PDF(Pubmed)
Abstract：
In recent years, interest in the possible molecular regulators of cell proliferation and differentiation in a wide range of regeneration models has grown significantly, but the cell kinetics of this process remain largely a mystery. Here we try to elucidate the cellular aspects of regeneration by EdU incorporation in intact and posteriorly amputated annelid Alitta virens using quantitative analysis. We found that the main mechanism of blastema formation in A. virens is local dedifferentiation; mitotically active cells of intact segments do not significantly contribute to the blastemal cellular sources. Amputation-induced proliferation occurred predominantly within the epidermal and intestinal epithelium, as well as wound-adjacent muscle fibers, where clusters of cells at the same stage of the cell cycle were found. The resulting regenerative bud had zones of high proliferative activity and consisted of a heterogeneous population of cells that differed in their anterior-posterior positions and in their cell cycle parameters. The data presented allowed for the quantification of cell proliferation in the context of annelid regeneration for the first time. Regenerative cells showed an unprecedentedly high cycle rate and an exceptionally large growth fraction, making this regeneration model especially valuable for studying coordinated cell cycle entry in vivo in response to injury.
摘要：
近年来,在广泛的再生模型中，对细胞增殖和分化的可能分子调节剂的兴趣显着增长，但是这个过程的细胞动力学在很大程度上仍然是个谜。在这里，我们尝试通过定量分析，通过将EdU掺入完整和向后截肢的环形物Alittavirens中，阐明再生的细胞方面。我们发现A.virens中胚芽形成的主要机制是局部去分化；完整节段的有丝分裂活性细胞对胚芽细胞来源没有显着贡献。截肢诱导的增殖主要发生在表皮和肠上皮内，以及伤口附近的肌肉纤维，发现处于细胞周期相同阶段的细胞簇。所得的再生芽具有高增殖活性区域，并由异质细胞群组成，这些细胞的前后位置和细胞周期参数各不相同。所提供的数据首次允许在环节动物再生的情况下定量细胞增殖。再生细胞表现出前所未有的高周期率和异常大的生长分数，使这种再生模型对于研究体内响应损伤的协调细胞周期进入特别有价值。
