Signaling Mechanisms in Custacean Molting Gland

甲壳动物蜕皮腺的信号机制

• 批准号: 0342982
• 负责人: Donald Mykles
• 金额: $ 38.73万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0342982&HistoricalAwards=false
• 关键词: Signaling; Mechanisms; Custacean; Molting; Gland

Growth in crustaceans requires the periodic shedding of the shell, a process called molting, which is controlled by a neurosecretory center in the eyestalks. The complex secretes molt-inhibiting hormone (MIH) that inhibits production of the molting hormone ecdysone, an ecdysteroid secreted by a pair of molting glands (Y-organs or YOs) located in the body. Thus it appears that molting is triggered by a reduction in MIH in the blood, which stimulates the molting glands to synthesize and secrete ecdysone. It is thought that binding of MIH to a membrane receptor results in a cyclic nucleotide-dependent inhibition of ecdysone-synthesizing enzymes. Five genes were cloned in the tropical land crab that may play a role in MIH signaling: nitric oxide synthase (NOS), three guanylyl cyclases (GCs), and MIH. The specific aims of the project are to determine the MIH signal transduction pathway, determine the regulation of NOS and GCs, and determine the interaction, if any, between MIH and other related hormones. Understanding the hormonal regulation of crustacean molting and growth is essential to manage fisheries, develop effective aquacultural practices, and mitigate potential effects of pollutants, such as endocrine disruptors. Despite intense effort, very little is known about the MIH signaling pathway. The identity of the membrane receptor and other components of the pathway remain unknown. Now that methods to express large amounts of active MIH are available, the MIH signaling pathway can be elucidated and potential interactions with other hormones and pollutants can be determined. The potential role of nitric oxide constitutes an entirely novel and exciting line of investigation. The project will train a postdoc, graduate student, and 4-6 undergraduates in advanced molecular biological techniques, including quantitative polymerase chain reaction (PCR).

甲壳类动物的生长需要定期脱落外壳，这一过程称为蜕皮，由眼柄中的神经分泌中心控制。该复合体分泌蜕皮抑制激素 (MIH)，抑制蜕皮激素蜕皮激素的产生，蜕皮激素是由体内一对蜕皮腺（Y 器官或 YO）分泌的蜕皮类固醇。因此，蜕皮似乎是由血液中 MIH 的减少引发的，MIH 减少会刺激蜕皮腺合成和分泌蜕皮激素。据认为，MIH 与膜受体的结合导致对蜕皮激素合成酶的环核苷酸依赖性抑制。在热带陆蟹中克隆了五个可能在 MIH 信号传导中发挥作用的基因：一氧化氮合酶 (NOS)、三种鸟苷酸环化酶 (GC) 和 MIH。该项目的具体目标是确定 MIH 信号转导途径，确定 NOS 和 GC 的调节，并确定 MIH 与其他相关激素之间的相互作用（如果有）。了解甲壳类动物蜕皮和生长的激素调节对于管理渔业、制定有效的水产养殖方法以及减轻内分泌干扰物等污染物的潜在影响至关重要。尽管付出了巨大的努力，但人们对 MIH 信号通路知之甚少。膜受体和该途径的其他成分的身份仍然未知。现在，表达大量活性 MIH 的方法已经可用，可以阐明 MIH 信号通路，并确定与其他激素和污染物的潜在相互作用。一氧化氮的潜在作用构成了一个全新且令人兴奋的研究方向。该项目将培训一名博士后、研究生和 4-6 名本科生，学习先进分子生物学技术，包括定量聚合酶链式反应 (PCR)。