Echinoderms occupy a key position in the evolution of deuterostomes. As such, the study of their nervous system can shed important information on the evolution of the vertebrate nervous system. However, the study of the echinoderm nervous system has lagged behind when compared to that of other invertebrates due to the lack of tools available. In this study, we tested three commercially available antibodies as markers of neural components in holothurians. Immunohistological experiments with antibodies made against the mammalian transcription factors Pax6 and Nurr1, and against phosphorylated histone H3 showed that these markers identified cells and fibers within the nervous system of Holothuria glaberrima. Most of the fibers recognized by these antibodies were co-labeled with the well-known neural marker, RN1. Additional experiments showed that similar immunoreactivity was found in the nervous tissue of three other holothurian species (Holothuria mexicana, Leptosynapta clarki and Sclerodactyla briareus), thus extending our findings to the three orders of Holothuroidea. Furthermore, these markers identified different subdivisions of the holothurian nervous system. Our study presents three additional markers of the holothurian nervous system, expanding the available toolkit to study the anatomy, physiology, development and evolution of the echinoderm nervous system.

中文翻译：

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新型标记物可识别海参神经系统的神经系统成分。

棘皮动物在后口动物的进化中占有关键地位。因此，对它们的神经系统的研究可以提供有关脊椎动物神经系统进化的重要信息。然而，由于缺乏可用的工具，棘皮动物神经系统的研究与其他无脊椎动物的研究相比落后。在这项研究中，我们测试了三种市售抗体作为海参中神经成分的标记。使用针对哺乳动物转录因子 Pax6 和 Nurr1 以及针对磷酸化组蛋白 H3 的抗体进行的免疫组织学实验表明，这些标记物鉴定了海参神经系统内的细胞和纤维。这些抗体识别的大多数纤维都与众所周知的神经标记物 RN1 共同标记。其他实验表明，在其他三种海参属物种（墨西哥海参属、克拉基钩端突触属和Sclerodactyla briareus）的神经组织中发现了类似的免疫反应性，从而将我们的发现扩展到海参科的三个目。此外，这些标记确定了海参神经系统的不同细分。我们的研究提出了海参神经系统的三个额外标记，扩展了可用的工具包来研究棘皮动物神经系统的解剖学、生理学、发育和进化。