Fig. 10. Eya-driven matching of FCs and germline cells.

Illustration of Eya-controlled soma-germline coordination during Drosophila egg chamber morphogenesis. Eya in FCs cell-autonomously induces affinity for nurse cells, but not for the oocyte. This causes Eya-positive AFCs to spread out posteriorly to maximize their contact with nurse cells, which consequently displaces Eya-negative MBFCs onto the oocyte. Additionally, Eya in FCs non-autonomously controls effective germline affinity, such that Eya-positive FCs induce effective nurse cell affinity, while Eya-negative FCs induce effective oocyte affinity. As a result, the oocyte expands anteriorly during phase 2 to maximize its contact exclusively with Eya-negative FCs. Ultimately, these bilateral affinity dynamics result in a bidirectional matching dynamic that ensure robust matching of Eya-positive FCs with nurse cells and Eya-negative FCs with the oocyte. The established match represents the energetically preferred and therefore highly stable state.