Genetic variability of the Brazilian hair sheep breeds

Abstract

-The objectives of this work were to investigate the genetic structure of the Brazilian hair sheep breeds and to determine the origin of the Santa Inês breed. Molecular similarity was determined using Randomly Amplified Polymorphic DNA -Polymerase Chain Reaction markers in 238 individuals from five naturalized sheep breeds: Santa Inês (48 animals), Rabo Largo (48), Somali (48), Morada Nova (48) and Bergamasca (46), collected in Goiás, Sergipe, Bahia, and Ceará States as well as in the Federal District. Fifty-four loci were selected from 19 primers, after a pilot test using 140 primers. Qualitative analyses indicate diagnostic markers for all breeds. All breeds were significantly different from each other. Interbreed differences were explained by 14.92% of the total variation. Santa Inês clustered with Bergamasca (97% bootstrap) and with Rabo Largo, composing the third member of the group (81% bootstrap) while Morada Nova and Somali breeds clustered separately. Each breed should be considered as a separate management and conservation unit, and special care should be taken with Rabo Largo, Morada Nova and Somali breeds, represented by small herds in Brazil.

Genetic diversity and assessment of 23 microsatellite markers for parentage testing of Santa Inês hair sheep in Brazil

“…A set of 21 unrelated animals were sampled from the State of Maranhão, 25 from Ceará, 17 from Sergipe, and 15 from the Federal District in Central-West Brazil, while all 207 animals from the EMBRAPA Conservation Nucleus farm in the State of Sergipe, irrespective of relatedness, were also studied. Genomic DNA was extracted and prepared according to a protocol described earlier (Paiva et al, 2005).…”

“…Currently, however, the majority of Brazilian animals belong to hair breeds, meaning that this set of markers may not be the best choice as far as information content for identity and parentage testing. In this study, we assessed the performance of these markers together with some recently ISAG-recommended microsatellites (Glowatzki-Mullis et al, 2007) for parentage identification in Santa Inês sheep, the breed with the largest population in Brazil and the highest genetic diversity among all breeds in the country (Paiva et al, 2005). Based on a sample of 285 animals from five Santa Inês populations, we built a representative database of allele frequencies for this breed and evaluated regional differences between the animals sampled across the country.…”

Genetic improvement and population structure of the Nelore breed in Northern Brazil

“…Research and management of domestic animal populations have recently benefited from the application of molecular genetics techniques (Paiva et al, 2005;Albuquerque et al, 2006). These methods have provided significant insights into the genetic structure of economically profitable species.…”

History of registered Gyr breed in Brazilian Northeast: population structure and genetic improvement of growth traits

“…Research and management of domestic animal populations have been recently benefited by the application of molecular genetics techniques (PAIVA et al, 2005;ALBUQUERQUE et al, 2006). These methods have provided significant insights into the genetic structure of economically important species.…”