Laboratório de Polimorfismo do DNA, Departamento de Genética, Universidade Federal do Pará, Belém, PA Brazil.
Genet Mol Biol. 2010 Oct;33(4):774-80. doi: 10.1590/s1415-47572010000400027. Epub 2010 Dec 1.
We genotyped 15 microsatellite loci in order to evaluate the effects of habitat fragmentation, caused by flooding of the Tucuruí reservoir, on the genetic structure of Alouatta belzebul in eastern Amazonia. The analysis included two populations sampled in 1984, representing both margins of the Tocantins river, and three populations sampled 18 years later. Minimal differences in the diversity levels between present-day (Ho = 0.62-0.69 and A(R) = 6.07-7.21) and pre-flooding (Ho = 0.60-0.62 and A (R) = 6.27-6.77) populations indicated there was no significant loss of genetic variability, possibly because of successful management strategies applied during the flooding. The changes observed were limited to shifts in the composition of alleles, which presumably reflect the admixture of subpopulations during flooding. Given this, there were significant differences in the Rst values (p = 0.05) in all but one between-site comparison. Both present-day and original populations showed a deficit of heterozygotes, which suggests that this may be typical of the species, at least at a local level, perhaps because of specific ecological characteristics. The relatively large number of private alleles recorded in all populations may be a consequence of the Wahlund effect resulting from population admixture or a process of expansion rather than the loss of rare alleles through genetic drift. Additionally, the levels of genetic variability observed in this study were higher than those reported for other species of Neotropical primates, suggesting good fitness levels in these A. belzebul populations. Regular genetic monitoring of remnant populations, especially on islands, should nevertheless be an integral component of long-term management strategies.
我们对 15 个微卫星位点进行了基因分型，以评估因图库里蒂巴水库洪水而导致的栖息地破碎化对亚马逊东部东部吼猴遗传结构的影响。分析包括 1984 年采样的两个种群，代表托坎廷斯河两岸，以及 18 年后采样的三个种群。目前（Ho = 0.62-0.69 和 A(R) = 6.07-7.21）和洪水前（Ho = 0.60-0.62 和 A (R) = 6.27-6.77）种群的多样性水平差异极小表明，遗传变异性没有明显丧失，这可能是由于在洪水期间实施了成功的管理策略。观察到的变化仅限于等位基因组成的变化，这可能反映了洪水期间亚种群的混合。有鉴于此，除了一个站点之间的比较外，所有站点之间的 Rst 值（p = 0.05）都存在显著差异。目前和原始种群都表现出杂合子的缺失，这表明这可能是该物种的典型特征，至少在局部水平上是如此，这可能是由于特定的生态特征。所有种群中记录的大量特有等位基因可能是由于种群混合或扩张过程中的 Wahlund 效应，而不是遗传漂变导致稀有等位基因的丧失。此外，本研究中观察到的遗传变异性水平高于其他新热带灵长类动物的报道，这表明这些 A. belzebul 种群的适应能力良好。然而，对残余种群，特别是岛屿上的种群进行定期遗传监测，仍应成为长期管理策略的一个组成部分。
