Fig. 6. Model of bwk and shark interactions. (A) Shark expression is regulated by BWK function in the germline. Shark activity in the stretch cells is required for the proper anterior movement of the DA-forming cells as they move anteriorly. (B) bwk and shark interactions. Shark in the stretch cells regulates DA-cell movement, while Shark in the DA-forming cells regulates synthesis of the DA chorion. The suppression of bwk by SRC42A stretch-cell expression suggests that this protein may function alongside Shark to mediate DA-cell movement.