Mechanism of development of ionocytes rich in vacuolar-type H+-ATPase in the skin of zebrafish larvae
Mechanism of development of ionocytes rich in vacuolar-type H+-ATPase in the skin of zebrafish larvae
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DOI：
10.1016/j.ydbio.2009.02.026
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发表时间：
2009-05-01
影响因子：
2.7
通讯作者：
Hirose, Shigehisa
中科院分区：
文献类型：
--
作者：
Esaki, Masahiro;Hoshijima, Kazuyuki;Hirose, Shigehisa
富含线粒体的细胞（MRCs），或离子细胞，在水生物种中起着核心作用，通过主动摄取或排泄离子来维持体液离子稳态。自1932年在鳗鱼鳃中首次描述以来，广泛的形态学和生理学分析对离子细胞的结构和功能产生了重要的见解，但了解这些细胞的发育途径仍然是一个持续的挑战。我们以前成功地确定了一个关键的转录因子，Foxi 3a，在斑马鱼幼虫的数据库挖掘。在本研究中，我们分析了斑马鱼突变体，quadro（quo），缺乏foxi 1基因的表达，发现foxi 1是必不可少的MRC亚群的发展，丰富的液泡型H+-ATP酶（vH-MRC）。foxi 1作用于Delta-Notch信号传导的上游，其决定vH-MRC的零星分布并调节foxi 3a表达。通过功能获得和丧失测定以及细胞移植实验，我们进一步阐明了（1）foxi 3a的表达水平是通过foxi 3a及其下游基因gcm 2之间的正反馈环来维持的;（2）foxi 3a在vH-MRC的特化中具有细胞自主性功能。这些观察结果提供了一个更好的理解的分化和分布的vH-MRC亚型。(C)2009 Elsevier Inc. All rights reserved.
Mitochondrion-rich cells (MRCs), or ionocytes, play a central role in aquatic species, maintaining body fluid ionic homeostasis by actively taking up or excreting ions. Since their first description in 1932 in eel gills, extensive morphological and physiological analyses have yielded important insights into ionocyte structure and function, but understanding the developmental pathway specifying these cells remains an ongoing challenge. We previously succeeded in identifying a key transcription factor, Foxi3a, in zebrafish larvae by database mining. In the present study, we analyzed a zebrafish mutant, quadro (quo), deficient in foxi1 gene expression and found that foxi1 is essential for development of an MRC subpopulation rich in vacuolar-type H+-ATPase (vH-MRC). foxi1 acts upstream of Delta-Notch signaling that determines sporadic distribution of vH-MRC and regulates foxi3a expression. Through gain- and loss-of-function assays and cell transplantation experiments, we further clarified that (1) the expression level of foxi3a is maintained by a positive feedback loop between foxi3a and its downstream gene gcm2 and (2) Foxi3a functions cell-autonomously in the specification of vH-MRC. These observations provide a better understanding of the differentiation and distribution of the vH-MRC subtype. (C) 2009 Elsevier Inc. All rights reserved.