Dorn Patricia L, Melgar Sergio, Rouzier Vanessa, Gutierrez Astrid, Combe Crescent, Rosales Regina, Rodas Antonieta, Kott Sarah, Salvia Debra, Monroy Carlota M
Department of Biological Sciences, Loyola University New Orleans, 6363 St. Charles Ave, New Orleans, LA 70131, USA.
J Med Entomol. 2003 Jul;40(4):436-40. doi: 10.1603/0022-2585-40.4.436.
Trypanosoma cruzi, the hemoflagellate parasite and cause of Chagas disease in Latin America, is carried by Triatomine vectors, principally Triatoma dimidiata and Rhodnius prolixus in Central America. To assist control efforts and to understand the epidemiology of the disease in Guatemala, the population genetics of T. dimidiata was analyzed among three houses within a village and two adjacent villages in Guatemala. Eleven Randomly Amplified Polymorphic DNA-polymerase chain reaction (RAPD-PCR) primers were screened and three used to amplify bands, 29 of which were scored, from T. dimidiata DNA of approximately 50 bugs per house from three houses within a village and from 66 and 33 bugs, respectively, from adjacent villages. Results show very small genetic distances among the three T. dimidiata subpopulations from the houses (D = 0.013-0.022) and the two villages (D = 0.0199). The amount of differentiation among houses (fixation index, F(ST)) was also very small, F(ST) = 0.025 among the houses and the two villages F(ST) = 0.019. These fixation indices give an average number of mating migrants per generation (Nm) of 9.7 (among houses) and 12 (among villages). Average heterozygosity (H) appears to be high, ranging from H = 0.299-0.325 among the houses and H = 0.273 among the villages. The low genetic distance and fixation indices, and high heterozygosity suggest that the subpopulations in the houses and in the adjacent villages are not reproductively isolated but are in fact, one large panmictic population. Therefore the geographic coverage necessary for effective control must include, at least, the area encompassing adjacent villages.
克氏锥虫是一种血液鞭毛虫寄生虫，也是拉丁美洲恰加斯病的病原体，由锥蝽传播，在中美洲主要是二斑锥蝽和长红锥蝽。为了协助控制工作并了解危地马拉该疾病的流行病学情况，对危地马拉一个村庄内的三所房屋以及两个相邻村庄的二斑锥蝽群体遗传学进行了分析。筛选了11条随机扩增多态性DNA聚合酶链反应（RAPD-PCR）引物，其中3条用于扩增条带，从一个村庄内三所房屋中每所约50只二斑锥蝽的DNA中获得了29条可计分条带，相邻村庄的样本分别为66只和33只二斑锥蝽。结果显示，来自房屋的三个二斑锥蝽亚群体之间（D = 0.013 - 0.022）以及两个村庄之间（D = 0.0199）的遗传距离非常小。房屋之间的分化程度（固定指数，F(ST)）也非常小，房屋之间F(ST) = 0.025，房屋与两个村庄之间F(ST) = 0.019。这些固定指数得出每代的平均交配迁移个体数（Nm）为9.7（房屋之间）和12（村庄之间）。平均杂合度（H）似乎较高，房屋之间H = 0.299 - 0.325，村庄之间H = 0.273。低遗传距离和固定指数以及高杂合度表明，房屋和相邻村庄中的亚群体并非生殖隔离，实际上是一个大的随机交配群体。因此，有效控制所需的地理覆盖范围必须至少包括相邻村庄所在的区域。
