Pigmentation or melanization is an important physiological event in insects and is involved in cuticle tanning, wound healing and encapsulation as a defensive response. Dopachrome-conversion enzyme (DCE, Yellow) significantly accelerates the melanization of the chorion in mosquito eggs. In this study, we demonstrated functional importance of two ovary-specific yellow genes, AalY-g and AalY-g2, in the Asian tiger mosquito, Aedes albopictus. The transcripts of both genes were detected in the ovary of adult females only 48-72 h after blood feeding. RNAi for AalY-g or AalY-g2 had no effect on fecundity. However, the outermost colorless exochorion of the eggs was fragile and partially peeled off, and initial melanization of the endochorion was significantly delayed. Eggs from control females exhibited high desiccation resistance, whereas those from dsAalY-g- or dsAalY-g2-treated females were collapsed (50-80%) under the air-dry condition. Ultrastructural analysis revealed abnormal morphology of the endochorion and vitelline membrane in the AalY-g and AalY-g2-deficient eggshell. These results indicate that AalY-g and AalY-g2 are critical for integrity and desiccation resistance of the Ae. albopictus eggs. This work was supported by NRFs (NRF-2015R1A6A3A04060323).

• Mi Young Noh(Department of Applied Biology, Chonnam National University)
• Sung Hyun Kim(Department of Applied Biology, Chonnam National University)
• Seulgi Mun(Department of Applied Biology, Chonnam National University)
• Yasuyuki Arakane(Department of Applied Biology, Chonnam National University)