Desenvolvimento de uma genotipagem biomarcadora de produtividade em rebanhos de bovinos leiteiros no Ceará

Abstract

With the growing knowledge of the genetic characteristics of farm animals, there has been an increase in interest in genetic strategies that use molecular markers to analyze characteristics of economic interest to the industry. The kappa-casein gene is related to characteristics such as milk production, protein and fat content, and coagulation of casein micelles, and is therefore a molecular marker of interest to the cheese and dairy industry. Currently, although there are already several genotyping tests for other molecular markers related to milk, such as the β-casein gene, the market for molecular genotyping tests for the κ-casein gene is still not widely exploredin Ceará. In view of this, the present study, carried out in partnership with the company TaqMol Diagnósticos, sought to develop a molecular test based on genotyping techniques by real-time quantitative PCR (qPCR) to allow better management of dairy cattle herds and the selection of individuals with economically desirable productive characteristics. To this end, a real-time PCR protocol was developed to optimize the reaction and cycling parameters. The samples used were obtained through the company TaqMol Diagnósticos and had gDNA extracted from a commercial kit. Specific primers and hydrolysis probes owned by the company were designed and tested to amplify the κ-casein gene. The PCR product was cloned into the pGEM®-T Vector cloning vector to obtain a positive control. Sanger sequencing of the cloned gene from the transformed colonies indicated AA homozygosity for the cloned sample. The qPCR test developed, given its specificity and sensitivity due to the use of specific hydrolysis probes for the identification of SNPs of the CSN3 gene, presents strong evidence of being a viable and reliable technique for κ-casein genotyping.