Figure 5.

Follicle cell fates are disrupted in D-mef2 mutant egg chambers. Egg chambers were dissected from either Oregon-R (wt; A, C, and H) or D-mef2⁶⁵/D-mef2⁴²⁴ (mef2^−/−; B, D–G, and I) and hybridized with a digoxigenin-labeled dpp cDNA probe. Anterior is to the left. (A) Optical cross-sections of stage 6, 8, and 9 eggs (indicated). Expression in the anterior follicle cells at stage 8 is marked by an arrow. The strongly stained cells at stage 9 are marked by arrows that also denote the direction of follicle cell migration. (B) Markings are the same as in A except that stage 6 and 8 eggs are shown in surface views. (C) Surface view of a stage 10A egg. There is light staining in the NC-FC (slight blue haze over the nurse cells). The strongest staining is seen with the leading CMFC (arrows). (D and E) Dorsal and ventral surface views, respectively, of a stage 10A egg. The presumptive leading CMFC (stained for dpp) are misplaced. (F and G) Two additional samples of stage 10A eggs showing disruption of CMFC determination. (H) Optical cross-section of an early stage 11 egg. The leading CMFC has moved inward (arrows) along the boundary between the oocyte and the nurse cell complex. (I) Optical cross-section of a collapsing stage 11 egg. There is no distinct dpp staining.