Insulin pathway and juvenile hormone regulate vitellogenesis in the red flour beetle, Tribolium Castaneum.

Nutrition and juvenile hormone (JH) are the two most important factors that regulate vitellogenesis in insects, but their cross-talk remains unknown. Here we report that nutritional signals are transduced through insulin pathway and work together with JH to regulate vitellogenesis in the red flour beetle, Tribolium Castaneum. After adult emergence, female beetles begin to feed, synthesize JH and express vitellogenin genes by day 3. Either starvation or decrease in JH levels by RNAi-aided suppression in expression of JH acid methyl transferase gene blocked vitellogenesis. Moreover, vitellogenesis was rescued by application of JH or its analog suggesting that both nutrition and JH are necessary for vitellogenesis in this insect.