Characterization of casein variants in the Guaymi and Guabala breeds through a low-density chip arrangement

Abstract

Studies of the genetic diversity of the Guaymi and Guabala cattle breeds have shown the need to evaluate various components, including the polymorphism of casein genes. The objective of this work is to characterize the casein variants in the Guaymi and Guabala landraces by means of a low-density SNP arrangement. Twenty-four SNP markers were typed in samples of Guabala and Guaymi Creole cattle. The values of Ho, He, and Fis, considering only the polymorphic loci in the Guabala breed, were 0.438, 0.449, and 0.011, respectively. In the case of the Guaymi breed, Ho, He, and Fis at the polymorphic loci were 0.513, 0.405, and −0.281, respectively. The effective number of alleles obtained from the Guabala breed was 1.167, and that in Guaymi was 1.257. This study determined the genetic diversity of the casein group in the Guaymi and Guabala breeds; however, few polymorphic alleles were observed, particularly in the Guabala race. Both breeds had high frequencies of the A2A2 genotype at rs43703011 (CSN2), which is considered favourable for production of quality milk. The identified markers will allow the design of strategies to reduce the levels of inbreeding and better understand the aptitudes of both breeds in terms of productivity.

Keywords

• Livestock
• local breeds
• molecular genetics
• biodiversity
• biotechnology