Panzera Francisco, Pita Sebastián, Nattero Julieta, Panzera Yanina, Galvão Cleber, Chavez Tamara, Rojas De Arias Antonieta, Cardozo Téllez Lourdes, Noireau François
Sección Genética Evolutiva, Facultad de Ciencias, Universidad de la República, Calle: Iguá 4225, 11400, Montevideo, Uruguay.
Cátedra Introducción a la Biología, Facultad de Ciencias Exactas Físicas y Naturales, Instituto de Investigaciones Biológicas y Tecnológicas (IIByT) CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina.
Parasit Vectors. 2015 Sep 29;8:495. doi: 10.1186/s13071-015-1109-6.
Chagas disease vectors (Hemiptera-Reduviidae) comprise more than 140 blood-sucking insect species of the Triatominae subfamily. The largest genus is Triatoma, subdivided in several complexes and subcomplexes according to morphology, ecology and genetic features. One of them is the sordida subcomplex, involving four species: Triatoma sordida, T. guasayana, T. garciabesi and T. patagonica. Given the great morphological similarity of these species, their taxonomic identification, evolutionary relationships and population differentiation have been controversial for many years and even today remain under discussion.
We simultaneously analyzed two chromosomal markers, C-heterochromatin distribution and 45S ribosomal genes chromosomal position, of 139 specimens from several sordida subcomplex populations from Argentina, Bolivia, Brazil and Paraguay, collected both in nature and from several established insectaries. Our results were compared with COI sequences deposited in GenBank.
We recognized five chromosomal taxa with putative hybrids, which each differ in at least one chromosome marker. Most of them present significant differences in their mtDNA sequences.
The chromosomal taxa here show a significant chromosome differentiation involving changes in the C-heterochromatin content and in the ribosomal clusters position. This paper identifies several erroneously classified populations by morphological methods, delimits the geographical distribution of each taxon and proposes the existence of a new cryptic species, widely distributed in Argentina. We also suggest that sordida sibling species involve closely related as well as evolutionary distant species. Taxonomic status of each chromosomal taxon is discussed considering phenotypic and genetic results previously published.
恰加斯病病媒（半翅目-猎蝽科）包括锥蝽亚科140多种吸血昆虫。最大的属是锥蝽属，根据形态、生态和遗传特征可细分为几个复合体和亚复合体。其中之一是sordida亚复合体，包括四个物种：污色锥蝽、瓜氏锥蝽、加西亚贝锥蝽和巴塔哥尼亚锥蝽。鉴于这些物种在形态上极为相似，它们的分类鉴定、进化关系和种群分化多年来一直存在争议，至今仍在讨论中。
我们同时分析了来自阿根廷、玻利维亚、巴西和巴拉圭几个sordida亚复合体种群的139个标本的两个染色体标记，即C-异染色质分布和45S核糖体基因的染色体位置，这些标本既有野外采集的，也有来自几个已建立的昆虫饲养室的。我们的结果与GenBank中保存的COI序列进行了比较。
我们识别出了五个带有假定杂交种的染色体分类单元，每个分类单元至少在一个染色体标记上存在差异。它们中的大多数在mtDNA序列上存在显著差异。
这里的染色体分类单元显示出显著的染色体分化，涉及C-异染色质含量和核糖体簇位置的变化。本文通过形态学方法识别出了几个分类错误的种群，划定了每个分类单元的地理分布，并提出存在一个广泛分布于阿根廷的新隐性物种。我们还表明，sordida姐妹种包括亲缘关系密切以及进化距离较远的物种。考虑到先前发表的表型和遗传结果，讨论了每个染色体分类单元的分类地位。
