Mosquito dopa decarboxylase cDNA characterization and blood-meal-induced ovarian expression

Autor(es): Ferdig, MT; Li, J; Severson, DW; Christensen, BM


Resumo: Dopa decarboxylase (DDC) functions in insect catecholamine Biochemistry to produce materials essential for cross-linking reactions that result in tanning and/or melanization, including tanning of the mosquito egg chorion and encapsulation of parasites. We have cloned Dde from the mosquito, Aedes aegypti, and studied its expression in response to blood-feeding, which initiates events necessary for egg maturation in mosquitoes. The Ae. aegypti Dde cDNA was isolated via heterologous screening using a clone from Drosophila melanogaster. A resulting 1.87 kilobase (kb) clone was Sequenced to reveal an open reading frame of 1464 bp, as well as 5'- and 3'-untranslated segments, The inferred amino acid Sequence of this clone shares 81% identity with the published Drosophila Dde cDNA, including complete identity with twenty-four contiguous amino acids encompassing the pyridoxal-5-phosphate cofactor binding domain, Analysis of an F2 intercross population derived from a parental cross between two Ae. aegypti strains (Hamburg and Moyo-In-Dry) allowed us to map Dde to a locus on linkage group 2. Expression studies demonstrated the presence of a 2.1 kb message, the majority of which occurs in the ovaries where Ddc-specific mRNA is up-regulated in response to ingestion of a blood meal, The potential for egg-tanning in anautogenous mosquitoes as a model for understanding specific genetic events in the regulation of catecholamine metabolism is addressed.


Palavras-Chave: Aedes Aegypti; Dopa Decarboxylase; Gene Expression; Ovary Development


Imprenta: Insect Molecular Biology, v. 5, n. 2, p. 119-126, 1996


Identificador do objeto digital: 10.1111/j.1365-2583.1996.tb00046.x


Descritores: Aedes aegypti - DNA ; Aedes aegypti - RNA


Data de publicação: 1996