A novel GATA factor transcriptionally represses yolk protein precursor genes in the mosquito Aedes aegypti via interaction with the CtBP corepressor

In anautogenous mosquitoes, vitellogenesis, the key event in egg maturation , requires a blood meal. Consequently, mosquitoes are vectors of many devas tating human diseases, An important adaptation for anautogenicity is the pr evitellogenic arrest (the state of arrest) preventing the activation of the yolk protein precursor (YPP) genes Vg and VCP prior to blood feeding. A no vel GATA factor (AaGATAr) that recognizes GATA binding motifs (WGATAR) in t he upstream region of the WP genes serves as a transcriptional repressor at the state of arrest. Importantly, AaGATAr can override the 20-hydroxyecdys one transactivation of WP genes, and its transcriptional repression involve s the recruitment of CtBP, one of the universal corepressors, AaGATAr trans cript is present only in the adult female fat body. Furthermore, in nuclear extracts of previtellogenic fat bodies with transcriptionally repressed YP P genes, there is a GATA binding protein forming a band,vith mobility simil ar to that of AaGATAr. The specific repression of YPP genes by AaGATAr in t he fat body of the female mosquito during the state of arrest represents an important molecular adaptation for anautogenicity.