Ianella Patrícia, Albuquerque Maria do Socorro Maués, Paiva Samuel Rezende, Egito Andréa Alves do, Almeida Leonardo Daniel, Sereno Fabiana T P S, Carvalho Luiz Felipe Ramos, Mariante Arthur da Silva, McManus Concepta Margaret
Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, Brasília, DF, Brazil.
Embrapa Gado de Corte, Campo Grande, MS, Brazil.
Genet Mol Biol. 2017 Jul-Sep;40(3):604-609. doi: 10.1590/1678-4685-GMB-2016-0166. Epub 2017 Aug 31.
The first horses were brought to Brazil by the colonizers after 1534. Over the centuries, these animals evolved and adapted to local environmental conditions usually unsuitable for exotic breeds, thereby originating locally adapted Brazilian breeds. The present work represents the first description of maternal genetic diversity in these horse breeds based on D-loop sequences. A D-Loop HSV-I fragment of 252 bp, from 141 horses belonging to ten Brazilian breeds / genetic groups (locally adapted and specialized breeds) were analysed. Thirty-five different haplotypes belonging to 18 haplogroups were identified with 33 polymorphic sites. Haplotype diversity (varying from 0.20 to 0.96) and nucleotide diversity (varying from 0.0039 to 0.0239) was lower for locally adapted than for specialized breeds, with the same pattern observed for FST values. Haplogroups identified in Brazilian breeds are in agreement with previous findings in South American samples. The low variability observed mainly in locally adapted breeds, indicates that, to ensure conservation of these breeds, careful reproductive management is needed. Additional genetic characterization studies are required to support accurate decision-making.
1534年后，殖民者将首批马匹带到了巴西。几个世纪以来，这些动物不断进化并适应了通常不适宜外来品种生存的当地环境条件，从而产生了适应本地环境的巴西马品种。本研究首次基于D-loop序列描述了这些马品种的母系遗传多样性。对来自十个巴西马品种/遗传群体（适应本地环境的品种和专门品种）的141匹马的252 bp的D-Loop HSV-I片段进行了分析。共鉴定出属于18个单倍型组的35种不同单倍型，有33个多态性位点。适应本地环境的品种的单倍型多样性（从0.20到0.96不等）和核苷酸多样性（从0.0039到0.0239不等）低于专门品种，FST值也呈现相同模式。在巴西马品种中鉴定出的单倍型组与之前在南美样本中的研究结果一致。主要在适应本地环境的品种中观察到的低变异性表明，为确保这些品种的保存，需要谨慎的繁殖管理。还需要进行额外的遗传特征研究以支持准确的决策制定。
