|
type |
Journal Article |
authors |
Ferdig, M. T.; Li, J.; Severson, D. W.; Christensen, B. M. |
title |
Mosquito dopa decarboxylase cDNA characterization and blood-meal- induced ovarian expression |
journal |
Insect Mol Biol |
Activity |
4.1.1.28 |
ui |
96244737 |
year |
(1996) |
volume |
5 |
number |
2 |
pages |
119-26. |
| |
keywords |
Aedes/*enzymology/genetics |
abstract |
Dopa decarboxylase (DDC) functions in insect catecholamine biochemistry to produce materials essential for cross-linking reactions that result in tanning and/or melanization, include 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. |
last changed |
2002/11/12 16:17 |
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