Peixoto Maria Gabriela C D, Carvalho Maria Raquel S, Egito Andrea A, Steinberg Raphael S, Bruneli Frank Ângelo T, Machado Marco Antônio, Santos Fernanda C, Rosse Izinara C, Fonseca Pablo Augusto S
Embrapa Gado de Leite, Juiz de Fora 36038-330, Brazil.
Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil.
Animals (Basel). 2021 Apr 14;11(4):1125. doi: 10.3390/ani11041125.
The Brazilian Guzerá population originated from a few founders introduced from India. These animals adapted well to the harsh environments in Brazil, were selected for beef, milk, or dual-purpose (beef and milk), and were extensively used to produce crossbred animals. Here, the impact of these historical events with regard to the population structure and genetic diversity in a Guzerá meta-population was evaluated. DNA samples of 744 animals (one dairy, nine dual-purpose, and five beef herds) were genotyped for 21 microsatellite loci. Ho, He, PIC, F, F, and F estimates were obtained considering either farms or lineages as subpopulations. Mean Ho (0.73) and PIC (0.75) suggest that genetic diversity was efficiently conserved. F, F and F values (95% CI) pointed to a low fixation index, and large genetic diversity: F (Farms = 0.021-0.100; lineages = 0.021-0.100), F (Farms = -0.007-0.076; lineages = -0.014-0.070), and F (Farms = 0.0237-0.032; lineages = 0.029-0.038). The dual-purpose herds/selection lines are the most uniform subpopulation, while the beef one preserved larger amounts of genetic diversity among herds. In addition, the dairy herd showed to be genetically distant from other herds. Taken together, these results suggest that this Guzerá meta-population has high genetic diversity, a low degree of population subdivision, and a low inbreeding level.
巴西古泽拉牛种群起源于从印度引进的少数奠基者。这些动物很好地适应了巴西的恶劣环境，被选作肉用、乳用或兼用（肉用和乳用），并被广泛用于培育杂交动物。在此，评估了这些历史事件对古泽拉复合种群的种群结构和遗传多样性的影响。对744头动物（1个奶牛群、9个兼用牛群和5个肉牛群）的DNA样本进行了21个微卫星位点的基因分型。考虑将农场或谱系作为亚种群，获得了观察杂合度（Ho）、期望杂合度（He）、多态信息含量（PIC）、F统计量（FIS、FST和FIT）的估计值。平均Ho（0.73）和PIC（0.75）表明遗传多样性得到了有效保存。FIS、FST和FIT值（95%置信区间）表明固定指数较低，且遗传多样性较大：FIS（农场=0.021 - 0.100；谱系=0.021 - 0.100），FST（农场=-0.007 - 0.076；谱系=-0.014 - 0.070），FIT（农场=0.0237 - 0.032；谱系=0.029 - 0.038）。兼用牛群/选择品系是最均匀的亚种群，而肉牛群在各牛群中保留了更多的遗传多样性。此外，奶牛群在遗传上与其他牛群距离较远。综合来看，这些结果表明这个古泽拉复合种群具有高遗传多样性、低程度的种群细分和低近亲繁殖水平。
