Abstract
Myotonia congenita is a human muscle disorder caused by mutations in CLCN1, which encodes human chloride channel 1 (CLCN1). Zebrafish is becoming an increasingly useful model for human diseases, including muscle disorders. In this study, we generated transgenic zebrafish expressing, under the control of a muscle specific promoter, human CLCN1 carrying mutations that have been identified in human patients suffering from myotonia congenita. We developed video analytic tools that are able to provide precise quantitative measurements of movement abnormalities in order to analyse the effect of these CLCN1 mutations on adult transgenic zebrafish swimming. Two new parameters for body-wave kinematics of swimming reveal changes in body curvature and tail offset in transgenic zebrafish expressing the disease-associated CLCN1 mutants, presumably due to their effect on muscle function. The capability of the developed video analytic tool to distinguish wild-type from transgenic zebrafish could provide a useful asset to screen for compounds that reverse the disease phenotype, and may be applicable to other movement disorders besides myotonia congenita.
Highlights
Myotonia congenita (MC) is an inherited muscle disorder that affects muscle relaxation
Constructs for human type 1 chloride channel or mutants linked to patients suffering from myotonia congenita (MC; hCLCN1I553F/H555N, hCLCN1L844F) under the controls of the muscle specific a-actin promoter (Figure 3) were used to produce stable transgenic zebrafish lines
Wild-type or mutated human CLCN1 (hCLCN1) and EGFP were separated by an internal ribosomal entry site (IRES; Figure 3D–F), allowing the independent expression of hCLCN1 and EGFP from the a-actin promoter
Summary
Myotonia congenita (MC) is an inherited muscle disorder that affects muscle relaxation. It is characterized by muscle stiffness after a voluntary contraction, which typically decreases with repetitive movement [1]. The clinical evaluations of the myotonia congenita include the expression of muscle stiffness or muscle weakness, muscle hypertrophy, percussion and electromyographic myotonia. CLCN1, a type 1 chloride channel which is expressed almost exclusively in skeletal muscle fibers, plays important roles for the physiological functions of skeletal muscles [3,4]. CLCN1 is a voltage-dependent ion channel, which is activated by depolarization. Two novel CLCN1 mutations have been found in Chinese and the physiological effects of the mutations were examined by expression of the channels in Xenopus oocytes. The larger effect was seen in the compound heterozygous situation combining the I553F and the H555N mutations [6]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call