Vitellogenic carboxypeptidase is a 53 kDa yolk protein produced by the fat body of the female mosquito, Aedes aegypti, in response to a blood meal. Its expression is sex-, stage- and tissue-specific and is identical to that of the major yolk protein, vitellogenin. The gene is intronless and two alleles have been cloned and sequenced, including more than 1.5 kb on both sides of the coding region. A capsite consensus recently identified as an arthropod initiator is present at the start site of transcription. Upstream of this capsite is a 16 bp imperfect palindrome repeated four times showing strong homology to defined hormone-response elements. In addition, a region that closely resembles the fat body enhancer and double sex binding site from the Drosophila yolk protein genes and several potential fat body-specific regulatory protein binding sites were found.