SPECIES BOUNDARIES IN THE ANOPHELES GAMBIAE COMPLEX

首当其冲的是生活在撒哈拉以南非洲的儿童 恶性疟原虫引起的发病率和死亡率。在这里， 传统的病媒控制方法效果最差， 氯菊酯浸渍蚊帐的缓解作用受到威胁， 在主要媒介按蚊中出现氯菊酯抗性 冈比亚。 监测和管理传播的有效战略 杀虫剂抗药性的产生将取决于 病媒种群的遗传结构。 同样的信息是 对于未来的遗传控制策略至关重要， 传播媒介和非传播媒介的数量。 在这方面， 以解决不同的染色体形式的An. 冈比亚是生殖隔离，使用独立的分子 标记。 这也是这项建议的一个前提， 信息超越了一个。第二个主要病媒为冈比亚 重要的是，它的兄弟物种安。阿拉伯的。 的可能性 一个.冈比亚可能会与安杂交生产。阿拉伯语暗示 不受欢迎的特性，如杀虫剂抗性， 物种之间的交换 过去的努力最终证明 这些载体之间的基因流动由于混杂而变得复杂 解释最近的共同祖先和接触证据 关于它们在已知的物种复合体中作为姐妹类群的地位， 作为一个。冈比亚综合体。 Y染色体提供了一个强大的工具 在人口水平和更高的水平上攻击问题，不仅因为 它是非重组和父系传播，但也因为它 不能跨越障碍，因为雄性杂交种是不育的。 的主要目标 这一建议是DNA序列标记的发展和应用 在Y染色体上（微卫星，插入缺失和碱基 替代），与其他标记相结合，将有助于解决 三个相互关联的问题：（1）是一个。gambiae和An.阿拉伯的 姐妹分类群？ (2)它们之间发生了多少基因流动， 哪些基因组区域易受影响？ (3)基因流是多少 发生在染色体形式之间的。冈比亚？

It is children living in Africa south of the Sahara that bear the brunt of morbidity and mortality caused by Plasmodium falciparum. Here, traditional methods of vector control have been least effective, and the mitigating role of permethrin-impregnated bednets is threatened by emergence of permethrin resistance in the primary vector, Anopheles gambiae. Effective strategies for monitoring and managing the spread of insecticide resistance will depend upon detailed information about the genetic structure of vector populations. This same information is essential for future genetic control strategies aimed at the replacement of vector by nonvector populations. In this context, it is important to address the hypothesis that different chromosomal forms of An. gambiae are reproductively isolated, using independent molecular markers. It is also a premise of this proposal that the requisite information extends beyond An. gambiae to a second vector of major importance, its sibling species An. arabiensis. The possibility that An. gambiae may be hybridizing productively with An. arabiensis suggests that undesirable traits such as insecticide resistance could be exchanged between species. Past efforts to conclusively demonstrate gene flow between these vectors ahve been complicated by the confounding explanation of recent common ancestry and the contadictory evidence concerning their status as sister taxa within the species complex known as the An. gambia complex. The Y chromosome provides a powerful tool to attack questions at the population level and above, not only because it is nonrecombining and paternally transmitted, but also because it cannot cross barriers since male hybrids are sterile. The main goal of this proposal is the development and application of DNA sequence markers on the Y chromosome (microsatellites, insertion-deletions, and base substitutions) that, in combination with other markers, will help solve three interrelated questions: (1) Are An. gambiae and An. arabiensis sister taxa? (2) How much gene flow is occurring between them, and which genomic regions are susceptible? (3) How much gene flow is occurring between chromosomal forms of An. gambiae?