uncontrolled crossbreds of river (Buffalypso) and swamp (Carabao) animals, was analyzed using PCR-RFLP. Fragments of leptin and ê-casein genes were amplified and digested with Bsa AI and Hind III/Taq I, respectively. All the amplified samples were monomorphic BB after digestion with Hind III/Taq I. Genotypic frequencies found in the leptin gene with Bsa AI were 0.47 (AA), 0.42 (AG) and 0.11 (GG). The population was in HWE (p=1.0000), possibly because there was not selection for this locus on it. The FIS estimate (0.0212) showed no inbreeding in the population regarding this locus. He (0.436) and Ho (0.426) values were below 0.5 (50%), indicating low genetic variation in this locus in the population. PCR-RFLP detected the two genetic variants described for the leptin gene A1620G. However, a higher number of animals and SNPs in the leptin and/or other genes should be analyzed for a more accurate estimate of the genetic diversity in this population. DNA sequencing should be assayed by nucleotide sequence analysis to detect the new A and B variants of k-casein reported in buffalo.

Key words: leptin, Casein, buffaloes, PCR-RFLP, genetic variants.