Prospecção e caracterização de SNP‟s relacionados à qualidade de carne ovina

Abstract

In this study, we sought to evaluate the polymorphism by means of analysis of point mutations (SNP) of seven genes related to muscle development to softness and lipid profile of sheep meat (calpastatin - CAST, myostatin - GDF8, Stearoyl CoA desaturase - SCD, field of thioesterase - TE, Fatty Acid Synthase - FASN and Diacylglycerol Acyltransferase - DGAT 1 and 2). We used 84 male sheep grouped in six genetic clusters obtained from a cross between the following races: Santa Ines × Santa Ines, Santa Inês × Dorper Black, White Dorper × Santa Inês, Santa Inês × Texel, Santa Inês × Lacaune, and Santa Inês × East Friesian. The experiment was established in completely randomized design (CRD) with six treatments corresponding to crossings with about 14 repetitions, each consisting of an animal. Analyzes were carried out seeking for polymorphisms, using the PCR-SSCP technique that showed results with different patterns in polyacrylamide gel. The sequencing of samples with the help of free software Sequence Scanner Software (Applied Biosystems) was used to identify polymorphisms. The SSCP technique detected a single standard band in DGAT-1 and SCD genes; two banding patterns in FASN gene in three patterns GDF-8 genes and TE four patterns in the CAST gene and DGAT-2. The CAST gene were identified four genotypes (AA, AB, BB and BC) and sequencing identified two polymorphisms (c.227A> G; c.383A> G) which resulted in the exchange of glutamic acid for glycine and threonine to alanine respectively. Since, for the GDF-8 gene were observed genotypes (DD, DE, FF) and sequencing revealed the presence of polymorphisms 4, which resulted in no exchange of amino acids. In DGAT-2 gene were identified four genotypes (MO, MP, NP and MQ) and sequencing resulted in the presence of two polymorphisms (c.229T> C; c.255T> C) which resulted in the exchange of phenylalanine to leucine. In FASN gene, they identified two genotypes (RS and RR). In the TE gene were identified three clones (TV, TT and UV) and sequencing resulted in the presence of 4 polymorphisms. The DGAT-1 and SCD genes do not relevaram this study, the presence of polymorphism. The results indicated that the CAST gene GDF8 gene and DGAT-2 polymorphisms showed changes in amino acid sequence and may or may not result in change in the final conformation of the protein. Already, DGAT-1 and SCD genes did not show different patterns and even SNPs and FASN gene showed only patterns of different bands, but no SNPs.