The expression of <i>TnBVank1</i> in prothoracic gland affects the E biosynthesis.

<p>(A) Ring gland includes the prothoracic gland (PG; yellow), the corpora allata (CA; orange) and the corpora cardiaca (CC; red). (B) The expression of the <i>TnBVank1</i> gene is driven in the different ring gland compartments, highlighted in green, by three <i>Gal4</i> drivers. <i>P0206-Gal4>TnBVank1</i>, expressed in PG and CA, causes the developmental arrest at the last larval stage; <i>aug21-Gal4>TnBVank1</i> (CA) does not induce any developmental defects; <i>phm-Gal4>TnBVank1</i> (PG) blocks the transition from larval to pupal stage. (C) Total 20E titer in five larvae of <i>UASp-TnBVank1</i> stock (white bars), <i>phm-Gal4/TM6B</i> (grey bars) and <i>phm-Gal4>TnBVank1</i> (black bars), at different time (hours AED). In the control stocks <i>UASp-TnBVank1</i> and <i>phm-Gal4/TM6B</i>, the 20E peak which induces the pupariation is present at 120 h AED. Instead, this peak is absent in <i>phm>TnBVank1</i> larvae at 120 h AED and during the extended larval life. Error bars represent s.d.; *** = p<0.0001 versus controls (<i>UASp-TnBVank1</i> and <i>phm-Gal4/TM6B</i>). The mean values of total 20E at 120 h AED of different genotype larvae are shown above the bars. (D) Feeding <i>TnBVank1</i> larvae with medium supplemented with 20E induces the pupariation (red), while <i>TnBVank1</i> larvae fed with medium containing ethanol (EtOH) do not reach the pupal stage (green). Values are the mean ± s.d. of three independent experiments. The <i>yw;phm-Gal4</i> larvae serve as background control (blue). Immunostaining with anti-Dib in <i>yw;phm-Gal4</i> (E) and <i>TnBVank1</i> (F) PG reveals that the expression of Dib is strongly reduced in all <i>TnBVank1</i> PGs analyzed. Panels E,F are at the same magnification and the reference scale bar is 25 µm indicated in E.