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Mosquito dopa decarboxylase cDNA characterization and blood‐meal‐induced ovarian expression
Author(s) -
Ferdlg M. T.,
Li J.,
Severson D. W.,
Christensen B. M.
Publication year - 1996
Publication title -
insect molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.955
H-Index - 93
eISSN - 1365-2583
pISSN - 0962-1075
DOI - 10.1111/j.1365-2583.1996.tb00046.x
Subject(s) - biology , aedes aegypti , complementary dna , blood meal , open reading frame , drosophila melanogaster , population , genetics , microbiology and biotechnology , peptide sequence , gene , botany , zoology , demography , sociology , larva
Dopa decarboxylase (DDC) functions in insect cate‐cholamine biochemistry to produce materials essential for cross‐linking reactions that result in tanning and/or melanitation, including tanning of the mosquito egg chorion and encapsulation of parasites. We have cloned Ddc 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 Ddc 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 Ddc 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 Ddc 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.