Nattero Julieta, Pita Sebastián, Calleros Lucía, Crocco Liliana, Panzera Yanina, Rodríguez Claudia S, Panzera Francisco
Cátedra de Introducción a la Biología, Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas -IIByT (CONICET-Universidad Nacional de Córdoba). Avda. Vélez Sarsfield, piso 2, Córdoba, Argentina.
Present address: Laboratorio de Eco-Epidemiología, Instituto de Ecología, Genética y Evolución de Buenos Aires, CONICET, EGE, FCEyN, UBA, Intendente Güiraldes 2160-Ciudad Universitaria-Pabellón 2, Buenos Aires, Argentina.
PLoS One. 2016 Dec 22;11(12):e0168853. doi: 10.1371/journal.pone.0168853. eCollection 2016.
The epidemiological importance of Chagas disease vectors largely depends on their spreading ability and adaptation to domestic habitats. Triatoma patagonica is a secondary vector of Chagas disease endemic of Argentina, and it has been found colonizing domiciles and most commonly peridomiciliary structures in several Argentine provinces and morphological variation along its distribution range have been described. To asses if population differentiation represents geographic variants or true biological species, multiple genetic and phenotypic approaches and laboratory cross-breeding were performed in T. patagonica peridomestic populations. Analyses of chromatic variation of forewings, their size and the content of C-heterochromatin on chromosomes revealed that populations are structured following a North-South latitudinal variation. Cytochrome c oxidase I mitochondrial gene (COI) nucleotide analysis showed a mean genetic distance of 5.2% between the most distant populations. The cross-breeding experiments suggest a partial reproductive isolation between some populations with 40% of couples not laying eggs and low hatching efficiency. Our findings reveal phenotypic and genetic variations that suggest an incipient differentiation processes among T. patagonica populations with a pronounced phenotypic and genetic divergence between the most distant populations. The population differentiation here reported is probably related to differential environmental conditions and it could reflect the occurrence of an incipient speciation process in T. patagonica.
恰加斯病病媒的流行病学重要性很大程度上取决于它们的传播能力和对家庭栖息地的适应能力。巴塔哥尼亚锥蝽是阿根廷地方性恰加斯病的次要病媒，已发现它在阿根廷几个省份的家庭和最常见的住宅周围结构中定殖，并且已经描述了其分布范围内的形态变异。为了评估种群分化是代表地理变种还是真正的生物物种，对巴塔哥尼亚锥蝽住宅周围种群进行了多种遗传和表型方法以及实验室杂交试验。对前翅的颜色变异、大小以及染色体上C-异染色质的含量进行分析后发现，种群是按照南北纬度变异构建的。细胞色素c氧化酶I线粒体基因（COI）核苷酸分析显示，距离最远的种群之间的平均遗传距离为5.2%。杂交试验表明，一些种群之间存在部分生殖隔离，40%的配对不产卵且孵化效率低。我们的研究结果揭示了表型和遗传变异，表明巴塔哥尼亚锥蝽种群之间正在进行初步分化过程，距离最远的种群之间存在明显的表型和遗传差异。这里报道的种群分化可能与不同的环境条件有关，并且可能反映了巴塔哥尼亚锥蝽正在发生的物种形成初期过程。
