Caracterização genética da região promotora do gene do receptor de FSH em éguas da raça quarto de milha.

Abstract

The Quarter Horse is a breed that stands out for strength, explosion and versatility, being used in various equestrian sports, where drum and vaquejada competitions stand out. The search for genetically superior animals and the possibility of using individuals with acquired subfertility boosted the development of some reproductive techniques in horses. From ET, several biotechnologies emerged, breaking the barrier of subfertility and acquired infertility. Follicle stimulating hormone (FSH), a glycoprotein secreted by the anterior pituitary, can regulate ovarian function through the FSH receptor (FSHR), which regulates the functioning of FSH, in which it plays a central role in reproduction. Molecular biology techniques such as DNA extraction, PCR and DNA sequencing were established, as well as bioinformatics analyzes to identify new polymorphisms and future statistical analyzes associating polymorphisms with reproductive traits in mares with the aim of identifying genetic polymorphisms in the promoter region of the FSHR gene and to associate such polymorphisms with reproductive traits in embryo donor mares. Therefore, the aim of this work was to characterize part of the promoter region and the 5'untranslated region (5ÙTR) of the FSHR gene in quarter horses. Peripheral blood was collected from 81 mares from three farms for DNA extraction, followed by amplification of 707 bp of the promoter region of the FSHR gene. Then the PCR products were purified and sequenced by the Sanger method. The sequences were line up and compared between mares. Allelic, genotypic frequencies and inbreeding coefficients were determined by the Analytically, three polymorphisms (SNPs) were identified, two in the promoter region (-217G>T and -195G>A). In SNP-217, the most frequent allele and genotype are G=0.939 and GG=0.902. In SNP -195, the most frequent allele and genotype are G=0.896 and GG=0.841. One SNP was identified in 5-ÙTR at position 127A>G, with the most frequent allele and genotype being G=0.729 and GG=0.602. Binding disequilibrium was significant between SNPs -217 and -195. 74 segments with potential binding sites were identified in the wild-type sequence, being at position -217 the Sp1 and TFAP-2 alpha and at position 195 the site for GR, which, while in the sequence, 71 segments were identified, as the missing binding sites. The regulatory region of the FSHR gene presents variations considered polymorphic for population selections that may be involved in the assistance processes for molecular markers for relevant traits in reproductive factors.