Depletion of BgDl and BgSer did not impede stalk formation. (a) mRNA expression levels of BgN, BgDl and BgSer in ovaries from 5-day-old dsBgDl + dsBgSer-treated females. Data represent values normalized against the control (reference value = 1) (n = 3). (b–e) Detail of the stalk structure connecting the basal (BOF) and the sub-basal (sBOF) ovarian follicles in 5-day-old dsMock-treated (b), dsBgDl-treated (c), dsBgSer-treated (d) and dsBgDl + dsBgSer-treated (e) females. The stalk was always formed in treated females and sometimes it is even longer than in dsMock-treated females. The F-actin microfilaments were stained with phalloidin-TRITC (green), and DNA with DAPI (blue). The posterior pole of the basal follicle is oriented towards the bottom left. Scale bars, 50 µm.