Arrivillaga Jazzmin, Salerno Patricia, Rangel Yadira
Ecología molecular de insectos vectores, Universidad Simón Bolívar, Caracas, Sarteneja, Venezuela.
Rev Biol Trop. 2009 Mar-Jun;57(1-2):23-31.
Lutzomyia pseudolongipalpis and Lutzomyia longipalpis (species C2, L. sp n.) are two endemic species of Phlebotominae sand fly vectors from Venezuela. The two insects are sympatric and monophyletic but have deeply diverging, morphological differences. They belong to the L. longipalpis complex. A study of their reproductive isolation is necessary to understand the process of speciation and maintenance of the two sister species as two discrete taxonomic and biological entities. Cross-mating tests were conducted (homo and hetero-specific) and monitored under two criteria: biological (presence of copulation and offspring) and genetic (using two isozymic markers diagnostic for the L. longipalpis complex; enzyme diagnosis AK and HK). Results indicate reproductive isolation, with an asymmetrical genetic exchange in a direction of hybridization between the two species under experimental conditions, and production of a low number of heterozygotes. These findings support the existence of negative selection on hybrids, and explain the absence of hybrids under natural conditions, in the sympatric locality.
伪长须罗蛉和长须罗蛉（C2物种，罗蛉新物种）是来自委内瑞拉的白蛉亚科沙蝇媒介的两个特有物种。这两种昆虫同域分布且为单系群，但在形态上有很大差异。它们属于长须罗蛉复合体。对它们的生殖隔离进行研究对于理解这两个姊妹物种作为两个不同的分类和生物学实体的物种形成和维持过程是必要的。进行了杂交交配试验（同种和异种），并根据两个标准进行监测：生物学标准（交配和后代的存在情况）和遗传学标准（使用两种诊断长须罗蛉复合体的同工酶标记；AK和HK酶诊断）。结果表明存在生殖隔离，在实验条件下两个物种之间杂交方向上存在不对称的基因交换，并且产生的杂合子数量较少。这些发现支持对杂种存在负选择，并解释了在同域分布地区自然条件下杂种不存在的原因。
