Endocytosis in Drosophila: Progress, possibilities, prognostications

By many outside the field, endocytosis is often perceived as a "house-keepi ng" function performed via identical mechanisms in yeast and man. Recent di scoveries have done much to reduce this misperception. (1) Endocytosis occu rs via different mechanisms and different pathways in different cellular co ntexts. (2) Molecular mechanisms that regulate homologous pathways in unice llular and multicellular organisms show considerable variance. (3) Temporal ly controlled endocytosis of specific regulatory molecules underlies severa l important and intricate biological processes including synapse formation, synaptic plasticity, cell fate determination, and morphogen gradient forma tion. Interactions between endocytosis and cytoskeletal and signaling pathw ays have been particularly revealing. In this intellectual context, Drosoph ila has become invaluable as a metazoan genetic model in which to understan d the many faces of endocytosis. This review discusses two aspects of work in Drosophila: (a) its contributions toward understanding fundamental mecha nisms that underlie the operation of endocytic pathways; (b) how analyses i n Drosophila provide insights into varied biological processes regulated by endocytosis. In addition, while offering our commentary on merits and limi tations of Drosophila work, we speculate on likely areas for contributions and future research on endocytosis in Drosophila. (C) 2001 Academic Press.