Figure 1

Protein starvation upregulates Egr levels in testicular muscles. (A–C’ and E–G’) Testes of egr-GFP^v (A–C’) and egr-GFP^BL (E–G’) immunostained for GFP (green in A–C and E–G, and white in A’–C’ and E’–G’). Nuclei are labeled by Hoechst 33342 (red). Flies were either raised on standard protein-rich food (fed) or protein-restrict diet (starved) for 18 days. Egr-GFP signals were detected in testicular muscles from starved males (B,C,F,G), but not from fed males (A,E). The grade of Egr-GFP expression was classified to moderate (B,B’ and F,F’) or high (C,C’ and G,G’) based on the signal intensity and the size of GFP-positive area (see “Methods”). Scale bars 50 μm. (D,H) Percentages of testes with detectable Egr-GFP expression in the testicular muscles. (D) The percentages of testes expressing Egr-GFP in smooth muscles were increasing over time in males starved from 9 to 21 days. (H) GFP accumulation in smooth muscles was detected in almost all testes from egr-GFP^BL males starved for 18 days. GFP was not detected in the testicular muscles of males fed for 18 days.