The Role of Estrogen-Related Receptor in Ionocyte Differentiation and Ionoregulation of Zebrafish (Danio rerio)
| Autor: | Chao-Yew Yang, 楊超宇 |
|---|---|
| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 Compared to terrestrial mammals, fish have to cope with more challenging osmotic and ionic gradients from aquatic environment with variant ion composition and pH values. Ionocytes, are highly energy-demanding and studied cells in research on fish ionoregulation, contribute an excellent model to study the regulatory mechanisms of ion transport. Estrogen-related receptors (ERRs) are members of orphan nuclear receptors and ubiquitously express in high-energy demanding organs for energy metabolism. Recently, ERRα was especially studied in mammalian kidney for sodium and potassium homeostasis through renin-angiotensin aldosterone system. In fact, skin/gill ionocytes in zebrafish are analogous to several types of the ion-transporting cells in mammalian kidney in terms of the expression and function of ion transporters. The purpose of the present study is to explore the role of zebrafish ERRs in ion regulatory mechanism by using molecular physiological approaches. zERRα and δ mRNA distributions showed “salt-and-pepper” patterns similar to ionocytes expression on the skin of zebrafish embryos so they would be the targets of the present study. The zERRα and δ mRNA expression were found to be stimulated by low pH ambience and also localized in HRC. However, in the loss-of-function experiments, the impairment of proton secretion only occurred when zERRα, but not zERRδ. Further, knockdown of zERRα decreased the cell density of H+-ATPase-rich cell (HRC) even with a concomitant increase of zebrafish glial cell missing 2 (zgcm2; a transcription factor specific for HRC differentiation) expression in zebreafish embryos. Hence, zERRα may play control zebrafish acid secretion function through regulation of zGCM2-mediated cell differentiation of HRC in the skin/gill. On the other hand, it will be an interesting and challenging issue to see if zERRδ, the other zERR member expressing in HRC, play an indirect role in acid secretion or is involved in other functions of zebrafish HRC. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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