PUBLICATION

The Zebrafish frozen Mutant Is a Model for Human Myopathy Associated with Mutation of the Unconventional Myosin MYO18B

Authors
Gurung, R., Ono, Y., Baxendale, S., Lee, S.L., Moore, S., Calvert, M., Ingham, P.W.
ID
ZDB-PUB-161124-8
Date
2017
Source
Genetics   205(2): 725-735 (Journal)
Registered Authors
Baxendale, Sarah, Ingham, Philip, Lee, Samantha Lin Chiou, Ono, Yosuke
Keywords
MYO18B, fast-twitch muscle, frozen, nemaline myopathy, zebrafish
MeSH Terms
  • Animals
  • Muscle Fibers, Fast-Twitch/cytology
  • Muscle Fibers, Fast-Twitch/metabolism
  • Myopathies, Nemaline/genetics*
  • Myosins/genetics*
  • Myosins/metabolism
  • Zebrafish/genetics*
  • Zebrafish/growth & development
  • Zebrafish/metabolism
  • Zebrafish Proteins/genetics*
  • Zebrafish Proteins/metabolism
PubMed
27879346 Full text @ Genetics
Abstract
MYOSIN 18B is an unconventional myosin that has been implicated in tumour progression in humans. In addition, loss-of-function mutations of the MYO18B gene have recently been identified in several patients exhibiting symptoms of nemaline myopathy. In mouse, mutation of Myo18B results in early developmental arrest associated with cardiomyopathy, precluding analysis of its effects on skeletal muscle development. The zebrafish, frozen (fro) mutant was identified as one of a group of immotile mutants in the 1996 Tübingen genetic screen. Mutant embryos display a loss of birefringency in their skeletal muscle, indicative of disrupted sarcomeric organization. Using meiotic mapping, we localized the fro locus to the previously un-annotated zebrafish myo18b gene, the product of which shares close to 50% identity with its human orthologue. Transcription of myo18b is restricted to fast-twitch myocytes in the zebrafish embryo; consistent with this, fro mutant embryos exhibit defects specifically in their fast-twitch skeletal muscles. We show that sarcomeric assembly is blocked at an early stage in fro mutants, leading to the disorganised accumulation of actin, myosin and α-actinin and a complete loss of myofibrillar organization in fast-twitch muscles.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping