Ruiz-Garcia Manuel, Ramirez Diana, Bello Felio, Alvarez Diana
Unidad de Genetica (Genetica de Poblaciones-Biologia Evolutiva), Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana. CRA 7a No. 43-82, Bogota DC, Colombia.
Genet Mol Res. 2003 Jun 30;2(2):229-59.
Two populations of the mosquito Psorophora columbiae from the central Andean area of Colombia and one population of Ps. toltecum from the Atlantic coast of Colombia were analyzed for 11 isoenzyme markers. Psorophora columbiae and Ps. toltecum are two of the main vectors of Venezuelan equine encephalitis. We found no conspicuous genetic differences between the two species. The relatively high gene flow levels among these populations indicate that these are not two different species or that there has been recent divergence between these taxa. In addition, no global differential selection among the loci was detected, although the alpha-GDH locus showed significantly less genetic heterogeneity than the remaining loci, which could mean that homogenizing natural selection acts at this locus. No isolation by distance was detected among the populations, and a spatial population analysis showed opposite spatial trends among the 31 alleles analyzed. Multiregression analyses showed that both expected heterozygosity and the average number of alleles per locus were totally determined by three variables: altitude, temperature and size of the human population at the locality. Individually, the expected heterozygosity is more related to these three variables than to the average number of alleles.
对来自哥伦比亚安第斯中部地区的两个哥伦比亚库蚊种群以及来自哥伦比亚大西洋沿岸的一个托尔蒂库蚊种群进行了11种同工酶标记分析。哥伦比亚库蚊和托尔蒂库蚊是委内瑞拉马脑炎的两种主要传播媒介。我们发现这两个物种之间没有明显的遗传差异。这些种群之间相对较高的基因流动水平表明，它们不是两个不同的物种，或者这些分类单元之间最近才发生分化。此外，虽然α - GDH位点的遗传异质性明显低于其余位点，这可能意味着同质化自然选择作用于该位点，但在各基因座之间未检测到全局差异选择。在种群之间未检测到距离隔离，并且空间种群分析显示在所分析的31个等位基因中存在相反的空间趋势。多元回归分析表明，预期杂合度和每个基因座的等位基因平均数完全由三个变量决定：海拔、温度和当地人口规模。单独来看，预期杂合度与这三个变量的关系比与等位基因平均数的关系更大。
