GERMLINE CYST FORMATION IN DROSOPHILA

In a wide variety of organisms, gametes develop within clusters of int erconnected germline cells called cysts. Four major principles guide t he construction of most cysts: synchronous division, a maximally branc hed pattern of interconnection between cells, specific changes in cyst geometry, and cyst polarization. The fusome is a germline-specific or ganelle that is associated with cyst formation in many insects and is likely to play an essential role in these processes. This review exami nes the cellular and molecular processes that underlie fusome formatio n and cyst initiation, construction, and polarization in Drosophila me lanogaster. The studies described here highlight the importance of cys t formation to the subsequent development of functional gametes.