Lins R M M A, Souza N A, Peixoto A A
Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil.
Mem Inst Oswaldo Cruz. 2008 Nov;103(7):736-40. doi: 10.1590/s0074-02762008000700019.
The sandfly Lutzomyia longipalpis s.l. is the main vector of American Visceral Leishmaniasis. L. longipalpis s.l. is a species complex but until recently the existence of cryptic sibling species among Brazilian populations was a controversial issue. A fragment of paralytic (para), a voltage dependent sodium channel gene associated with insecticide resistance and courtship song production in Drosophila, was isolated and used as a molecular marker to study the divergence between two sympatric siblings of the L. longipalpis complex from Sobral, Brazil. The results revealed para as the first single locus DNA marker presenting fixed differences between the two species in this locality. In addition, two low frequency amino-acid changes in an otherwise very conserved region of the channel were observed, raising the possibility that it might be associated with incipient resistance in this vector. To the best of our knowledge, the present study represents the first population genetics analysis of insecticide resistance genes in this important leishmaniasis vector.
长须罗蛉（Lutzomyia longipalpis s.l.）是美洲内脏利什曼病的主要传播媒介。长须罗蛉（L. longipalpis s.l.）是一个复合种，但直到最近，巴西种群中隐秘同胞种的存在仍是一个有争议的问题。从果蝇中分离出一段与杀虫剂抗性和求偶鸣叫产生相关的电压依赖性钠通道基因paralytic（para）的片段，并将其用作分子标记，以研究来自巴西索布拉尔的长须罗蛉复合种的两个同域同胞种之间的差异。结果显示，para是第一个在该地区两个物种之间呈现固定差异的单基因座DNA标记。此外，在该通道一个非常保守的区域观察到两个低频氨基酸变化，这增加了其可能与该传播媒介的初始抗性相关的可能性。据我们所知，本研究是对这种重要利什曼病传播媒介中杀虫剂抗性基因的首次群体遗传学分析。
