Ferreira J S B, Paiva S R, Silva E C, McManus C M, Caetano A R, Façanha D A E, de Sousa M A N
Programa de Pós-Graduação em Produção Animal, Universidade Federal Rural do Semi-Árido, Mossoró, RN, Brasil.
Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brasil
Genet Mol Res. 2014 Apr 3;13(2):2480-90. doi: 10.4238/2014.April.3.20.
The aim of this study was to analyze genetic diversity and population structure among varieties of White (N = 40), Red (N = 32), and Black (N = 31) Morada Nova hair sheep from flocks in the northeastern Brazilian semiarid region. Fifteen nuclear microsatellite markers and two regions of mitochondrial DNA were used. The intra-population analysis demonstrated that the White variety had higher diversity, while the Red variety had the lowest values. The Bayesian analysis to assess the genetic population structure allowed differentiation between White, Red, and Black varieties, and revealed a tendency towards sub-structuring in the White variety flocks from the States of Ceará and Paraíba. The results of analyses of molecular variance showed that the greatest genetic structure was found when comparing flocks rather than varieties (8.59 vs 6.64% of the total variation, P < 0.001). Based on genetic distance, Dtl, both the dendrogram analysis and the principal coordinate analysis showed the formation of two main groups: one composed of White and another of Black and Red individuals. Five and two haplotypes were found for the D-loop region and the ND5 gene, respectively. A haplotype unique to the Red variety was found in the D-loop region and a variety haplotype unique to the Black variety was found in the ND5 gene; however, these frequencies were low and therefore require further validation. These results support the existence of substantial differences between the Red and White varieties and should be used as separate genetic resources and to improve conservation programs.
本研究旨在分析来自巴西东北部半干旱地区畜群的白色（N = 40）、红色（N = 32）和黑色（N = 31）莫拉达诺瓦毛羊品种之间的遗传多样性和群体结构。使用了15个核微卫星标记和线粒体DNA的两个区域。群体内分析表明，白色品种具有更高的多样性，而红色品种的值最低。评估遗传群体结构的贝叶斯分析能够区分白色、红色和黑色品种，并揭示了来自塞阿拉州和帕拉伊巴州的白色品种畜群存在亚结构倾向。分子方差分析结果表明，比较畜群而非品种时发现的遗传结构最大（分别占总变异的8.59%和6.64%，P < 0.001）。基于遗传距离Dtl，聚类分析和主坐标分析均显示形成了两个主要群体：一个由白色个体组成，另一个由黑色和红色个体组成。D-loop区域和ND5基因分别发现了5个和2个单倍型。在D-loop区域发现了红色品种特有的一个单倍型，在ND5基因中发现了黑色品种特有的一个品种单倍型；然而，这些频率较低，因此需要进一步验证。这些结果支持红色和白色品种之间存在显著差异，应将它们作为单独的遗传资源并用于改进保护计划。
