■来自本地品种的动物性食品的生产与区域文化具有协同关系,当地的气候,主要是对环境影响较小的系统的替代遗传资源的维护。因此,保护和生产的效率取决于评估这些当地品种的变异性。以CurraleiroPé-duro牛为例,最适应的个体在巴西稀树草原经历了五百年的自然选择,很少或没有人为干扰的交配。这些生物群落的特点,区域植物区系是食物基地,牛在广阔的地区饲养,可能影响了构成巴西第一个牛品种的不同群体的遗传组成。
■要评估成分,多样性,变异,分化,和所研究种群的遗传结构,来自不同动物类别的474个人的毛囊样本(小牛,一岁以下,小母牛,奶牛,和公牛)来自三个农场,定义为子群体“A”,\"B\",和“C”,被收集。使用DNA测序仪对动物进行17个微卫星标记的基因分型。验证单态等位基因后,超出预期大小范围的等位基因,对于口吃带的存在,对结果进行统计分析。
■所使用的标记适合于所提出的具有0.62的平均多态性信息含量(PIC)的应用。平均而言,每个标记的有效等位基因为4.25,平均杂合度为0.74(观察到的和预期的),A群(0.70)低于B群(0.77)和C群(0.74)。分子方差分析(AMOVA)显示,牛群内部的变异率较高(98.5%),而牛群之间的变异率较低(1.5%)(FST范围为0.00723和0.03198;p值<0.05)。然而,在基于地理距离的Mantel检验中发现的牛群之间没有显着差异。用软件结构采样的所有动物的遗传簇的形成导致最小簇值,在评估的动物中观察到两个主要的遗传组(K=2)。因此,基于PIC和杂合性值,观察到广泛的遗传多样性,尽管人口结构差异不大(AMOVA,FST,和结构结果)在采样点之间。
The production of animal-based foods from native breeds have a synergistic relationship with the regional culture, the local climate, and mainly the maintenance of alternative genetic resources for a system with a lower environmental impact. Thus the efficiency of conservation and production depends on assessing the variability of these local breeds. In the case of Curraleiro Pé-duro cattle, the most adapted individuals have undergone natural selection over five hundred years in the Brazilian savannas, mating with little or no human interference. The peculiarities of these biomes, where the regional flora is the food base and cattle is raised in extensive areas, likely influenced the genetic composition of the different groups that make up the first cattle breed of Brazil.
To evaluate the composition, diversity, variation, differentiation, and genetic structure of the populations studied, samples of hair follicles from 474 individuals of different animal categories (calves, yearlings, heifers, cows, and bulls) from three farms, defined as subpopulations \"A\", \"B\", and \"C\", were collected. The animals were genotyped for 17 microsatellite markers using a DNA sequencer. After verification of monomorphic alleles, alleles outside the expected size range, and for the presence of stutter bands, the results were subjected to statistical analysis.
The markers used were suitable for the proposed application with a mean Polymorphism Information Content (PIC) of 0.62. On average, the effective alleles were 4.25 per marker, with mean heterozygosities of 0.74 (observed and expected), which was lower in herd A (0.70) in comparison to herds B (0.77) and C (0.74). The analysis of molecular variance (AMOVA) revealed a higher rate of variation within herds (98.5%) and lower among herds (1.5%) (FSTranging from 0.00723 and 0.03198; p-values < 0.05). However no significant differences among herds where found with the Mantel test based on geographic distances. The formation of genetic clusters of all animals sampled with the software Structure resulted in minimum cluster values, with two main genetic groups (K = 2) observed among the evaluated animals. Therefore, based on PIC and heterozygosity values, a wide genetic diversity was observed, despite little differences in population structure (AMOVA, FST, and Structure results) among sampling sites.