Fig. 3. broad-inhibiting elements are expressed in unexpected regions.

(a) A probe designed to a common region of both pnt transcripts, P1 and P2, reveals their combined expression patterns at S8 in D. melanogaster. P1 is expressed in posterior follicle cells and P2 is expressed at the anterior of the oocyte (Morimoto et al. 1996). At S10 (not shown), the P2 expression pattern refines into a T shape across the dorsal midline (similar to the D. melanogaster aos image shown in f). (b) In late D. melanogaster stages, the common-region probe reveals pnt P1 expression persisting in the posterior follicle cells while P1 and P2 expression in the anterior splits into two dorsolateral patches of follicle cells. (c) In S. lebanonensis, a probe to the predicted common region shows that early-stage egg chambers express pnt only in the posterior follicle cells. (d) In late stages, S. lebanonensis pnt is maintained in posterior follicle cells and now also appears in a dorsolateral band of 4–5 rows of anterior follicle cells. (e) Quantitation of S. lebanonensis pnt patterning; N > 10 for each stage category. (f) D. melanogaster aos expression is limited to a small peak above the oocyte nucleus starting at S11. (g) S. lebanonensis aos is expressed in a dorsolateral band of follicle cells. (h) Quantitation of S. lebanonensis aos patterning; N > 10 for each stage category.