The crustacean stomatogastric nervous system (STNS) is a well-known model for investigating neuropeptidergic control of rhythmic behavior. Among the peptides known to modulate the STNS are the C-type allatostatins (AST-Cs). In the lobster, Homarus americanus, three AST-Cs are known. Two of these, pQIRYHQCYFNPISCF (AST-C I) and GNGDGRLYWRCYFNAVSCF (AST-C III), have non-amidated C-termini, while the third, SYWKQCAFNAVSCFamide (AST-C II), is C-terminally amidated. Here, antibodies were generated against one of the non-amidated peptides (AST-C I) and against the amidated isoform (AST-C II). Specificity tests show that the AST-C I antibody cross-reacts with both AST-C I and AST-C III, but not AST-C II; the AST-C II antibody does not cross-react with either non-amidated peptide. Wholemount immunohistochemistry shows that both subclasses (non-amidated and amidated) of AST-C are distributed throughout the lobster STNS. Specifically, the antibody that cross-reacts with the two non-amidated peptides labels neuropil in the CoGs and the stomatogastric ganglion (STG), axons in the superior esophageal (son) and stomatogastric (stn) nerves, and ~ 14 somata in each commissural ganglion (CoG). The AST-C II-specific antibody labels neuropil in the CoGs, STG and at the junction of the sons and stn, axons in the sons and stn, ~ 42 somata in each CoG, and two somata in the STG. Double immunolabeling shows that, except for one soma in each CoG, the non-amidated and amidated peptides are present in distinct sets of neuronal profiles. The differential distributions of the two AST-C subclasses suggest that the two peptide groups are likely to serve different modulatory roles in the lobster STNS.

中文翻译：

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C型alotastatin（AST-C）家族的非酰胺化和酰胺化成员在美国大螯虾Homarus americanus的胃胃神经系统中差异分布。

甲壳动物的胃胃神经系统（STNS）是用于研究节律行为的神经肽能控制的著名模型。已知可调节STNS的肽包括C型allatostatin（AST-Cs）。在龙虾，美洲大螯虾，三个AST-C是已知的。其中两个pQIRYHQCYFNPISCF（AST-C I）和GNGDGRLYWRCYFNAVSCF（AST-C III）具有未酰胺化的C末端，而第三个SYWKQCAFNAVSCFamide（AST-C II）被C末端酰胺化。在此，产生了针对一种非酰胺化肽（AST-C I）和酰胺化同工型（AST-C II）的抗体。特异性测试表明AST-C I抗体与AST-C I和AST-C III交叉反应，但与AST-C II不交叉反应。AST-C II抗体不会与任何未酰胺化的肽交叉反应。整个免疫组织化学表明，AST-C的两个亚类（非酰胺化和酰胺化）均分布在整个龙虾STNS中。具体来说，与这两种未酰胺化的肽发生交叉反应的抗体会标记CoGs和胃胃神经节（STG）中的Neuropil，食管上端的轴突（儿子和胃气（stn）神经，以及每个连合神经节（CoG）中的〜14个躯体。在AST-C II特异性抗体标记神经纤维网在嵌齿，STG，并在交界处儿子S和STN，在轴突儿子S和STN，〜42胞体中的每个COG，以及两个胞体在STG。双重免疫标记显示，除了每个CoG中的一个体细胞外，未酰胺化和酰胺化的肽存在于不同的神经元谱中。两个AST-C亚类的差异分布表明，两个肽基可能在龙虾STNS中起不同的调节作用。