The role of PILMACs and of the genes bubbles and schwächling during muscle development in Drosophila melanogaster

在果蝇胚胎发育过程中，肌肉模式被建立，细胞-细胞融合导致多核肌管。融合能力成肌细胞(FCM)与方正细胞(FCS)/生长肌管融合。有了核糖激酶(进入ATP合成)，我们从方正细胞(FC)的测定和融合方面确定了一条新的肌肉发生的必要生化途径。观察融合的个别部位，建立了FuRMA，具有信号特性的瞬时细胞黏附结构。在这里，细胞黏附分子、信号分子、F-肌动蛋白及其调节因子确实积累。在超微结构水平上，单个融合部位的特征是位于相对膜上的一团囊泡，面积为1mm2，称为预融合复合体。重要的是，我们确定了FuRMAS的两个新成分：1)Tetraspanins作为候选的融合相关分子在相对的膜上聚集，以及2)一个EF Hand，可能是一个钙结合蛋白。作为一个可能的融合过程中膜弯曲的候选基因，我们发现了一个基因，它被预测编码一个C2结构域的蛋白，其中有两个假定的跨膜结构域。我们的中心目标是对这些新发现的聚变相关分子进行功能分析，并根据FuRMASs的拓扑结构将它们整合到与聚变相关的信号级联中。

During Drosophila embryogenesis, the muscle pattern is established and cell-cell fusion leads to multinucleated myotubes. Fusion-competent myoblasts (FCMs) fuse to founder cells (FCs)/growing myotubes. With Ribokinase (entry into ATP synthesis), we identified a new essential biochemical pathway for myogenesis with respect to Founder Cell (FC) determination and fusion. Looking at the individual site of fusion, FuRMASs are established, transient cell adhesion structures with signalling properties. Here, cell adhesion molecules, signalling molecules, F- actin, and its regulators do accumulate. At the ultrastructural level the individual fusion site is characterised by a cloud of vesicles at the opposing membranes over an area of 1mm2, named prefusion complex. Importantly, we identified two new components of the FuRMAS: 1) Tetraspanins as candidates for clustering of fusion-relevant molecules at the opposing membranes, and 2) Kosh, an EF hand, putatively Ca2+-binding protein. As a likely candidate for membrane bending during fusion, we identified a gene, which is predicted to encode a C2 domain protein with two putative transmembrane domains. Our central goals are the functional analysis of these newly identified fusion-relevant molecules and their integration into the fusion-relevant signalling cascades with respect to the topology of the FuRMASs.