Fig. 5.

Oogenesis in Drosophila. a Schematic diagram of the two ovaries of Drosophila that is made up of approximately 18 ovarioles. b Each of this ovarioles undergo 14 stages of development to from mature egg (st. 14) from germarium (st. 1). c The germarium contains SSCs and GSCs at the anterior end of ovariole. These GSCs divide asymmetrically to self-renew and to produce a daughter cell, cystoblast which then undergoes four rounds of asymmetric and incomplete mitoses to form germline cysts (16 cells) interconnected by ring canals. Only one from these cysts become oocyte which then develop into mature egg while the other 15 differentiate to become nurse cells. Meanwhile, the SSCs give rise to precursor follicle cells, and about 16 out of these precursor follicle cells, then become polar cells and stalk cells. The rest of the precursor follicle cells encysts cyst cells and become egg chamber. Created with BioRender.com