Schejter Eyal D
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
Semin Cell Dev Biol. 2016 Dec;60:112-120. doi: 10.1016/j.semcdb.2016.07.016. Epub 2016 Jul 14.
Fusion of myoblasts gives rise to the large, multi-nucleated muscle fibers that power and support organism motion and form. The mechanisms underlying this prominent form of cell-cell fusion have been investigated by a variety of experimental approaches, in several model systems. The purpose of this review is to describe and discuss recent progress in the field, as well as point out issues currently unresolved and worthy of further investigation. Following a description of several new experimental settings employed in the study of myoblast fusion, a series of topics relevant to the current understanding of the process are presented. These pertain to elements of three major cellular machineries- cell-adhesion, the actin-based cytoskeleton and membrane-associated elements- all of which play key roles in mediating myoblast fusion. Among the issues raised are the diversity of functions ascribed to different adhesion proteins (e.g. external cell apposition and internal recruitment of cytoskeleton regulators); functional significance of fusion-associated actin structures; and discussion of alternative mechanisms employing single or multiple fusion pore formation as the basis for muscle cell fusion.
成肌细胞的融合产生了大型的、多核的肌纤维，这些肌纤维为生物体的运动和形态提供动力并给予支撑。在多个模型系统中，已经通过各种实验方法对这种显著的细胞间融合形式的潜在机制进行了研究。本综述的目的是描述和讨论该领域的最新进展，并指出目前尚未解决且值得进一步研究的问题。在描述了用于成肌细胞融合研究的几种新实验设置之后，提出了一系列与当前对该过程的理解相关的主题。这些主题涉及三种主要细胞机制的要素——细胞粘附、基于肌动蛋白的细胞骨架和膜相关元件——所有这些在介导成肌细胞融合中都起着关键作用。其中提出的问题包括赋予不同粘附蛋白的功能多样性（例如外部细胞附着和细胞骨架调节剂的内部募集）；融合相关肌动蛋白结构的功能意义；以及对采用单个或多个融合孔形成作为肌肉细胞融合基础的替代机制的讨论。
