昆虫离子转运肽(ITP)及其可变剪接变体,ITP样肽(ITP-L),属于甲壳类高血糖激素肽家族,在昆虫物种中广泛保守。虽然有限,研究已经表征了昆虫体内的ITP/ITP-L信号系统,和假定的功能,包括离子和流体传输的调节,卵巢成熟,和口渴/排泄已被提出。在这里,我们的目的是对蚊子中Itp和Itp-l的表达谱进行分子研究,埃及伊蚊,检查成人中枢神经系统内的肽免疫定位和分布,并阐明这些神经肽的生理作用。AedaeItp和AedaeItp-l的转录本表达谱揭示了成虫中不同的富集模式,AedaeItp在大脑中表达,AedaeItp-1主要在腹神经节中表达。中枢神经系统内的免疫组织化学分析显示AedaeITP肽在大脑和末端神经节的许多细胞中表达。相对而言,AedaeITP-L肽仅位于中枢神经系统的末端前腹神经节内。有趣的是,长时间的干燥应激导致成年蚊子AedaeItp和AedaeItp-l水平上调,建议在节水和喂养相关活动中可能的功能作用。RNAi介导的AedaeItp敲低导致尿液排泄增加,AedaeItp和AedaeItp-l的击倒减少了雌性的血液摄食和产卵,并阻碍了卵的生存能力,提示在生殖生理和行为中的作用。总之,这项研究确定了AedaeITP和AedaeITP-L是关键的多效性激素,调节疾病媒介中的各种关键生理过程,A.埃及伊蚊。
The insect ion transport peptide (ITP) and its alternatively spliced variant, ITP-like peptide (ITP-L), belong to the crustacean hyperglycemic hormone family of peptides and are widely conserved among insect species. While limited, studies have characterized the ITP/ITP-L signaling system within insects, and putative functions including regulation of ion and fluid transport, ovarian maturation, and thirst/excretion have been proposed. Herein, we aimed to molecularly investigate Itp and Itp-l expression profiles in the mosquito, Aedes aegypti, examine peptide immunolocalization and distribution within the adult central nervous system, and elucidate physiological roles for these neuropeptides. Transcript expression profiles of both AedaeItp and AedaeItp-l revealed distinct enrichment patterns in adults, with AedaeItp expressed in the brain and AedaeItp-l expression predominantly within the abdominal ganglia. Immunohistochemical analysis within the central nervous system revealed expression of AedaeITP peptide in a number of cells in the brain and in the terminal ganglion. Comparatively, AedaeITP-L peptide was localized solely within the pre-terminal abdominal ganglia of the central nervous system. Interestingly, prolonged desiccation stress caused upregulation of AedaeItp and AedaeItp-l levels in adult mosquitoes, suggesting possible functional roles in water conservation and feeding-related activities. RNAi-mediated knockdown of AedaeItp caused an increase in urine excretion, while knockdown of both AedaeItp and AedaeItp-l reduced blood feeding and egg-laying in females as well as hindered egg viability, suggesting roles in reproductive physiology and behavior. Altogether, this study identifies AedaeITP and AedaeITP-L as key pleiotropic hormones, regulating various critical physiological processes in the disease vector, A. aegypti.