刺参尾部再生过程中形态组织细胞学初步研究

Primary study of the morphological,histological and cellular characters in tail regeneration of sea cucumber(Apostichopus japonicus Slenka)

刺参(Apostichopus japonicus Slenka)属于棘皮动物,具有很强再生能力,是中国重要的经济养殖种类。目前相关研究集中于由于诱导或自发排后的消化道再生,但是缺乏创伤后的机体修复再生(比如尾部再生)方面的研究。本研究利用传统形态学观察和组织细胞学技术对刺参尾部再生过程进行了初步探讨。研究发现,海参尾部手术切除后,可以进行再生,约15 d基本可以完成再生。海参尾部的再生类似于脊椎动物的割处再生(epimorphosis),再生时期可以分为创伤愈合期、再生胚基期和细胞分化期3个阶段。海参尾部再生过程中发生了组织溶解、组织重塑、细胞去分化、细胞增殖、细胞迁移以及细胞再分化等现象。其中,原有的肌肉细胞呈现了典型的去分化特征:肌纤维发生了明显的片段化,进一步形成小的类间质细胞。这些细胞有两个发育方向,其中一部分细胞就近再分化为肌肉细胞,进一步发生融合形成新的肌纤维;另一部分细胞则是可能迁移到伤口附近,在那里聚集和增殖,形成再生胚基。再生胚基的细胞进一步迁移和分化形成结缔组织中的成纤维细胞,参与皮下结缔组织的构建。另外,用Pax7抗体对再生的组织进行了荧光免疫组化反应,结果显示,再生过程中没有检测到明显的阳性信号,表明此过程中肌肉干细胞(卫星细胞)可能不起主要作用。本研究旨在通过阐明海参尾部再生特征,为海参养殖生产过程中正确处理和评价受伤的海参提供理论依据。

The sea cucumber（Apostichopus japonicus Slenka）, belonging to the echinoderms, is an important economic aquaculture product in China and has a strong regenerative ability. But most of the reports focus on its regeneration of the digestive tube following induced or spontaneous evisceration, and the reports about body wound healing and regeneration （such as tail regeneration） after trauma are very limited. In this paper, we studied preliminarily the process of tail regeneration in sea cucumbers using traditional morphological observation and cytohistology techniques. It was found that the sea cucumber was capable of regenerating its tail after surgical excision and the whole regeneration process took about 15 d. The tail regeneration in sea cucumbers was similar to the epimorphosis in vertebrates. The regeneration process can be divided into three stages, including wound healing, blastema and cell differentiation stage. It was revealed that tissue dissolution, tissue remodeling, tion and cell differentiation were involved in the process of the cell dedifferentiation, cell proliferation, cell migratail regeneration. Among them, the original muscle cells showed typical dedifferentiation characteristics： muscle fibers were fragmented obviously and then became small mesenchymal cells. These cells had two directions for development. Some of the cells locally re - differentiated into muscle cells and further fused into new muscle fibers ; the other part may migrate to the vicinity of the wound and form regenerative blastema through cell aggregation and proliferation. After further migration and differentiation, they would form fibroblasts, and were involved in the construction of connective tissue. In addition, we performed fluorescent immunohistochernical reaction using Pax7 antibody against regenerative tissue, and no obvious positive signals were detected. This suggested that no muscle stem cells （satellite cells） probably take part in the regeneration process. This study aimed to provide theoretical knowledge for how to deal with and assess the wounded sea cucumbers in cultivation.