Physiology of Mosquito Behavior

蚊子是每年将疾病传播给数亿人的罪魁祸首。蚊子数量庞大是由于其有效的生殖系统将雌蚊摄取的血液中的蛋白质转化为卵。当雄蚊与雌蚊交配时，雄蚊会将精子和附属生殖腺中的物质转移到雌蚊身上，这些物质会改变雌蚊的生理机能。在它们的众多影响中，雄性副腺物质阻止了大多数物种的雌性再次交配。在第一次交配后，精子被储存在一个特殊的囊中，即精囊，在她的余生中，这些精子被释放出来，使每一批产下的卵子受精。该实验室最近的工作表明，在最重要的疟疾媒介冈比亚按蚊中，雄性副腺不像在其他蚊子中那样控制交配行为。然而，交配确实以某种方式改变了雌性的行为和其角质层的碳氢化合物成分，这可能是该物种的雄性用来区分未交配或已交配的雌性的线索。初步实验表明，雌性精子囊中含有的精子可能会阻止其繁殖。从这项工作中出现的另一个有趣的差异是男性安的精子多态性的证明。冈比亚按蚊;与大多数其他种类的蚊子不同，雄冈比亚蚊产生的精子长度变化很大，但只有较长的精子才能进入雌蚊的精囊。本项目的目的是研究黄芪表皮改变的机制。冈比亚，它在交配中的作用，以及男性产生不同类型精子的可能原因。采用气相色谱法测定经各种实验处理后雌蚊表皮碳氢化合物的变化，确定对其交配的阻碍程度。男性在接受激素等各种治疗后产生的精子将在显微镜下进行检查，并在男性和女性的生殖道内测量精子的长度和细胞核的存在。该项目的长期重要性在于，它将提供关于世界上最重要的蚊子媒介交配系统的急需信息。如果要利用基因工程的工具，将新的基因引入蚊子种群，以防止它们传播传染因子，那么必须更好地了解引入这些基因的基本交配机制。

Mosquitoes are responsible for the transmission of agents of disease to hundreds of millions of people each year. Their large populations are the result of an efficient reproductive system that converts the protein contained in the blood that the female mosquito ingests into eggs. When they mate with females, male mosquitoes transfer sperm as well as substances from their accessory reproductive glands and these substances alter the female's physiology. Among their many effects, the male accessory gland substances prevent the females of most species from ever mating again. After the first mating, sperm are stored in a special sac, the spermatheca, for the rest of her life and these are released to fertilize each batch of eggs as it is laid. Recent work in this laboratory has demonstrated that in the most important mosquito vector of malaria, Anopheles gambiae, male accessory glands do not control mating behavior as they do in other mosquito species. Mating does, however, somehow alter the female's behavior and the hydrocarbon composition of her cuticle, which may be the cue that males of this species use to distinguish unmated or previously mated females. Preliminary experiments suggest that sperm contained in the spermatheca of the female may prevent her from remating. Another interesting difference that emerged from this work was the demonstration of a sperm polymorphism in male An. gambiae; unlike most other mosquito species, male gambiae produce sperm of considerably variable lengths, but only the longer sperm end up in the female's spermatheca. The goals of this project are to examine the mechanism of cuticular alteration in An. gambiae, its role in mating, and the possible reasons for the varying types of sperm produced by the male. The change in cuticular hydrocarbons of female mosquitoes will be assessed by gas chromatography after various experimental treatments and the degree to which mating is prevented will be determined. Sperm that are produced by males after various treatments such as hormone administration will be examined microscopically and measured for length and presence of a nucleus, both within the genital tracts of the male and female. The long-term importance of this project is that it will provide much needed information about the mating systems of the most important mosquito vector in the world. If, using tools of genetic engineering, new genes are to be introduced into mosquito populations to prevent them from transmitting infectious agents, the basic mechanisms of mating by which those genes are to be introduced must be better understood.