Fig. 1. The da loss-of-function phenotype. (A) Diagram of the anterior end of an ovariole, including terminal filament (tf), subdivided germarium (with regions indicated), and early follicles of the vitellarium. Somatic cells (gray), polar cells (purple) and stalks are indicated. Wild-type (B,F), dalyh/da2 (C), dalyh/dalyh (D,E,G,H) ovaries were costained for Hts (Hu li tai shao; green) and Vasa (magenta). At eclosion most da null ovarioles (C,D) have no distinct interfollicular stalks; in 10% of ovarioles (E), the posteriormost follicle is separated by a stalk, but always at the expense of the follicular epithelium of the second germline cyst produced. (G) Older da mutant ovaries, despite extensive defects within the vitellarium, have typical germarium morphology. Interfollicular stalks do not form, even when sufficient somatic cells accumulate (arrow) adjacent to follicles with multiple cysts. (H) In more extreme examples, regions 2b and 3 are lost within the compound follicles that constitute the remainder of the ovariole. (I) A typical DAPI-stained dalyh ovariole. Images B-E are at the same scale, as are images F-H.
