Abstract
Muscle fibers are multinucleated cells that arise during embryogenesis through the fusion of mononucleated myoblasts. Myoblast fusion is a lifelong process that is crucial for the growth and regeneration of muscles. Understanding the molecular mechanism of myoblast fusion may open the way for novel therapies in muscle wasting and weakness. Recent reports in Drosophila and mammals have provided new mechanistic insights into myoblast fusion. In Drosophila, muscle formation occurs twice: during embryogenesis and metamorphosis. A fundamental feature is the formation of a cell–cell communication structure that brings the apposing membranes into close proximity and recruits possible fusogenic proteins. However, genetic studies suggest that myoblast fusion in Drosophila is not a uniform process. The complexity of the players involved in myoblast fusion can be modulated depending on the type of muscle that is formed. In this review, we introduce the different types of multinucleated muscles that form during Drosophila development and provide an overview in advances that have been made to understand the mechanism of myoblast fusion. Finally, we will discuss conceptual frameworks in cell–cell fusion in Drosophila and mammals.
Highlights
The movement of vertebrates is controlled by bundles of multinucleated skeletal muscle fibers that represent one-half of the body’s mass
The sing mRNA is expressed in founder cells and fusion-competent myoblasts and myoblasts are still able to adhere in the absence of Sing
Further proteins involved in signaling myoblast fusion: In addition to described signaling molecules and F-actin polymerization regulators, further proteins have been identified during Drosophila myoblast fusion
Summary
The movement of vertebrates is controlled by bundles of multinucleated skeletal muscle fibers that represent one-half of the body’s mass. At the site of cell–cell contact, a transient cell–cell communication structure forms that involves the ring-like expression of cell adhesion molecules of the immunoglobulin family in which an F-actin-rich center forms. The ring-like expression of cell adhesion molecules at the site of cell–cell contact triggers the formation of branched F-actin and the recruitment of electron-dense vesicles, which leads to the fusion of the myoblasts. This structure has been termed fusogenic synapse. We will give an overview of different studies that have been conducted during Drosophila embryonic and adult muscle development to unravel the mechanism of myoblast fusion. We will highlight common and different players directing myoblast fusion in different Drosophila muscle-types as well as in skeletal muscles
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
