Up-regulation of muscle-specific transcription factors during embryonic somitogenesis of zebrafish (Danio rerio) by knock-down of myostatin-1.
Myostatin, a secreted growth and differentiation factor (GDF-8) belongs to transforming growth factor (TGF-beta) superfamily that plays as a negative regulator of skeletal muscle development and growth. Recently, myostatin has been isolated from fish; however, its role in muscle development and growth remains unknown. Here, we present the expression of myostatin during development and the effects of its knock-down on various genes such as muscle regulatory transcription factors (MRFs), muscle-specific proteins (MSP), and insulin-like growth factors (IGFs). The myostatin expression was found to be maternal as it starts in one-cell stage onward. The reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, and Southern and Northern blots demonstrated that the myostatin expression is not only restricted to skeletal muscle, but it expressed all the tested tissues. Expression of myostatin was effected by using antisense morpholinos resulted in significant phenotypic difference in stages 18 and 20 hours postfertilization (hpf). To confirm the specificity of myostatin morpholino, furthermore, a rescue experiment was conducted. The length as well as width of somites was increased with almost no gap in between the somites. In addition, it deserves to mention that this is a first animal model that shows changes in the size of the somites. Moreover, analyses of MRFs, MSP, and IGFs in the knock-down embryos by RT-PCR revealed the up-regulation of MyoD, Myogenin, and Mck transcription, whereas IGF-2 transcription showed mild response with no effect on IGF-1, Desmin, and Myf5. In situ hybridization showed that there was an increase in the number of somites from 3 to 4 at 13 and 22 hpf. Taken together, these data suggest that myostatin plays a major role during myogenesis, apart from inhibition of proliferation as well as differentiation.
Amali
Aseervatham Anusha
AA
Laboratory of Marine Molecular Biology and Biotechnology, Institute of Zoology, Academia Sinica, NanKang, Taipei, Taiwan.
Lin
Cliff Ji-Fan
CJ
Chen
Yi-Hsuan
YH
Wang
Wei-Lun
WL
Gong
Hong-Yi
HY
Lee
Chiou-Yueh
CY
Ko
Yen-Lin
YL
Lu
Jenn-Khan
JK
Her
Guor Mour
GM
Chen
Thomas T
TT
Wu
Jen-Leih
JL
D000818:Animals; D004625:Embryo, Nonmammalian / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D020868:Gene Silencing; D018482:Muscle, Skeletal / Q000196:embryology* / Q000378:metabolism; D017570:MyoD Protein / Q000235:genetics; D018006:Myogenic Regulatory Factors / Q000096:biosynthesis* / Q000235:genetics; D018008:Myogenin / Q000235:genetics; D055435:Myostatin; D012333:RNA, Messenger / Q000032:analysis; D019170:Somites / Q000166:cytology / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000502:physiology*; D015854:Up-Regulation; D015027:Zebrafish / Q000196:embryology*; D029961:Zebrafish Proteins
C525914:Mstnb protein, zebrafish; D017570:MyoD Protein; D018006:Myogenic Regulatory Factors; D018008:Myogenin; D055435:Myostatin; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D029961:Zebrafish Proteins