|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Characterization of transepithelial potential oscillations in the Drosophila Malpighian tubule
Department of Biology and NSF Center for Biological Timing, PO Box 400328, University of Virginia, Charlottesville, VA 229044328, USA
(e-mail: eb5f{at}virginia.edu)
Accepted June 13, 2001
The Malpighian tubule of Drosophila melanogaster is a useful model system for studying the regulation of epithelial ion transport. In acutely isolated tubules, the transepithelial potential (TEP) undergoes large oscillations in amplitude with a period of approximately 30s. The TEP oscillations are diminished by reductions in the peritubular chloride concentration in a manner consistent with their being caused by fluctuations in chloride conductance. The oscillations are eliminated by pretreating tubules with the calcium chelator BAPTA-AM, although removal of peritubular calcium has no effect, suggesting that the oscillations are a result of either the release of calcium from intracellular stores or the entry of calcium from the tubule lumen. Transcripts encoding two calcium-release channels, the ryanodine receptor and the inositol trisphosphate receptor, are detectable in the tubule by reverse transcriptionpolymerase chain reaction. To identify the cell type responsible for the oscillations, tubules were treated with diuretic hormones known to alter calcium levels in each of the two cell types. Leucokinin-IV, which increases calcium levels in the stellate cells, suppressed the oscillations, whereas cardioacceleratory peptide 2b (CAP2b), which increases calcium levels in the principal cells, had no effect. These data are consistent with a model in which rhythmic changes in transepithelial chloride conductance, regulated by intracellular calcium levels in the stellate cells, cause the TEP oscillations.
Key words: Drosophila melanogaster, Malpighian tubule, calcium, transepithelial potential, leucokinin, CAP2b.
This article has been cited by other articles:
![]() |
N. M. Teets, M. A. Elnitsky, J. B. Benoit, G. Lopez-Martinez, D. L. Denlinger, and R. E. Lee Jr. Rapid cold-hardening in larvae of the Antarctic midge Belgica antarctica: cellular cold-sensing and a role for calcium Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2008; 294(6): R1938 - R1946. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. M. Coast, R. J. Nachman, and D. A. Schooley An antidiuretic peptide (Tenmo-ADFb) with kinin-like diuretic activity on Malpighian tubules of the house cricket, Acheta domesticus (L.) J. Exp. Biol., November 15, 2007; 210(22): 3979 - 3989. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. M. Blumenthal Modulation of tyramine signaling by osmolality in an insect secretory epithelium Am J Physiol Cell Physiol, November 1, 2005; 289(5): C1261 - C1267. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. O'Donnell and M. R. Rheault Ion-selective microelectrode analysis of salicylate transport by the Malpighian tubules and gut of Drosophila melanogaster J. Exp. Biol., January 1, 2005; 208(1): 93 - 104. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. P. Pollock, J. C. Radford, S. Pyne, G. Hasan, J. A. T. Dow, and S.-A. Davies norpA and itpr mutants reveal roles for phospholipase C and inositol (1,4,5)- trisphosphate receptor in Drosophila melanogaster renal function J. Exp. Biol., March 1, 2003; 206(5): 901 - 911. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. M. Blumenthal Regulation of chloride permeability by endogenously produced tyramine in the Drosophila Malpighian tubule Am J Physiol Cell Physiol, March 1, 2003; 284(3): C718 - C728. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. H. Hazel, J. P. Ianowski, R. J. Christensen, S. H. P. Maddrell, and M. J. O'Donnell Amino acids modulate ion transport and fluid secretion by insect Malpighian tubules J. Exp. Biol., January 1, 2003; 206(1): 79 - 91. [Abstract] [Full Text] [PDF] |
||||
![]() |
M.-J. Yu and K. W. Beyenbach Leucokinin activates Ca2+-dependent signal pathway in principal cells of Aedes aegypti Malpighian tubules Am J Physiol Renal Physiol, September 1, 2002; 283(3): F499 - F508. [Abstract] [Full Text] [PDF] |
||||