Ecdysone signaling regulates soldier-specific cuticular pigmentation in the termite Zootermopsis nevadensis

Termite caste differentiation requires hormonal regulation, but understanding of the role of ecdysone is limited. Here, we investigated the expression and function of ecdysone-related genes during soldier differentiation in the damp-wood termite Zootermopsis nevadensis. Ecdysone receptor gene (EcR) was highly expressed in the head just after the presoldier molt. Knockdown of EcR expression in the early presoldier period inhibited the molts into soldiers. However, knockdown in the middle period affected tyrosine metabolic gene expression and inhibited soldier-specific cuticular tanning. These results suggest that ecdysone activation is involved in soldier-specific cuticle formation.