Programa de Biología Celular y Molecular, ICBM, Facultad de Medicina, Universidad de Chile, Casilla 70086, Santiago 7, Chile.
Infect Genet Evol. 2011 Mar;11(2):329-33. doi: 10.1016/j.meegid.2010.11.002. Epub 2010 Nov 24.
Mepraia is an endemic genus found in the semiarid and arid regions of north-central Chile. Until 1998, Mepraia spinolai was the only species of the genus, distributed in coastal and interior valleys from Chile between 18° and 34°S. However, on the basis of karyotype and morphological characters, coastal desert populations between 18° and 26°S were ranked as a new species, Mepraia gajardoi. Recently, genetic studies using nuclear and mitochondrial markers on Mepraia populations suggest that the geographical criterion to separate the two species should be reviewed. Mepraia species show conspicuous alary polymorphism, unique in the Triatominae subfamily. Females of both species are invariably micropterous, while males of M. spinolai can be micropterous, brachypterous or macropterous, and only brachypterous in M. gajardoi. In this study, we use geometric morphometrics analyses to compare male wings of M. spinolai and M. gajardoi from natural populations, in order to examine if these two species have diverged in alary shape. As expected, we found that brachypterous wings of both species are smaller than macropterous wings of M. spinolai. Additionally, we detected clear differences in shape on wings of M. gajardoi and M. spinolai, not attributable to allometric effects. For last, a new alary phenotype, insects with vestigial wings, was described here for the first time. In conclusion, our analyses on wings of Mepraia species separate two distinct groups consistent with the two described species. However, our findings of vestigial wings in some coastal areas of the north part of Chile cannot rule out the existence of a hybrid zone.
梅普拉亚是一个地方性属，分布在智利中北部的半干旱和干旱地区。直到 1998 年，Mepraia spinolai 是该属的唯一物种，分布在智利南部 18°至 34°之间的沿海和内陆山谷。然而，基于核型和形态特征，18°至 26°S 沿海沙漠地区的种群被列为一个新物种，Mepraia gajardoi。最近，对梅普拉亚种群的核型和线粒体标记的遗传研究表明，应重新审查将这两个物种分开的地理标准。梅普拉亚物种表现出明显的翅型多态性，在三锥虫亚科中是独一无二的。两种物种的雌性都是微小翅型，而 M. spinolai 的雄性可以是微小翅型、短翅型或长翅型，而 M. gajardoi 的雄性则只有短翅型。在这项研究中，我们使用几何形态测量学分析来比较来自自然种群的 M. spinolai 和 M. gajardoi 的雄性翅膀，以检验这两个物种的翅型是否已经发生了分化。正如预期的那样，我们发现两种物种的短翅型翅膀都比 M. spinolai 的长翅型翅膀小。此外，我们还发现 M. gajardoi 和 M. spinolai 的翅膀形状存在明显差异，这不是由大小比例效应引起的。最后，我们首次在这里描述了一种新的翅型表型，即具有退化翅膀的昆虫。总之，我们对梅普拉亚物种翅膀的分析将两个不同的群体分开，与描述的两个物种一致。然而，我们在智利北部沿海地区发现的一些退化翅膀的存在不能排除存在杂交区的可能性。
