【作者】 孙洋；

【导师】 王晓安；

【作者基本信息】 鲁东大学 ， 动物学， 2012， 硕士

【摘要】 薄背涡虫属于扁形动物门，涡虫纲，多肠目，海产。其取材方便并且在实验室容易培养。扁形动物在动物的进化史上占有极其特殊的地位，从扁形动物开始首次出现了两侧对称的体制、中胚层、神经中枢和感光的眼点等重要的结构，因此成为研究两侧对称起源与演化、中胚层的形成以及神经系统演化的好材料。涡虫具有极强的再生能力，所以近百年来一直是研究动物神经再生和组织器官的理想材料之一。并且涡虫与哺乳动物以及人类的许多基因的同源性很高，又具有与哺乳类相似的神经递质，因此对于涡虫神经再生机制的研究有助于人们开展对于干细胞的应用及人类相关疾病治疗等工作。本研究运用切割培养技术、常规石蜡切片方法及一步三色法对薄背涡虫再生过程各时期形态变化进行了初步研究，结果表明：薄背涡虫再生过程中有诸多机制参与，而不仅仅是单一的机制在起作用。在头、中、尾部的再生过程中，其各自的再生机制各有侧重，从而形成了不同的再生特点。总而言之，薄背涡虫的再生机制可能为：伤口处表皮细胞的迁移带动背负侧表皮的融合，由此形成伤口处的腔道，次腔道通过已分化细胞去分化形成干细胞，并且聚集由身体其它部位迁移而来的干细胞，腔道中的干细胞再迁移到伤口处分化形成伤口处不同组织的细胞，到此即完成再生过程。本研究运用乙酰胆碱酯酶组化定位法，对薄背涡虫再生过程中各时期组织变化进行了初步研究，结果表明：薄背涡虫再生各不同时期的脑神经节、横神经、神经接头及伤口周围外周神经呈阳性反应，伤口处神经网密集。新再生的组织呈白色，几乎无阳性反应。头部向后再生和中部向后再生均以长尾的方式进行，而中部向前再生和尾部向前的再生均以外包的方式进行。分析是否是因为极性的原因造成的这种再生方式。头部的再生速度最快，其次是尾部，中部再生速度最慢。这说明薄背涡虫头部、中部和尾部的再生机制是不同的。本研究运用免疫组织化学法，对薄背涡虫再生过程中各时期干细胞进行了初步定位研究，结果表明：薄背涡虫再生过程中随再生时间的增加干细胞的数量和位置都存在一定的规律性：干细胞数量随再生时间的增加先增多而后又减少。切割后干细胞先少量零星分散在脑神经节及眼点附近，随后逐渐以团状聚集并向伤口处迁移，到再生8天左右又从伤口处迁移回脑神经节附近。并且中部再生过程中发现，干细胞集中的部位是咽部、雌雄生殖器及其周围。分析是否体内咽及生殖器附近的干细胞主要用于分化成具有消化、生殖功能的细胞而不会主要用于伤口的再生修复。更多还原

【Abstract】 Notoplana humilis belongs to the Polycladida, Turbellaria, Platyhelminthes. It is freeliving, sea water platyhelminth species. It has drawn convenient, easy to train in thelaboratory, etc. Platyhelminth plays an important role in the history of animal evolution. Theyfirst inhabited bilateral symmetry and three germ layers. So the origin of the platyhelminthesis one of the most important transitions in animal evolution. From then on, morphologicalstructure and functional of animals have great developed. These developments caused thedifferentiation of the animal body function; so that platyhelminthes possess the anteriornervous system and sense organs. The nervous system is important control system, andregulates the animals’ major vital movement. Furthermore, their peripheral nervous systemhas the subepidermal plexus and submuscle plexus in the parenchyma. They have the basicmodel of the nervous system similar to the most of higher animals. Therefore, theplatyhelminthes are an important material to study the regeneration of the animal nervoussystem.This paper studied the distribution and morphology of Acetylcholine by histologicalmethods and the stem cell by immunohistochemistry methods in different stages duringNotoplana humilis regeneration. The purpose of this study is to reveal the mechanism of thenervous system during the polyclad regeneration. The results are as follows:(1)Histological and immunohistochemistry methods were used to study the stem cell inthe different stages of regeneration in Notoplana humilis. In this study, we cut the worm intothree parts-the head, the trunk and the tail. And the general histological technique was applyedto observe the regeneration of the three parts in different stages. In the end, the microstructurechange of epidermis, basement membranae, muscles, parenchymal tissue, stem cell and so onduring regeneration were discussed. we find that: when the body was cut, the migration ofneoblasts is from the ganglion to the wound; and then when the regeneration was about tocompleted, these neoblasts were came back from the wound to ganglion. Furthermore, weguess the regeneration mechanisms of regeneration such as the crasis of the dorsal and ventralepidermis, forming a cavity near the wound, the migration of neoblasts and so on.(2) Acetylcholinesterase (AChE)-positive cells and positive nerve fibers are detectedfrom the late gastrula stage of Notoplana humilis in their process of regeneration. we observed that: during rotation stage, weak positive reaction of acetylcholinesterase is locatedin the brain region of every stage. At every stage of the regeneration, the location of theAChE-positive region showed the ladder-like nervous system with the anterior pair of brain, apair of thick ventral longitudinal nerve cords that send by the brain and ventral nerve cordneural connections also showed a positive reaction of AChE staining.更多还原