title: Adhesion and Fusion of Muscle Cells Are Promoted by Filopodia.
abstract: Indirect flight muscles (IFMs) in Drosophila are generated during pupariation by fusion of hundreds of myoblasts with larval muscle templates (myotubes). Live observation of these muscles during the fusion process revealed multiple long actin-based protrusions that emanate from the myotube surface and require Enabled and IRSp53 for their generation and maintenance. Fusion is blocked when formation of these filopodia is compromised. While filopodia are not required for the signaling process underlying critical myoblast cell-fate changes prior to fusion, myotube-myoblast adhesion appears to be filopodia dependent. Without filopodia, close apposition between the cell membranes is not achieved, the cell-adhesion molecule Duf is not recruited to the myotube surface, and adhesion-dependent actin foci do not form. We therefore propose that the filopodia are necessary to prime the heterotypic adhesion process between the two cell types, possibly by recruiting the cell-adhesion molecule Sns to discrete patches on the myoblast cell surface.
authors: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Dagan
authors: D
authors: Segal
authors: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Nagaraju
authors: N
authors: Dhanyasi
authors: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel. Electronic address: eyal.schejter@weizmann.ac.il.
authors: Eyal D
authors: ED
authors: Schejter
authors: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel. Electronic address: benny.shilo@weizmann.ac.il.
authors: Ben-Zion
authors: BZ
authors: Shilo
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002454:Cell Differentiation; D002459:Cell Fusion; D002462:Cell Membrane / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D005260:Female; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000166:cytology* / Q000502:physiology; D032446:Myoblasts / Q000166:cytology* / Q000502:physiology; D011554:Pseudopodia / Q000502:physiology*
chemical_list: D000199:Actins; D015815:Cell Adhesion Molecules; D029721:Drosophila Proteins