Neuropeptides of short neuropeptides F family (sNPF) have been identified in various arthropods. They are pleiotropic neuromolecules which so far have been mainly associated with regulation of feeding and metabolism, as well as growth and development, locomotion, circadian rhythm or learning and memory. Here, we describe the effects of Tenebrionid sNPF peptide (SGRSPSLRLRFa) on various aspects of the male reproductive physiology in the Tenebrio molitor beetle. We identified in silico the putative sNPF receptor Tenmo-sNPFR. Based on RT-PCR technique, it was shown that the receptor might be present in the male reproductive tissues of this beetle. The analysis of receptor amino acid sequence showed that it is similar to other beetle sNPFRs, as well as other insect species, and belongs rhodopsin-like G-protein-coupled receptors (GPCRs). Injections of Trica-sNPF and its shorter form Trica-sNPF(4–11) caused differentiated effects in T. molitor male reproductive tissues. After 24 h post injections, the peptides decreased the concentration of the soluble protein fraction in testes of 4- and 8-day-old beetles as well as the dry mass of these organs but only in 8-day-old individuals. The same effects were shown with regard to accessory glands. Both peptides decrease the concentration of the soluble protein fraction but do not affect the dry mass of this organ. Furthermore, injections of Trica-sNPF at the 10–7 M concentration decrease the total sperm number in the reproductive system. Surprisingly, the same concentration of the shorter form, Trica-sNPF(4–11) increased the sperm number. It was also shown that both peptides in different manner influence contractions of ejaculatory duct. The data presented in this article give new evidence that sNPFs are involved in the regulation of reproductive events in beetles, which might be the part of a larger neuropeptide network combining feeding, growth and development with the physiology of reproduction.

中文翻译：

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短神经肽 F 信号调节黄粉虫雄性生殖系统的功能

已在各种节肢动物中鉴定出短神经肽 F 家族 (sNPF) 的神经肽。它们是多效性神经分子，迄今为止主要与调节摄食和新陈代谢以及生长发育、运动、昼夜节律或学习和记忆有关。在这里，我们描述了 Tenebrionid sNPF 肽 (SGRSPSLRLRFa) 对黄粉虫雄性生殖生理学各个方面的影响。我们在计算机中确定了推定的 sNPF 受体 Tenmo-sNPFR。基于RT-PCR技术，表明该受体可能存在于该甲虫的雄性生殖组织中。受体氨基酸序列分析表明，它与其他甲虫sNPFRs以及其他昆虫物种相似，属于视紫红质样G蛋白偶联受体(GPCRs)。注射 Trica-sNPF 及其较短形式的 Trica-sNPF(4–11) 在 T. molitor 雄性生殖组织中引起分化效应。注射后 24 小时后，肽降低了 4 日龄和 8 日龄甲虫睾丸中可溶性蛋白质部分的浓度以及这些器官的干质量，但仅限于 8 日龄个体。附属腺体也显示出相同的效果。两种肽都会降低可溶性蛋白质部分的浓度，但不会影响该器官的干质量。此外，注射 10–7 M 浓度的 Trica-sNPF 会降低生殖系统中的精子总数。令人惊讶的是，相同浓度的较短形式 Trica-sNPF(4–11) 增加了精子数量。还显示两种肽以不同方式影响射精管的收缩。