PSI-9 Molecular characterization of Berganês sheep, a locally adapted ecotype from Brazilian semi-arid region

Abstract The Ovis aries species is phenotypically diverse and it is bred around the world for meat, milk and wool production. In the 1980s, small farmers in the semi-arid region of Pernambuco, Brazil, initiated the introgression of genes from Santa Inês and Bergamácia breeds in their local sheep of undefined breed, and the selection of individuals in an unstructured form, giving rise to an ecotype with unique characteristics called Berganês. The aim of this study was to perform genetic structure analysis of the Berganês ecotype population on farms in the state of Pernambuco using the Illumina® BeadChip OvineSNP50 high density chip as a way of increasing knowledge about the ecotype. Animals from seven farms were genotyped, totaling 96 animals (17 males and 79 females). Of the 54,241 Single Nucleotide Polymorphism (SNPs) found, we elected the ones with GenCall Score > 0.5, Hardy-Weinberg equilibrium (significance at 0.01) and lower allele frequency (MAF) > 0.2. In addition, only SNPs located on the autosomal chromosomes were maintained, according to version 4.0 of the sheep genome, with 39,250 SNPs being selected. The observed and expected mean heterozygosity values were, respectively, 0.37159 and 0.37943. The F statistics found were: FIS = 0.02622, FST = 0 and FIT = 0.02394. Most of the variability found (97.61%), which was estimated by AMOVA, is uniformly distributed within the herds and the Principal Component Analysis (PCA) did not allow the visual identification of a substructure considering herds, sex or phenotypic characteristics (coat color, ear size and insertion, and head morphology). Thus, the genetic variability presented in the animals of the Berganês ecotype is distributed homogeneously among the herds analyzed. Therefore, the genetic characterization presented here represents a key point in the creation of conservation plans and breeding programs, improving the efficiency of selection processes and the selection of breeders.