MOLECULAR EVIDENCES OF MUTATION-DRIFT EQUILIBRIUM BY MICROSATELLITE MARKERS IN FOUR MEAT PRODUCER BOVINE BREEDS IN BRAZIL
Ednaldo da Silva Filho1, Juliana Simão Nina de Azevedo2, Luiz Fernando de Souza Rodrigues3, Luiz Marcelo de Lima Pinheiro4, Marcia Rocha DeRosia5, Taianara Tocantins Gomes Almeida3, Frederico Ozanan Barros Monteiro3 and José Elivalto Guimarães Campelo6.
1 Instituto de Ciências Agrárias, Universidade Federal Rural da Amazônia, Belém-Pará, Brazil.
2 Departamento de Ciências Biológicas, Universidade Federal Rural da Amazônia, Capanema-Pará, Brazil.
3 Instituto de Saúde e Produção Animal, Universidade Federal Rural da Amazônia, Belém-Pará, Brazil.
4 Departamento de Ciências Naturais, Universidade Federal do Pará, Breves-Pará, Brazil.
5 Researcher in Cirisenergy, Colorado, USA
6 Departamento de Zootecnia, Universidade Federal do Piauí, Teresina-Piauí-Pará, Brazil.
Corresponding author E-mail: silva.filho@ufra.edu.br
ABSTRACT
This study aimed to assess possible deviations in mutation-drift equilibrium in bovine breeds. A total of 178 blood samples were collected from Curraleiro Pé-Duro, Tabapuã, Guzerat and Senepol breeds for DNA extraction and genotypic analysis by eleven microsatellite markers. The deviation loci number to mutation-drift equilibrium was 1 according to allele infinity model (IAM) and 2 by the stepwise mutation model (SMM) for Curraleiro Pé-Duro breed. For Tabapuã breed, there were 5 loci by IAM, and 3 loci by SMM. Although no locus was found by IAM for Guzerat breed, 2 loci were found by SMM. 3 loci by IAM and 2 by SMM were found in Senepol breed. Sign test showed deviation of the number of loci with Heterozygosity excess applying IAM only in Tabapuã breed. In Wilcoxon breed sign test showed deviation of the number of loci with heterozygosity excess in IAM only on Curraleiro Pé-Duro, Tabapuã and Senepol breeds. Overall, the results showed presence of mutation-drift equilibrium. No potential bottleneck effect was detected by mode-shift allele distributions, therefore all breeds were in normal L-shaped. All breeds have shown evidences of mutation-drift equilibrium due more to high loci number of heterozygosity excess than deficiency of heterozygosity.
Key words: Meat cattle; IAM; SMM; Livestock production; Heterozygosity excess.
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