Function of a novel male-specific gene in Aedes aegypti

描述（由申请方提供）：伊蚊是登革热、黄热病和基孔肯雅病毒的主要传播媒介。根据世界卫生组织的数据，近几十年来，登革热的全球发病率急剧增加，目前世界上近一半的人口处于危险之中。登革热没有特异性治疗方法，目前的预防完全依赖于有效的病媒控制。然而，随着抗药性的增加，病媒控制方法受到威胁。迫切需要新的战略来防治登革热和其他蚊媒疾病。目前正在探讨几种抑制或取代病媒种群的遗传战略。由于只有雌性蚊子叮咬和传播病原体，因此释放雄性蚊子是优选的，并且可能是实施这些策略所必需的。更好地了解性别决定途径将提供新的干扰目标，并导致一些实际应用。例如，可以获得赋予条件性雌性致死性的转基因品系，这将提供比当前方法更具成本效益和可扩展的仅雄性蚊子的生产。释放这种转基因雄性比释放不育雄性更有效地实现种群减少。然而，除了一些高度保守的基因，如doublemex（dsx）和transformer 2（tra 2）外，对蚊子的性别决定知之甚少。伊蚊的雄性发育是由位于1号染色体上的显性雄性决定基因座（M基因座）启动的。然而，没有M位点基因的报道。我们最近发现了一个新的男性特异性基因在Ae。埃及，我们称之为尼克斯。物理作图将nix定位在M基因座上，从未在任何雌性中检测到nix基因组DNA。没有重组检测到之间的尼克斯和M-位点时，超过5000后代进行了筛选。Nix在早期胚胎、幼虫、蛹和成年雄性睾丸中表达，但在任何成年雌性组织中不表达。此外，预测的NIX蛋白是RNA结合蛋白，其可能参与剪接。我们推测，尼克斯起着重要的作用，在性分化的Ae。埃及人。为了在这个探索性的R21项目中验证这一假设，我们将确定nix基因的异位表达（Aim 1）和敲除（Aim 2）的效果。为了确定这两种互补方法的结果，我们将监测一般表型和分子变化，并密切关注与性分化有关的变化。我们期望将我们的研究扩展到R21之外，以研究nix功能的机制，并通过操纵nix基因或其伙伴来开发蚊子控制应用。

DESCRIPTION (provided by applicant): Aedes aegpyti is a major vector of dengue, yellow fever, and chikungunya viruses. According to the World Health Organization, the global incidence of dengue has increased dramatically in recent decades and nearly half of the world population is now at risk. There is no specific treatment for dengue and current prevention depends solely on effective vector control. However, vector control methods are under threat as insecticide-resistance increases. New strategies to combat dengue and other mosquito-borne diseases are urgently needed. Several genetic strategies to suppress or replace vector populations are being explored. Since only female mosquitoes bite and transmit pathogens, the release of males is preferred and possibly required for implementation of these strategies. A better understanding of the sex-determination pathway will provide novel targets for interference and lead to several practical applications. For example, transgenic lines may be obtained that confer conditional female lethality, which will provide more cost-effective and scalable production of male-only mosquitoes than current approaches. Release of such transgenic males is more effective at achieving population reduction than sterile male release. However, little is known about sex determination in mosquitoes except for a few highly conserved genes such as doublesex (dsx) and transformer2 (tra2). Male development in Aedes mosquitos is initiated by a dominant male-determining locus (M-locus) located on the chromosome 1. However, no M-locus genes have been reported. We recently identified a novel male-specific gene in Ae. aegypti, which we named nix. Physical mapping places nix at the M-locus and nix genomic DNA was never detected in any female. No recombination was detected between nix and the M-locus when more than 5000 offspring were screened. Nix is expressed in the early embryo, larvae, pupae, and adult male testis, but not in any adult female tissues. Furthermore, the predicted NIX protein is an RNA-binding protein which may be involved in splicing. We hypothesize that nix plays an important role in sexual differentiation in Ae. aegypti. To test the hypothesis during thi exploratory R21 project, we will determine the effect of both ectopic expression (Aim 1) and knockout (Aim 2) of the nix gene. To determine the outcome of the two complementary approaches, we will monitor general phenotypic and molecular changes and pay close attention to those related to sexual differentiation. We anticipate extending our research beyond this R21 to investigate the mechanism of nix function and develop mosquito control applications through manipulation of the nix gene or its partners.