Mitochondrial control region genetic diversity and maternal ancestry of a Brangus-Ibage cattle populations.

• Autor(a) principal: HENKES, L. E.
• Data de Publicação: 2005
• Outros Autores: SILVA JUNIOR, W. A., MORAES, J. C. F., WEIMER, T. A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1094446
• topic: Brangus-Ibage; Bovino; DNA; Mitocôndria; Linhagem

The genetic diversity of 277 nucleotides in the mitochondrial DNA control region (nt 15,964 to 16,240 in reference sequence) was analyzed in crossbreed beef cattle (Brangus-Ibage, 5/8 Bos primigenius taurus x 3/8 Bos primigenius indicus) as well as in some Nellore samples (B. p. indicus). Fifty-seven mutations were found in Brangus-Ibage comprising 18 haplotypes (haplotype diversity, h = 0.851 ± 0.041 and nucleotide diversity, ntd = 0.009 ± 0.006) and 66 in Nellore (h = 1.00 ± 0.27, ntd = 0.014 ± 0.012). These data indicated sequence identities of 99.6 and 92.1% between the B. p. taurus' reference sequence and Brangus-Ibage and Nellore, respectively. The comparison of our data with sequence data for 612 individuals recovered from GenBank showed a total of 205 haplotypes defined by 99 polymorphic sites. Most of the variability (53%) was due to differentiation within breeds. The phylogenetic tree constructed using the neighbor-joining method showed clearly the well-known dichotomy between B. p. taurus and B. p. indicus. The Brangus-Ibage clustered with B. p. taurus lineages; however, the displacement of Nellore from B. p. indicus branch probably indicates a substantial B. p. taurus maternal ancestry in some Nellore samples (obtained from GenBank) and reflects the primarily male-driven introduction of this breed in Brazil.