Hormonal Control of Insect Epidermis

昆虫表皮的激素控制

• 批准号: 7151904
• 负责人: LYNN M RIDDIFORD
• 金额: $ 32.45万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-01-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7151904
• 关键词: Manduca; autoradiography; decarboxylases; ecdysone; enzyme substrate; flow cytometry; gene expression; gene interaction; genetic manipulation; green fluorescent proteins; hormone receptor; hormone regulation /control mechanism; immunocytochemistry; in situ hybridization; invertebrate cuticle; invertebrate embryology; juvenile hormones; metamorphosis; microarray technology; molecular cloning; molting; transcription factor; transfection

DESCRIPTION (provided by applicant): Proposed is a continuing study of the hormonal regulation of growth, molting and metamorphosis in Drosophila melanogaster, concentrating on the key role of the endocrine gland (prothoracic gland) that produces the steroid molting hormone ecdysone in size assessment and thus the timing of the onset of metamorphosis. Juvenile hormone (JH) plays an important role in allowing larval growth and molting by preventing metamorphosis. The presence of JH at the onset of the molt prevents the ecdysone-induced switch from a larval program to the metamorphic program during the molt by regulation of the ecdysone-induced transcription factor Broad. The loss of JH after the attainment of the critical size for metamorphosis then determines the final size of the larva and subsequent adult. Growth itself is dependent on the nutrient-dependent insulin signaling system. Therefore, size control depends on an interaction between the classical endocrine system and this insulin signaling system. Our specific aims in the next 4 years are: 1) To complete the study of the regulation of second pupal cuticle formation by JH, concentrating on the regulation of the Broad and Kruppel-homolog transcription factors. 2) To determine how the prothoracic gland interacts with the insulin signaling pathway and other growth factors to assess the size of the animal and signal the onset of metamorphosis. 3) To determine how JH regulates the final size at pupariation. 4) To determine what are the critical tissues for size assessment. 5) To determine how insulin signaling affects growth differentially before and after the critical weight stage. 6) To determine the role of E75A in the prothoracic gland and/or target tissues to ensure sufficient ecdysteroid for larval molting. These studies should lead to a better understanding of the ways in which JH prevents the ecdysone- induced gene switching that is necessary for metamorphosis and how the nutrition-dependent insulin signaling pathway interacts with the JH regulatory pathway so that metamorphosis occurs at a time optimal for reproduction. The control of growth and the tinning of its cessation leading to reproductive maturation is a problem that all animals including humans face. These studies in insects will provide models for the types of cellular and molecular mechanisms underlying the cessation of growth at puberty in humans. These studies also should provide new insights into how developmental switches common to all developing systems are controlled by endocrine signals. Finally, the studies may provide the basis for novel strategies of insect control that will provide for new strategies for control of the vectors of human disease such as mosquitoes and biting flies.

描述(申请人提供)：建议对黑腹果蝇生长、蜕皮和变态的激素调节进行持续研究，重点研究产生类固醇蜕皮激素蜕皮激素的内分泌腺(前胸腺)在大小评估中的关键作用以及变态开始的时间。保幼激素(JH)通过防止幼虫变态，在幼虫生长和蜕皮过程中起着重要作用。在蜕皮开始时，JH的存在通过调节蜕皮激素诱导的转录因子BRoad来阻止蜕皮激素诱导的幼虫程序切换到蜕皮过程中的变态程序。在达到变态的临界大小后，JH的丧失决定了幼虫和后续成虫的最终大小。生长本身依赖于营养依赖的胰岛素信号系统。因此，大小控制依赖于经典内分泌系统和这个胰岛素信号系统之间的相互作用。我们未来4年的具体目标是：1)完成JH对二次蛹角质层形成调控的研究，重点是对BRoad和Kruppel同源转录因子的调控。2)确定前胸腺如何与胰岛素信号通路和其他生长因子相互作用，以评估动物的大小并发出变态开始的信号。3)确定JH如何调节羽化的最终大小。4)确定评估大小的关键组织是什么。5)确定胰岛素信号在临界体重阶段前后对生长的不同影响。6)确定E75A在前胸腺和/或靶组织中的作用，以确保幼虫蜕皮有足够的蜕皮类固醇。这些研究应该有助于更好地理解JH如何阻止蜕皮激素诱导的变态所必需的基因切换，以及营养依赖型胰岛素信号通路如何与JH调节通路相互作用，从而使变态发生在生殖的最佳时间。控制生长和停止生长导致生殖成熟是包括人类在内的所有动物都面临的问题。这些对昆虫的研究将为人类青春期停止生长的细胞和分子机制类型提供模型。这些研究还应该为所有发育中系统共同的发育开关如何由内分泌信号控制提供新的见解。最后，这些研究可能为新的昆虫控制策略提供基础，这些策略将为控制蚊子和叮咬苍蝇等人类疾病的媒介提供新的策略。