title: Zebrafish ambra1a and ambra1b knockdown impairs skeletal muscle development.
abstract: The essential role of autophagy in muscle homeostasis has been clearly demonstrated by phenotype analysis of mice with muscle-specific inactivation of genes encoding autophagy-related proteins. Ambra1 is a key component of the Beclin 1 complex and, in zebrafish, it is encoded by two paralogous genes, ambra1a and ambra1b, both required for normal embryogenesis and larval development. In this study we focused on the function of Ambra1, a positive regulator of the autophagic process, during skeletal muscle development by means of morpholino (MO)-mediated knockdown and compared the phenotype of zebrafish Ambra1-depleted embryos with that of Ambra1gt/gt mouse embryos. Morphological analysis of zebrafish morphant embryos revealed that silencing of ambra1 impairs locomotor activity and muscle development, as well as myoD1 expression. Skeletal muscles in ATG-morphant embryos displayed severe histopathological changes and contained only small areas of organized myofibrils that were widely dispersed throughout the cell. Double knockdown of ambra1a and ambra1b resulted in a more severe phenotype whereas defects were much less evident in splice-morphants. The morphants phenotypes were effectively rescued by co-injection with human AMBRA1 mRNA. Together, these results indicate that ambra1a and ambra1b are required for the correct development and morphogenesis of skeletal muscle.
authors.affiliation: Department of Biology, University of Padova, Padova, Italy.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Skobo
authors.affiliation: Department of Biology, University of Padova, Padova, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Benato
authors.affiliation: Department of Molecular Medicine, University of Padova, Padova, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Grumati
authors.affiliation: Department of Biology, University of Padova, Padova, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Meneghetti
authors.affiliation: Department of Biology, University of Tor Vergata, Rome, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Cianfanelli
authors.affiliation: Department of Molecular Medicine, University of Padova, Padova, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Castagnaro
authors.affiliation: Department of Molecular Medicine, University of Padova, Padova, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Chrisam
authors.affiliation: Department of Biology, University of Tor Vergata, Rome, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Di Bartolomeo
authors.affiliation: Department of Molecular Medicine, University of Padova, Padova, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Bonaldo
authors.affiliation: Department of Biology, University of Tor Vergata, Rome, Italy; Department of Neuroscience, Istituto di Ricovero e Cura a Carattere Scientifico "Santa Lucia Foundation", Rome, Italy; Unit of Cell Stress and Survival, Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cecconi
authors.affiliation: Department of Biology, University of Padova, Padova, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Dalla Valle
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001718:Birefringence; D049109:Cell Proliferation; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000378:metabolism / Q000473:pathology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D055785:Gene Knockdown Techniques; D051379:Mice; D060172:Morpholinos / Q000494:pharmacology; D009068:Movement; D024510:Muscle Development / Q000235:genetics*; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000002:abnormalities / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism; D017570:MyoD Protein / Q000378:metabolism; D009218:Myosins / Q000378:metabolism; D051763:PAX7 Transcription Factor / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics*; D029961:Zebrafish Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C583440:Ambra1a protein, zebrafish; C583441:Ambra1b protein, zebrafish; D060172:Morpholinos; D017570:MyoD Protein; D051763:PAX7 Transcription Factor; D029961:Zebrafish Proteins; D009218:Myosins