Calcium signaling in the developing Xenopus myotome
Calcium signaling in the developing Xenopus myotome
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DOI：
10.1006/dbio.1999.9387
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发表时间：
1999-09-15
影响因子：
2.7
通讯作者：
Spitzer, NC
中科院分区：
文献类型：
--
作者：
Ferrari, MB;Spitzer, NC
胚胎爪蟾肌细胞在培养分化过程中产生自发钙 (Ca2+) 瞬变。抑制这些瞬变会通过已确定的信号转导级联破坏肌原纤维组织和肌节的形成。由于瞬态经常发生在培养中的心肌细胞极化和迁移过程中，我们假设它们可能在组织形成过程中在体内发挥额外的作用。我们通过检查完整的非洲爪蟾近轴中胚层分化为成熟肌节时的 Ca2+ 动态来检验这一假设。我们发现，发育中的肌组细胞中发生 Ca2+ 瞬变，其特征与培养的肌细胞中的特征非常相似。肌节内产生的瞬态与体细胞发生以及肌细胞成熟相关。由于瞬态是由培养的心肌细胞的细胞内储存引起的，因此我们通过分别响应笼中 IP3 的光释放和咖啡因的灌注而引起 Ca2+ 升高，检查了完整肌节中 IP3 和兰尼碱受体的功能分布。与培养中一样，体内瞬变取决于兰尼碱受体 (RyR) 储存中的 Ca2+ 释放，并且在发育过程中阻断 RyR 会干扰体节成熟。 (C) 1999 年学术出版社。
Embryonic Xenopus myocytes generate spontaneous calcium (Ca2+) transients during differentiation in culture. Suppression of these transients disrupts myofibril organization and the formation of sarcomeres through an identified signal transduction cascade. Since transients often occur during myocyte polarization and migration in culture, we hypothesized they might play additional roles in vivo during tissue formation. We have tested this hypothesis by examining Ca2+ dynamics in the intact Xenopus paraxial mesoderm as it differentiates into the mature myotome. We find that Ca2+ transients occur in cells of the developing myotome with characteristics remarkably similar to those in cultured myocytes. Transients produced within the myotome are correlated with somitogenesis as well as myocyte maturation. Since transients arise from intracellular stores in cultured myocytes, we examined the functional distribution of both IP3 and ryanodine receptors in the intact myotome by eliciting Ca2+ elevations in response to photorelease of caged IP3 and superfusion of caffeine, respectively. As in culture, transients in vivo depend on Ca2+ release from ryanodine receptor (RyR) stores, and blocking RyR during development interferes with somite maturation. (C) 1999 Academic Press.