Figure 4
Schematic drawing of relationship between temperature and photoperiod and diapause induction via a unique peptidergic signaling system, DH signaling.
Progeny diapause is determined by environmental temperature and photoperiod during maternal embryonic development. Silkworms incubated under 25DD and 20LL conditions lay pigmented diapause eggs. In contrast, incubation at 15DD and 20DD causes the resultant moths to lay non-diapause eggs. BmTRPA1 acts as a thermosensitive channel that affects diapause induction. We hypothesize that the links in the pathway from reception of environmental signals to expression of the diapause phenotype include storage, integration and later translation of information into DH signaling in the form of diapause induction. Non-diapause eggs complete their embryogenesis approximately 9 d after oviposition at 25 °C. In contrast, diapause eggs remain in the diapause stage.
