Two isoforms of the early E74 gene, an Ets transcription factor homologue, are implicated in the ecdysteroid hierarchy governing vitellogenesis of the mosquito, Aedes aegypti
Autor(es): Sun Guoqiang,Zhu Jinsong,Li Chao,Tu Zhijian,Raikhel Alexander S
Resumo: In the anautogenous mosquito, Aedes aegypti, vitellogenesis is under the strict control of 20-hydroxyecdysone (20E), which is produced via a blood meal-activated hormonal cascade. Several genes of the ecdysteroid-regulatory hierarchy are conserved between vitellogenesis in mosquitoes and metamorphosis in Drosophila. We report characterization of two isoforms of the mosquito early E74 gene (AaE74), which have a common C-terminal Ets DNA-binding domain and unique N-termini. They exhibited a high level of identity to Drosophila E74 isoforms A and B and showed structural features typical for Ets transcription factors. Both mosquito E74 isoforms bound to an E74 consensus motif C/AGGAA. In the fat body and ovary, the transcript of AaE74 isoform homologous to Drosophila E74B was induced by a blood meal exhibiting its highest level coinciding with the peak of vitellogenesis. In contrast, the transcript of AaE74 isoform homologous to Drosophila E74A was activated at the termination of vitellogenesis. These findings suggest that AaE74A and AaE74B isoforms play different roles in regulation of vitellogenesis in mosquitoes.
Palavras-Chave: Early genes; 20-Hydroxyecdysone; Ets transcription factor; Vitellogenesis; Gene regulation
Imprenta: Molecular and Cellular Endocrinology, v. 190, n. 1-2, p. 147-157, 1990
Identificador do objeto digital: 10.1016/S0303-7207(01)00726-2
Descritores: Aedes aegypti - Cell ; Aedes aegypti - DNA ; Aedes aegypti - Genome ; Aedes aegypti - Molecular Structure ; Aedes aegypti - Pathogenesis ; Aedes aegypti - Proteins
Data de publicação: 2002
