Resumo

C RINCON, Juan; LOPEZ, Albeiro  e  ECHEVERRI, Julián. Genetic variability of the bovine prolactin-Rsal loci in Holstein cattle in Antioquia province (Colombia). Rev Colom Cienc Pecua [online]. 2012, vol.25, n.2, pp.191-201. ISSN 0120-0690.

The Holstein breed, widely used in Antioquia's dairy industry, has undergone genetic changes due to selection that have affected the frequencies of some polimorphisms within important genes. Objective: to identify polymorphism changes in the prolactin RsaI (PRL-Rsal) locus and to characterize the structure and allelic distribution within the Holstein population in Antioquia. Methods: a total of 1.462 Holstein cows from 11 subpopulations (municipalities) of Antioquia were used. The ADN was extracted from leucocytes using the salting-out method and genotyping was performed by PCR-RFLP. Genetic diversity was determined by heterozygosity. The Hardy-Weinberg equilibrium (HW) and the genetic differentiation among populations were performed using the Arlequin 2.0 software. Allelic and genotypic frequencies were assessed with the SAS 9.2 statistical software. Results: the genotypic frequencies found were 0.695 (AA), 0.276 (AB), and 0.029 (BB), while the frequencies of the A and B alleles were 0.833 and 0.167, respectively. There were no deviations from HW equilibrium in any population. Genetic diversity among populations, expressed in terms of heterozygosity, showed a medium value (Ho=0.276). The F_ST value of the entire population was significant, indicating genetic differentiation. In addition, some matched F_ST showed high differentiation. The F_IT and F_IS parameters were not significant, suggesting that population endogamy or exogamy is not occurring. Conclusions: the bovine PRL-RsaI polymorphism is a suitable marker to evaluate characteristics of economic importance and apparently it has not been influenced by selection pressure. In fact, a significantly high variability (p<0.05) in allele frequencies was observed within the Antioquian Holstein cattle subpopulations.

Palavras-chave : genetic differentiation; Hardy-Weinberg equilibrium; PCR-RFLP; single nucleotide polymorphism.

        · resumo em Português | Espanhol     · texto em Espanhol     · Espanhol ( pdf )