ELECTRON MICROSCOPIC OBSERVATIONS OF MUSCLE DEDIFFERENTIATION IN REGENERATING AMBLYSTOMA LIMBS
ELECTRON MICROSCOPIC OBSERVATIONS OF MUSCLE DEDIFFERENTIATION IN REGENERATING AMBLYSTOMA LIMBS
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DOI：
10.1016/0012-1606(59)90018-1
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发表时间：
1959-01-01
影响因子：
2.7
通讯作者：
HAY, ED
中科院分区：
文献类型：
--
作者：
HAY, ED
两栖动物肢体骨骼肌纤维的精细结构的变化，因为他们去分化形成单核芽基细胞进行了描述。在截肢后的2至6天期间，所有分化的残肢组织去分化以产生一组芽基细胞，其在它们的精细结构上是相同的，并且通常是典型的胚胎细胞。在去分化过程中，肌核变圆，核仁突出，游离的胞质核糖核蛋白颗粒变多。细胞分化的细胞内和细胞外产物丢失，合胞体肌纤维分裂成单核细胞，单核细胞向顶端上皮迁移，与其他未分化的芽基细胞聚集。肌原纤维的消失始于肌丝的断裂。Z带的行为作为一个独特的extrafilamentary组件。肌丝和Z带最终都从细胞质中完全消失。新的细胞膜之间的个别肌肉单位似乎形成融合的小泡主要来自内质网。内质网和高尔基体分裂成紊乱的小泡，而线粒体几乎没有变化。这些优良的结构特征进行了讨论，在肢体再生的意义去分化。
The changes in the fine structure of skeletal muscle fibers of the amphibian limb as they dedifferentiate to form mononucleate blastema cells are described. In the 2 to 6 day period after amputation of the limb, all differentiated stump tissues dedifferentiate to produce a group of blastema cells which are identical in their fine structure and typical of embryonic cells in general. During dedifferentiation, muscle nuclei become rounded, nucleoli prominent and free cytoplasmic ribonucleoprotein granules become numerous. Intracellular and extracellular products of cell differentiation are lost and the syncytial muscle fibers break up into mononucleate cells which migrate toward the tip epithelium to aggregate with other un-differentiated blastema cells. The disappearance of myofibrils begins with fragmentation of myofilaments. The Z band behaves as a distinct extrafilamentous component. Both myofilaments and Z bands ultimately disappear completely from the cytoplasm. New cell membranes between the individual muscle units appear to form by fusion of small vesicles derived largely from the endoplasmic reticulum. The endoplasmic reticulum and Golgi apparatus fragment into disorganized vesicles, whereas mitochondria show little change. These fine structural features are discussed in relation to the significance of dedifferentiation in limb regeneration.