Overexpression of Myostatin2 in zebrafish reduces the expression of dystrophin associated protein complex (DAPC) which leads to muscle dystrophy.
Myostatin, a member of the TGF-beta superfamily, is a potent negative regulator of skeletal muscle and growth. Previously, we reported Mstn1 from zebrafish and studied its influence on muscle development. In this study, we identified another form of Myostatin protein which is referred to as Mstn2. The size of Mstn2 cDNA is 1342 bp with 109 and 132 bp of 5' and 3'-untranslated regions (UTRs), respectively. The coding region is 1101 bp encoding 367 amino acids. The identity between zebrafish Mstn1 and 2 is 66%. The phylogenetic tree revealed that the Mstn2 is an ancestral form of Mstn1. To study the functional aspects, we overexpressed mstn2 and noticed that embryos became less active and the juveniles with bent and curved phenotypes when compared to the control. The RT-PCR and in situ hybridization showed concurrent reduction of dystrophin associated protein complex (DAPC). In cryosection and in situ hybridization, we observed the disintegration of somites, lack of transverse myoseptum and loss of muscle integrity due to the failure of muscle attachment in mstn2 overexpressed embryos. Immunohistochemistry and western blot showed that there was a reduction of dystrophin, dystroglycan and sarcoglycan at translational level in overexpressed embryos. Taken together, these results indicate the suitability of zebrafish as an excellent animal model and our data provide the first in vivo evidence of muscle attachment failure by the overexpression of mstn2 and it leads to muscle loss which results in muscle dystrophy that may contribute to Duchenne syndrome and other muscle related diseases.
Amali
Aseervatham Anusha
AA
Laboratory of Marine Molecular Biology and Biotechnology, 301, Institute of Cellular and Organismic Biology, Academia Sinica, 128, Academia Road, Section 2, NanKang, Taipei 11529, Taiwan.
Lin
Cliff Ji-Fan
CJ
Chen
Yi-Hsuan
YH
Wang
Wei-Lun
WL
Gong
Hong-Yi
HY
Rekha
Ravikumar Deepa
RD
Lu
Jenn-Kan
JK
Chen
Thomas T
TT
Wu
Jen-Leih
JL
D000818:Animals; D015536:Down-Regulation / Q000235:genetics*; D049030:Dystroglycans / Q000235:genetics; D016189:Dystrophin / Q000235:genetics*; D049028:Dystrophin-Associated Protein Complex / Q000235:genetics*; D004625:Embryo, Nonmammalian; D018482:Muscle, Skeletal / Q000503:physiopathology; D009137:Muscular Dystrophy, Animal / Q000209:etiology*; D055435:Myostatin / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D049031:Sarcoglycans / Q000235:genetics; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000502:physiology*
D016189:Dystrophin; D049028:Dystrophin-Associated Protein Complex; C525914:Mstnb protein, zebrafish; D055435:Myostatin; D049031:Sarcoglycans; D029961:Zebrafish Proteins; D049030:Dystroglycans