Live Imaging of Drosophila Myoblast Fusion

摘要: There are 30 individual muscles per hemisegment of the Drosophila embryo. Formation these body wall depends on specification and fusion two myoblast cell types, founder cells (FCs) fusion-competent myoblasts (FCMs) (discussed in greater detail Chapter X). Each FC contains necessary information to direct formation a specific muscle. FCs can be identified by expression identity genes, such as transcriptional regulators even-skipped, apterous, slouch Kruppel. The combination genes expressed particular is thought regulate final morphology FCMs, contrast, naive cells. Upon an FC, FCMs become reprogrammed FC’s developmental program, witnessed each newly incorporated FCM nucleus expressing (1–5). Myoblast reiterative process; depending muscle, embryos arise from between 2 25 events (6). Fusion occurs during stages 12 15 [7.5–13 hrs after egg laying (AEL)]. FCs/myotubes arranged multiple layers prior process [Figure 1; (7)]. As commences, mesoderm with occupying both most external internal positions found (Figure 1A). germband retraction dorsal closure proceed 13 14, ventral move externally lie underneath epidermis central nervous system 1B–C). While some contact responsible for initial events, remaining located more internally must migrate find their partners. An appreciation arrangements movements essential analysis fusion. Figure 1 FC profile muscles Fusion does not start concurrently all 1D; For example, begins stage (7.5–9.5 AEL) DA1 but begin until (9.5–10.5 VA2 However, examined date, majority occur 14 (10.5–11.5 AEL; Figure 1D), making this particularly useful cellular biology underlying fusion. While genetic has revealed number required (reviewed x), precise function been hampered lack direct, assays. while many known encode actin cytoskeleton (8), impact cytoskeletal rearrangements were unclear. Furthermore, (7) have implicated critical role migration that remains analyzed. Lastly, site only implied localization proteins directly located. To address issues, we developed live imaging techniques further our understanding process. This chapter deals methodology considerations approach including collection mounting imaging, well itself processing presenting data.