Body Muscle-Cell Differentiation from Coelomic Stem Cells in Colonial Tunicates
Body Muscle-Cell Differentiation from Coelomic Stem Cells in Colonial Tunicates
复制标题
集落被囊动物体肌细胞与体腔干细胞的分化
DOI：
10.2108/zsj.24.542
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
K. Kawamura
中科院分区：
文献类型：
--
作者：
Y. Sugino;M. Matsumura;K. Kawamura
摘要利用超微结构观察了集群被囊类动物Symplegma reptans的体肌细胞分化。未分化的体腔细胞聚集在原始口管附近，并与表皮下的基膜结合。它们最初显示出成血细胞的特征，具有大的细胞核和突出的核仁，狭窄的细胞质充满多聚核糖体。然而，由于核的锯齿状轮廓的发展，它们很快就变得独特。当表皮的基底层发育成纤维细胞外基质（ECM）时，肌肉前体细胞具有深凹口核，并且在面对ECM的细胞质中具有粗和细丝。胶原纤维样结构出现在ECM中。肌丝的粗细比为1：2.5。致密体和斑块在口腔虹吸管穿孔前变得明显。这些结果表明，在S.在爬行动物中，括约肌细胞起源于未分化的成血细胞，并且它们的分化始于它们的细胞核中的形态学变化。表皮细胞和/或ECM可对肌细胞分化具有诱导作用。
Abstract Body muscle-cell differentiation was ultrastructurally examined in palleal buds of the colonial tunicate Symplegma reptans. Undifferentiated coelomic cells accumulate near the primordial oral siphon and associate with the basal lamina beneath the epidermis. They initially display the characteristics of hemoblast cells that have a large nucleus with a prominent nucleolus and narrow cytoplasm filled with polysomes. However, they soon become unique due to the development of an indented contour of the nucleus. When the basal lamina of the epidermis develops into the fibrous extracellular matrix (ECM), the muscle precursor cell has the deeply-notched nucleus, and thick and thin filaments in the cytoplasm facing the ECM. Collagen fibril-like structures appear in the ECM. Myofilaments are arranged with the ratio of thick to thin filaments being 1:2.5. Dense bodies and plaques become evident before the oral siphon is perforated. These results show that in S. reptans, the sphincter muscle cells arise from undifferentiated hemoblasts, and that their differentiation begins with a morphological change in their nuclei. Epidermal cells and/or the ECM may have an inductive effect on muscle cell differentiation.