Comparación de alelos de receptores para FSH y LH identificados mediante el ensayo PCR-RFLP en bovinos Holstein y Criollo de la provincia del Azuay

Abstract

Variability in reproductive genes, such as those that encode receptors for follicle-stimulating (FSHR) and luteinizing (LHR) hormones, has decreased in recent decades, both in specialized dairy cattle and in creole cattle. Curiously, in this last breed a high variability is suggested, important for genetic improvement and its conservation. The objective of the study was to contrast the frequency of the FSHR and LHR genes in the Holstein and Creole bovine populations of the Azuay province by means of an assay based on the polymerase chain reaction and the identification of restriction fragments of polymorphic length (PCR- RFLP) from DNA of both races. Three genotypes were identified: CC; CG and GG for FSHR, and only one (GG) for LHR, the entire population being homozygous for this locus. For FSHR, 56% of the individuals were CC homozygous, with a higher percentage of these in Holstein cattle (67%); while, in the Criollo cattle, 55% were heterozygous, being the C allele predominant in both breeds. Greater heterozygosity was observed for the FSHR locus, in Criollo cattle with observed heterozygosity (Ho) (0.5517) higher than expected (He) (0.3995); while Holstein cattle presented moderate heterozygosity; Furthermore, in both breeds there was no evidence of consanguinity. Both the genetic differentiation and the distances between these two races were small. The total population was found in genetic equilibrium for FSHR, these results allowed characterizing the study population as non-inbred, with the same allelic frequencies and with greater variability in the Creole race for this locus.