Figure 7.

A proposed model for the TOR pathway and JH in regulating Vg synthesis responding to AAs stimulation. After feeding with normal diet, free AAs concentrations in the hemolymph are increased, the expression levels of the TOR pathway genes are elevated and S6K phosphorylation in the fat body is up-regulated. The activated TOR pathway works through some brain factors, like allatotropin, to induce JH biosynthesis in the corpora allata, and JH, in turn, activates expression of Vg gene in the fat body. Thus, the TOR pathway induces JH biosynthesis that, in turn, regulates AA-mediated vitellogenesis. JHAMT: juvenile hormone acid methyltransferase.