Centro Nacional de Diagnóstico e Investigación en Endemo-epidemias (CENDIE/ ANLIS-Malbrán). Av. Paseo Colón 568, CP 1063, Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, CP 1425, Ciudad Autónoma de Buenos Aires, Argentina.
Laboratorio de Eco-Epidemiología, DEGE (FCEN, UBA), IEGEBA (UBA/CONICET), Intendente Güiraldes 2160 - Ciudad Universitaria - Pabellón 2, CP 1428, Ciudad Autónoma de Buenos Aires, Argentina.
Acta Trop. 2024 Aug;256:107239. doi: 10.1016/j.actatropica.2024.107239. Epub 2024 May 10.
Chagas disease is caused by the protozoan parasite Trypanosoma cruzi (Chagas, 1909). One of the primary vectors of T. cruzi in South America is Triatoma infestans (Klug, 1834). This triatomine species is distributed across a huge latitudinal gradient, inhabiting domiciliary , peridomiciliary , and wild environments. Its wide geographic distribution provides an excellent opportunity to study the relationships between environmental gradients and intraspecific morphological variation. In this study, we investigated variations in wing size and shape in T. infestans across six ecoregions. We aimed to address the following questions: How do wing size and shape vary on a regional scale, does morphological variation follow specific patterns along an environmental or latitudinal gradient, and what environmental factors might contribute to wing variation? Geometric morphometric methods were applied to the wings of 162 females belonging to 21 T. infestans populations, 13 from Argentina (n = 105), 5 from Bolivia (n = 42), and 3 from Paraguay (n = 15). A comparison of wing centroid size across the 21 populations showed significant differences. Canonical Variate Analysis (CVA) revealed significant differences in wing shape between the populations from Argentina, Bolivia, and Paraguay, although there was a considerable overlap, especially among the Argentinian populations. Well-structured populations were observed for the Bolivian and Paraguayan groups. Two analyses were performed to assess the association between wing size and shape, geographic and climatic variables: multiple linear regression analysis (MRA) for size and Partial Least Squares (PLS) regression for shape. The MRA showed a significant general model fit. Six temperature-related variables, one precipitation-related variable, and the latitude showed significant associations with wing size. The PLS analysis revealed a significant correlation between wing shape with latitude, longitude, temperature-related, and rainfall-related variables. Wing size and shape in T. infestans populations varied across geographic distribution. Our findings demonstrate that geographic and climatic variables significantly influence T. infestans wing morphology.
恰加斯病由原生动物寄生虫克氏锥虫（Chagas，1909 年）引起。在南美洲，克氏锥虫的主要传播媒介之一是三带喙库蚊（Triatoma infestans）（Klug，1834 年）。这种半翅目昆虫分布在巨大的纬度梯度上，栖息在家庭、周边和野外环境中。其广泛的地理分布为研究环境梯度与种内形态变异之间的关系提供了极好的机会。在这项研究中，我们调查了六个生态区的三带喙库蚊的翅膀大小和形状变化。我们旨在解决以下问题：在区域尺度上，翅膀大小和形状如何变化？形态变异是否沿着环境或纬度梯度呈现特定模式？哪些环境因素可能导致翅膀变异？我们应用几何形态测量方法对来自阿根廷（n=105）、玻利维亚（n=42）和巴拉圭（n=15）的 21 个三带喙库蚊种群的 162 只雌性的翅膀进行了研究。对 21 个种群的翅膀中心大小进行比较，发现存在显著差异。典型变量分析（CVA）显示，来自阿根廷、玻利维亚和巴拉圭的种群在翅膀形状上存在显著差异，尽管存在相当大的重叠，特别是在阿根廷种群之间。玻利维亚和巴拉圭种群表现出良好的结构。为了评估翅膀大小和形状与地理和气候变量之间的关系，我们进行了两次分析：多元线性回归分析（MRA）用于大小，偏最小二乘（PLS）回归用于形状。MRA 显示出显著的总体模型拟合。六个与温度相关的变量、一个与降水相关的变量以及纬度与翅膀大小显著相关。PLS 分析显示，翅膀形状与纬度、经度、与温度相关的和与降水相关的变量之间存在显著相关性。三带喙库蚊种群的翅膀大小和形状在地理分布上存在差异。我们的研究结果表明，地理和气候变量对三带喙库蚊翅膀形态有显著影响。
