The mud crab Scylla olivacea (Scyol) is an economically crucial crustacean species in Thailand, due to its high market demand and nutritional value. The neuropeptide F (NPF) has been implicated in the coordinated regulation of feeding and metabolism in invertebrates. While various isoforms of neuropeptide F (NPF) have been previously explored in the mud crab, some knowledge gaps in relation to the NPF family, and ambiguities in the nomenclature from previous reports, remain. In this study, NPF was firstly localized in the central nervous system and gastrointestinal tract of the mud crab, S. olivacea, using a polyclonal antibody against Macrobrachium rosenbergii, Macro-NPF. The NPF immunoreactivity (ir) was detected dominantly in the X-organ/sinus gland complex of the eyestalk (ES) and the various neuronal clusters (cluster 6, 9/11, and 14/15) and neuropils (anteromedial and posteromedial protocerebral neuropils, olfactory and accessory olfactory neuropils, and medial antennule neuropil, columnar neuropil) of the brain (BR), commissural ganglia, and suboesophageal ganglion of the ventral nerve cord (VNC). Interestingly, this study also presented the NPF immunoreactivity (NPF-ir) in the acinar gland-like cell and spindle-shaped epithelial cells of S. olivacea intestine. The full-length Scyol-NPFII was characterized by molecular cloning and revealed 414 nucleotides with 375 nucleotides of an open reading frame which encoded 124 deduced amino acids. A 124-amino acid precursor protein of Scyol-NPFII included a 26-residue signal peptide and a 69-amino acid mature peptide. The Scyol-NPFII showed the highest percentage of hit similarity to S. paramamosain-NPFII and clustered in the NPFII family, separated from the other forms of NPFs in this species. The spatial gene expression in various tissues revealed that Scyol-NPFII was found dominantly in the ES and BR, VNC, heart, intestine, and muscle. This study provided a novel form of NPF in the female mud crab, S. olivacea, which could open the possibility of its functioning in the brain-to-gut controlling axis. This study could provide essential information for further application in the cultured system of S. olivacea in the near future.

泥蟹橄榄青蟹(斯库尔) 是泰国经济上至关重要的甲壳类动物，因为其市场需求量大且营养价值高。神经肽 F (NPF) 与无脊椎动物摄食和代谢的协调调节有关。虽然之前已经在泥蟹中探索了神经肽 F (NPF) 的各种同种型，但与 NPF 家族相关的一些知识空白以及先前报告中命名的模糊性仍然存在。在本研究中，NPF首先定位于青蟹的中枢神经系统和胃肠道，S. olivacea, 使用多克隆抗体罗氏沼虾,宏-NPF。NPF 免疫反应性 (ir) 主要在眼柄 (ES) 的 X 器官/窦腺复合体和各种神经元簇（簇 6、9/11 和 14/15）和神经细胞（前内侧和后内侧前脑神经细胞）中检测到, 嗅觉和副嗅觉神经细胞, 和内侧触角神经细胞, 柱状神经细胞) 大脑 (BR), 连合神经节, 和腹神经索 (VNC) 的食管下神经节。有趣的是，这项研究还展示了腺泡样细胞和梭形上皮细胞中的 NPF 免疫反应性（NPF-ir）。S. olivacea肠。全长斯库尔-NPFII以分子克隆为特征，显示414个核苷酸和375个核苷酸的开放阅读框，编码124个推断氨基酸。一种 124 个氨基酸的前体蛋白斯库尔-NPFII 包括一个 26 个残基的信号肽和一个 69 个氨基酸的成熟肽。这斯库尔-NPFII 显示出最高百分比的命中相似性S. paramamosain-NPFII 并聚集在 NPFII 家族中，与该物种中其他形式的 NPFs 分开。不同组织中的空间基因表达表明，斯库尔-NPFII 主要存在于 ES 和 BR、VNC、心脏、肠道和肌肉中。本研究为雌性泥蟹提供了一种新形式的 NPF，S. olivacea，这可能会开启其在大脑到肠道控制轴中发挥作用的可能性。该研究可以为进一步应用在马铃薯的培养系统中提供必要的信息。S. olivacea在不远的将来。