QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online May 24, 2005
Journal of Experimental Biology 208, 2123-2134 (2005)
Published by The Company of Biologists 2005
doi: 10.1242/jeb.01620

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kopp, R. Articles by Pelster, B. Search for Related Content PubMed PubMed Citation Articles by Kopp, R. Articles by Pelster, B. Social Bookmarking                         What's this?

Cardiac performance in the zebrafish breakdance mutant

Renate Kopp, Thorsten Schwerte and Bernd Pelster^*

Institute of Zoology and Limnology, and Center for Molecular Biosciences, University of Innsbruck, Austria

^* Author for correspondence: (e-mail: bernd.pelster{at}uibk.ac.at)

Accepted 29 March 2005

In the Tübingen screen a breakdance mutant of zebrafish (bre) was described as an arrhythmia, in which the ventricle beats only with every second atrial contraction (2:1 rhythm). Surprisingly, a careful analysis of the effect of the breakdance mutation on cardiac performance of the zebrafish during development between 3 d.p.f. and 14 d.p.f revealed that homozygous bre mutants did not always show the 2:1 rhythm. Cardiac activity was continuously recorded for a period of 20 min in each larva, and during this period we observed that heart rate randomly switched between the 2:1 rhythm and a 1:1 rhythm. Furthermore, at 28°C and at 31°C the expression of the 2:1 rhythm decreased with development. At 31°C this was in part due to a significantly reduced survival rate of mutants beyond 4 d.p.f. Besides development, temperature had a marked effect on the expression of the 2:1 rhythm, and during the first days of development the expression of the 2:1 rhythm was significantly higher at elevated incubation temperatures. By contrast, in the 2:1 beating heart ventricular contraction rate was about 80 beats min^-1 throughout development irrespective of the temperature, and even in the 1:1 rhythm mutants showed a significant bradycardia at all three temperatures (25°C, 28°C or 31°C). Compared to wild-type animals, cardiac output was significantly lower in bre mutants. Pressure traces recorded in the ventricle of mutants revealed a prolonged relaxation phase, indicating that the second pacemaker current could not be conveyed to the ventricle (AV-block). This phenotype is comparable to the human Long QT Syndrome, an arrhythmia caused by a modification of an ion channel involved in cardiac repolarization. The bradycardia and the modified temperature sensitivity of heart rate suggested that the activity of the pacemaker cells was also affected by this mutation.

Key words: Breakdance mutation, cardiac activity, temperature, development, cardiac arrhythmia, zebrafish, Danio rerio

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				K. J. Rehm, A. L. Taylor, S. R. Pulver, and E. Marder Spectral Analyses Reveal the Presence of Adult-Like Activity in the Embryonic Stomatogastric Motor Patterns of the Lobster, Homarus americanus J Neurophysiol, June 1, 2008; 99(6): 3104 - 3122. [Abstract] [Full Text] [PDF]

				R. Arnaout, T. Ferrer, J. Huisken, K. Spitzer, D. Y. R. Stainier, M. Tristani-Firouzi, and N. C. Chi Zebrafish model for human long QT syndrome PNAS, July 3, 2007; 104(27): 11316 - 11321. [Abstract] [Full Text] [PDF]