COMPARATIVE NEUROENDOCRINE CONTROL OF REPRODUCTION IN MOTHS

在交配过程中，雄性Heliothis virescens将幼崽激素（JH）传递给雌性，刺激雌性内源性JH的生物合成和释放，同时抑制JH的降解，从而促进卵子成熟。这种效应被假设是通过大脑介导的，包括持续释放allattropins，刺激雌性交配体（CA）产生JH，同时释放JH酯酶抑制剂。我们使用气相色谱-质谱法测定体内JH滴度，并测量CA在体外合成和释放JH的能力，结合明确的生理实验表明，可以确定在绿芽草中看到的交配诱导产卵的机制。绿蛾很容易获得，也很容易在实验室饲养。大量关于该物种生殖生物学的研究表明，它们在生殖生理的许多方面与其他鳞翅目动物相似，因此可以作为研究鳞翅目这些过程的良好模型。本研究的重点是研究雌性绿茎海参体内JH滴度的动态变化，假设雌性海参体内内源性JH水平随着年龄的增长而下降，并且在交配时产生一种影响其大脑的雄性因子，并伴随有异位性和促性腺激素的作用。为了验证这一假设，本研究的具体目标是：1)确定雌性脑-食管下神经节（brain- seg）复合物在交配后刺激产卵中的作用；2)测定交配雌性和未交配雌性大脑seg对CA的反应；4)对绿芽草抑素进行测序。本研究的实验结果，结合同时进行的关于绿毛猴allattropin /allatostatin性质的研究数据，将为鳞翅目动物交配诱导促性腺功能的生理机制提供一个明确的解释，并增加我们对动物综合生理中神经肽与其他内分泌分泌物相互作用的认识。该项目将与堪萨斯州立大学昆虫学系主席兼教授S.B. Ramaswamy博士密切合作实施，他也同意允许研究者使用他的实验室设备。

During copulation, Heliothis virescens males transfer juvenile hormone (JH) to females and stimulate biosynthesis and release of her endogenous JH, while inhibiting JH degradation, thus stimulating egg maturation. This effect is hypothesized to be mediated via the brain, involving continued release of allatotropins that stimulates JH production by mated female corpora allata (CA) and simultaneously release of a JH-esterase inhibitor. Our ability to determine in vivo JH titers using gas chromatography-mass spectrometry and to measure in vitro JH biosynthesis and release by CA, combined with explicit physiological experiments show allow a determination of mechanisms involved in the mating-induced egg production seen in H. virescens. Heliothis virescens moths are readily available and easily reared in the laboratory. Numerous studies on the reproductive biology of this species suggest they are similar to other leptidopterans in many aspects of their reproductive physiology and, thus, serve as an excellent model to study these processes in Lepidoptera. The focus of this proposal is to study dynamics of JH titers in female Heliothis virescens, with the hypothesis that levels of endogenous JH decline with age in the virgin female and that on mating she derives a male factor that affects her brain, with a concomitant allatotropic and gonadotropic effect. The specific objectives of the proposed research to test this hypothesis are to: 1) determine the role of the female's brain- subesophageal ganglion (brain-SEG) complex in post-mating stimulation of egg production; 2) measure response of CA from mated and virgin female brain-SEG; and 4) sequence the H. virescens allatotropin. Results from experiments proposed, combined with data from concurrent studies on the nature of allatotropin/allatostatin in H. virescens, should provide a definitive explanation of the physiology of mating-induced gonadotropism in Lepidoptera, and also increase our knowledge of the interactions between neuropeptides and other endocrine secretions in the integrative physiology of animals. This project will be implemented in close collaboration with Dr. S.B. Ramaswamy, Chair and Professor, Department of Entomology, Kansas State University, who has also agreed to allow the investigator the use of his laboratory facilities.