Some distinctive features of zebrafish myogenesis based on unexpected distributions of the muscle cytoskeletal proteins actin, myosin, desmin, alpha-actinin, troponin and titin.
The current myofibrillogenesis model is based mostly on in vitro cell cultures and on avian and mammalian embryos in situ. We followed the expression of actin, myosin, desmin, alpha-actinin, titin, and troponin using immunofluorescence microscopy of zebrafish (Danio rerio) embryos. We could see young mononucleated myoblasts with sharp striations. The striations were positive for all the sarcomeric proteins. Desmin distribution during muscle maturation changes from dispersed aggregates to a perinuclear concentration to striated afterwards. We could not observe desmin-positive, myofibrillar-proteins-negative cells, and we could not find any non-striated distribution of sarcomeric proteins, such as stress fiber-like structures. Some steps, like fusion before striation, seem to be different in the zebrafish when compared with the previously described myogenesis sequences.
Laboratório de Diferenciação Muscular e Citoesqueleto, Departamento de Histologia e Embriologia, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brazil. manoelluiscosta@ufrj.br
Manoel L
ML
Costa
Roberta C
RC
Escaleira
Viviane B
VB
Rodrigues
Muhamed
M
Manasfi
Claudia S
CS
Mermelstein
D000185:Actinin / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000818:Animals; D064211:Connectin; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003893:Desmin / Q000378:metabolism; D008856:Microscopy, Fluorescence; D024510:Muscle Development / Q000502:physiology*; D009124:Muscle Proteins / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D014336:Troponin / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology* / Q000378:metabolism*
D000199:Actins; D064211:Connectin; D003598:Cytoskeletal Proteins; D003893:Desmin; D009124:Muscle Proteins; D014336:Troponin; D000185:Actinin; D011494:Protein Kinases; D009218:Myosins