Identificação genética e estudos populacionais utilizando microssatélites (STR) em equinos, bovinos e caninos domésticos provenientes do Uruguai, Paraguai e Brasil

Abstract

The evolution in human identification through the study of genetic markers STR (Short Tandem Repeats) induced and propitiated the growth also of animal genetic identification. However, contrary to what occurs in the human domain, animal molecular identification still lacks validation of analysis systems and population studies to be considered reliable to the degree required. Only recently the International Society for Animal Genetics (ISAG) has recommended STR markers suitable for individual discrimination in domestic animal species. Accurate animal genetic identification is sought to provide entities, associations, breeders and owners in general with assurances that their animals are in fact derived from reliable breeders. Only reliable and authentic genealogical records will ensure, for example, efficiency in genetic breeding processes. Even though it is a promising area, there are currently only two options in the market for commercial kits for animal genotyping. But its use has been deferred by specialized laboratories in the field, which end up preparing their own identification panels, using the recommended genetic markers to meet their local demands more specifically. However, if the frequencies of the alleles present in these genetic markers in the study population are not known and the real power of discrimination that they provide is not estimated, the analyzes performed and the results obtained may generate misleading or imprecise interpretations. In the present study, three panels of STR genetic markers were used with all loci recommended by ISAG, capable of identifying equine, bovine and canine individuals. Allelic frequencies and other parameters such as heterozygosity, polymorphism information content, power of exclusion and power of discrimination were obtained from significant samples in breeds present in Rio Grande do Sul (Southern Brazil), Uruguay and Paraguay, to be used in the practice of animal genetics for identification purposes. In addition, comparative population studies within and among breeds were also carried out, in order to evaluate the genetic diversity of the animal populations studied.