Monitoring complete and incomplete abscission in the germ line stem cell lineage of Drosophila ovaries

In most species, cytokinesis is blocked in germ cells during at least some stage of their development. Abscission is difficult to assess directly in germ cells which are located in internal organs. Here, we described several indirect and direct methods to monitor the completion of abscission in Drosophila germ line cells. These methods are based on the observation that cells still connected by some cytoplasm share some degree of synchronization of their cell cycle. This synchrony can be detected on fixed tissue (Section 1.1), including using EdU incorporation to label S-phase (Section 1.2). Mitotic synchrony can also be observed using short-term live imaging (Section 1.3). Finally, we describe how the completion of abscission can be monitored using photoactivatable markers diffusing or not between two cells (Section 1.4).