López Diana Carolina, Jaramillo Carlos, Guhl Felipe
Centro de Investigaciones en Microbiología y Parasitología Tropical, Facultad de Ciencias, Universidad de los Andes, Bogotá D.C., Colombia.
Biomedica. 2007 Jan;27 Suppl 1:28-39.
Rhodnius prolixus is the most important vector of Chagas disease in Colombia. Genetic characterization of this species is useful to understand its potential of dispersion. The distribution of the vector and the genetic population structure are important factors for the adequate implementation of control programs and epidemiological surveillance of Chagas disease.
Genetic relationships were established for populations of R. prolixus collected from several habitat types and representative geographic areas of Colombia. A second aim was to assess its population genetic structure and dispersion across Colombia.
Genetic comparisons were made from three domestic populations of R. prolixus from (1) Tolima Province, (2) Cundinamarca Province and (3) the Sierra Nevada of Santa Marta in northern Colombia, and (4) one sylvatic population from Casanare. Two molecular techniques were used to evaluate the genetic structure of these populations-analysis of the ITS-2 of ribosomal DNA by PCR/RFLP and RAPDs.
Rhodnius prolixus shows a moderate genetic variability (Fst 0.06-0.15). Among domestic populations, the migration rates found were adequate (Nm >1) to maintain gene flow. A moderate to large degree of genetic differentiation was observed between the sylvatic population from Casanare and the domestic populations from the centre of the country (Tolima and Cundinamarca).
The domestic populations of R. prolixus are homogeneous because genetic flow exists between them, and this is favourable to chemical control, while the sylvatic population clusters apart from the domestic populations. Hence the need to study the genetic structure of the sylvatic foci, their possible dispersion routes and the epidemiological risk that they represents.
长红猎蝽是哥伦比亚恰加斯病最重要的传播媒介。对该物种进行基因特征分析有助于了解其扩散潜力。传播媒介的分布和遗传种群结构是恰加斯病防控计划和流行病学监测得以充分实施的重要因素。
确定从哥伦比亚几种栖息地类型和代表性地理区域采集的长红猎蝽种群之间的遗传关系。第二个目的是评估其在哥伦比亚的种群遗传结构和扩散情况。
对来自（1）托利马省、（2）昆迪纳马卡省和（3）哥伦比亚北部圣玛尔塔内华达山脉的三个家养长红猎蝽种群，以及（4）卡萨纳雷的一个野生种群进行了基因比较。使用了两种分子技术来评估这些种群的遗传结构——通过PCR/RFLP分析核糖体DNA的ITS-2以及随机扩增多态性DNA。
长红猎蝽显示出中等程度的遗传变异性（Fst为0.06 - 0.15）。在家养种群中，发现的迁移率足以（Nm >1）维持基因流动。在卡萨纳雷的野生种群与该国中部（托利马和昆迪纳马卡）的家养种群之间观察到中等至较大程度的遗传分化。
长红猎蝽的家养种群是同质的，因为它们之间存在基因流动，这有利于化学防治，而野生种群与家养种群聚集在一起。因此，有必要研究野生疫源地的遗传结构、其可能的扩散途径以及它们所代表的流行病学风险。
