| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan
2 Ocean Research Institute, University of Tokyo, Nakano, Tokyo, Japan
* To whom correspondence should be addressed. E-mail: shirose{at}bio.titech.ac.jp.
Supporting evidence for the contractile nature of fish branchial pillar cells was provided by demonstrating the presence of actin fibers and a novel four-and-a-half LIM (FHL)protein whose expression is specific for contractile tissues and sensitive to the tension applied to the pillar cell. When eel gill sections were stained with rhodamine-phalloidin, a selective fluorescent probe for fibrous actin, a strong bundle-like staining was observed around collagen columns in pillar cells suggesting the presence of abundant actin fibers. A cDNA clone encoding a novel member of the actin-binding FHL family, FHL5, was isolated from a subtracted cDNA library of eel gill. Northern analysis revealed that FHL5 mRNA is highly expressed only in gills, heart, and skeletal muscle. In gills, FHL5 was found to be confined to pillar cells by immunohistochemistry. Confocal fluorescence microscopy showed that FHL5 is present in both cytosol and nucleus; within the cytosol, a large portion of FHL5 is colocalized with the phalloidin-positive actin bundles. Furthermore, transfection of myogenic C2C12 cells with FHL5 cDNA demonstrated, in addition to its interaction with actin stress fibers, a nuclear shuttling activity of FHL5. The mRNA and protein levels were found to be elevated on 1) transfer of eels from seawater to freshwater, 2) volume expansion by infusion of isotonic dextran-saline, and 3) constriction of gill vasculature by bolus injection of endothelin-1. These results suggest contractile nature of pillar cells and a role of FHL5 in maintaining the integrity and regulating the dynamics of pillar cells.
This article has been cited by other articles:
|
|
 |
|
  M. G. Jonz and C. A. Nurse New developments on gill innervation: insights from a model vertebrate J. Exp. Biol., August 1, 2008; 211(15): 2371 - 2378. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. H. Evans Teleost fish osmoregulation: what have we learned since August Krogh, Homer Smith, and Ancel Keys Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2008; 295(2): R704 - R713. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Kato, K. Nakamura, H. Kudo, Y. H. Tran, Y. Yamamoto, H. Doi, and S. Hirose Characterization of the Column and Autocellular Junctions That Define the Vasculature of Gill Lamellae J. Histochem. Cytochem., September 1, 2007; 55(9): 941 - 953. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Kudo, A. Kato, and S. Hirose Fluorescence Visualization of Branchial Collagen Columns Embraced by Pillar Cells J. Histochem. Cytochem., January 1, 2007; 55(1): 57 - 62. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K.-O. Stenslokken, L. Sundin, and G. E. Nilsson Endothelin receptors in teleost fishes: cardiovascular effects and branchial distribution Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2006; 290(3): R852 - R860. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
