ABSTRACT The objective of this study was to assess the genetic structure and diversity of six Santa Inês sheep flocks from the Central-Northern Brazil. A panel of 20 highly polymorphic and informative microsatellite loci was selected and amplified. The following parameters were obtained: overall mean of number of alleles = 15.4; expected heterozygosity (He) = 0.89; polymorphism information content (PIC) = 0.88; discriminatory capacity = 0.95; combined probability of identity = 1.50 × 10−34; and probability of exclusion = 1.00. The flocks with the lowest and the highest degrees of genetic variability were Farm 6 (He = 0.70, PIC = 0.653, and allelic richness [Ar] = 3.76) and Farm 1 (He = 0.89, PIC = 0.882, and Ar = 4.39), respectively. Indications of genetic bottleneck were observed in all flocks, as well as moderate genetic differentiation, with FST = 0.053, RST = 0.096, and Dest = 0.169. The migration rate in all flocks was high, with a trend towards Farm 1. This finding was not in agreement with the substructure found with the Bayesian admixture analysis and corroborated the array obtained with the principal component analysis and the clustering analysis. The results revealed moderate structuring and high genetic diversity in the flocks. However, management strategies should be reviewed, as evidence of bottleneck and genetic erosion was observed. CentralNorthern Central Northern Brazil 2 amplified 15.4 154 15 4 He 0.89 089 0 89 (PIC 0.88 088 88 0.95 095 95 150 50 1.5 10−34 1034 10 34 100 00 1.00 070 70 0.70 0653 653 0.653 [Ar 3.76 376 3 76 0882 882 0.882 4.39, 439 4.39 , 39 4.39) respectively differentiation 0053 053 0.053 0096 096 0.096 0169 169 0.169 However reviewed 15. 0.8 08 8 0.9 09 9 5 10−3 103 1.0 07 7 0.7 065 65 0.65 3.7 37 43 4.3 005 05 0.05 009 0.09 016 16 0.16 0. 10− 06 0.6 3. 4. 0.0 01 0.1

ResumoObjetivou-se avaliar a diversidade genética de ovinos Santa Inês em fazendas no Estado do Piauí, utilizando marcadores RAPD. Foram analisados 164 espécimes pertencentes a seis municípios das mesorregiões Centro-Norte e Sudoeste. Após a obtenção do DNA, avaliou-se o potencial de 34 iniciadores, dos quais apenas cinco mostraram bandas passíveis de análise. Foram amplificados 37 locos distintos, sendo 36 polimórficos. Apesar do alto polimorfismo geral (97,2%) a taxa de polimorfismo intrapopulacional foi reduzida (média = 69,82%/população), mostrando que o conjunto dos rebanhos apresenta alta diversidade, mas que cada população isolada pode estar sofrendo efeitos da endogamia. Os índices de diversidade genética (Hs) e de endogamia (f) apresentaram, respectivamente, valores de 0,289 e 0,172. Ambos indicaram excesso de homozigotos e consanguinidade positiva dentro das fazendas. A composição dos rebanhos amostrados quase exclusivamente por fêmeas pode ser a justificativa para esses resultados, onde as proles são compostas principalmente por meio-irmãos. Os resultados acima citados foram confirmados pelos testes de AMOVA (ΦST= 0,199), que mostrou diferenças genéticas significativas entre fazendas, e pelas análises do programa Structure, que indicaram a presença de três grupos genéticos distintos, podendo esta ser uma evidência da presença de animais pertencentes ao “Novo Santa Inês”, entre os ovinos amostrados.

AbstractThis study aimed to evaluate the genetic diversity of Santa Inês sheep in Piauí state farms using RAPD markers. A total of 164 specimens belonging to six cities of Central-Northern and Southwestern regions were analyzed. After isolating the DNA, we assessed the potential of 34 primers, of which only five showed bands with sufficient resolution. Thirty-seven distinct loci were amplified, of which 36 were polymorphic. Despite the overall high polymorphism (97.2%) the rate of polymorphism within each population was reduced (mean = 69.82%/population), showing that all the herds have a high diversity but that each isolated population may be suffering the effects of inbreeding. The indices of genetic diversity (Hs) and inbreeding (f) showed, respectively, values of 0.289 and 0.172. Both showed homozygote excess and positive consanguinity within the farms. The composition of the sampled herds almost exclusively by females may be the explanation for these results, where half-brothers compose most of the offspring. The above results were confirmed by AMOVA tests (ΦST = 0.199), which showed significant genetic differences between farms. Also, the analysis of Structure software indicated the presence of three distinct genetic groups, which may characterize the occurrence of animals belonging to the "New Santa Inês" among the sampled sheep.

The objective of this study was to characterize the genetic variability of Anglo-Nubian goats using microsatellite markers. The study was conducted using herds from four municipalities of Central-Northern Piauí (Teresina, José de Freitas, Campo Maior, and Angical), where technical information is scarce. Seven markers suggested by FAO were used (ILSTS11, McM527, INRA23, ETH10, OarfCB304, OarfCB48, and MAF209). The samples were genotyped using a 7% polyacrylamide gel. The average number of alleles per locus was 4.0, with observed and expected heterozygosity of 0.38 and 0.55, respectively. Few deviations from the Hardy-Weinberg equilibrium were observed for each population. Only two loci deviated significantly in two localities. The coefficient of gene differentiation (GST') indicated that 11.9% of the genetic variation was distributed among populations, and according to the coefficient of inbreeding (GIS = 0.23 and FIS = 0.23), there is a deficiency of heterozygotes within populations. These findings corroborate the Bayesian analyses performed with the STRUCTURE software, which revealed three distinct and moderately structured groups. The graphic analysis showed that Teresina and José de Freitas are isolated groups, while Angical and Campo Maior share most of their alleles. Despite this, the level of diversity among herds was low. Based on this genetic structure, exchange of reproducers among municipalities is recommended for the maintenance of the breed.