Caracterização da variabilidade de genes relacionados à fertilidade de machos e ao temperamento em eqüinos da raça brasileira Mangalarga

The aims of the present study were to propose a PCR-RFLP genotyping method for the AJ_315378:c.110A>G and AB_264325:c. 771G>C SNPs in the equine CRISP1 and HTR1A genes, respectively, as well as to characterize these and another polymorphism, AB_098561:c.1470G>A of the SLC6A4 gene, in order to provide a basis for future studies investigating the association between DNA markers and traits of interest in this breed. For this, 151 Mangalarga horses of both sexes, representatives of the population of the Sate of São Paulo, Brazil, were used. PCR-RFLP was found to be adequate for the genotyping of the SNPs AJ_315378: c.110A>G of the CRISP1 and AB_264325:c.771G>C of the HTR1A. However, the polymorphism of the CRISP1 probably does not occur in Mangalarga horses, a fact impairing association studies of this marker with traits related to male fertility. The estimative of the population genetic parameters obtained for the polymorphisms AB_264325:c.771G>C of the HTR1A and AB_098561:c.1470G> A of the SLC6A4 in the studied sample discourage the conduct of research addressed the association between markers and traits related to temperament.

Caracterização da variabilidade de genes relacionados ao desenvolvimento muscular, fertilidade e temperamento em equinos da raça mangalarga

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A polymorphism within the equine CRISP3 gene is associated with stallion fertility in Hanoverian warmblood horses

Fertility of stallions is of high economic importance, especially for large breeding organisations and studs. Breeding schemes with respect to fertility traits and selection of stallions at an early stage may be improved by including molecular genetic markers associated with traits. The genes coding for equine cysteine-rich secretory proteins (CRISPs) are promising candidate genes because previous studies have shown that CRISPs play a role in the fertilising ability of male animals. We have previously characterised the three equine CRISP genes and identified a non-synonymous polymorphism in the CRISP1 gene. In this study, we report one non-synonymous polymorphism in the CRISP2 gene and four non-synonymous polymorphisms in the CRISP3 gene. All six CRISP polymorphisms were genotyped in 107 Hanoverian breeding stallions. Insemination records of stallions were used to analyse the association between CRISP polymorphisms and fertility traits. Three statistical models were used to evaluate the influence of single mutations, genotypes and haplotypes of the polymorphisms. The CRISP3 AJ459965:c.+622G>A SNP leading to the amino acid substitution E208K was significantly associated with the fertility of stallions. Stallions heterozygous for the CRISP3 c.+622G>A SNP had lower fertility than homozygous stallions (P = 0.0234). The pregnancy rate per cycle in these stallions was estimated to be approximately 7% lower than in stallions homozygous at this position.