Ectopic Expression of a Cecropin Transgene in the Human Malaria Vector MosquitoAnopheles gambiae(Diptera: Culicidae): Effects on Susceptibility toPlasmodium

Abstract

Genetically altering the disease vector status of insects using recombinant DNA technologies is being considered as an alternative to eradication efforts. Manipulating the endogenous immune response of mosquitoes such as the temporal and special expression of antimicrobial peptides like cecropin may result in a refractory phenotype. Using transgenic technology a unique pattern of expression of cecropin A (cecA) in Anopheles gambiae was created such that cecA was expressed beginning 24 h after a blood meal in the posterior midgut. Two independent lines of transgenic An. gambiae were created using a piggyBac gene vector containing the An. gambiae cecA cDNA under the regulatory control of the Aedes aegypti carboxypeptidase promoter. Infection with Plasmodium berghei resulted in a 60% reduction in the number of oocysts in transgenic mosquitoes compared with nontransgenic mosquitoes. Manipulating the innate immune system of mosquitoes can negatively affect their capacity to serve as hosts for the development of disease-causing microbes.

Immune signaling pathways regulating bacterial and malaria parasite infection of the mosquito Anopheles gambiae

“…This reaction could be due to the detected low constitutive activation of REL2-F, to pathway activation by Plasmodium, or both. A recent study has shown that ectopic overexpression of CEC1 drastically reduces susceptibility of mosquitoes to Plasmodium (33). Other REL2-regulated proteins that might explain the observed phenotype are Gambicin (GAM1), another AMP with antiparasitic activity in vitro (34), and LRIM1, a key antagonist of ookinete-tooocyst development (13).…”

An Active Transposable Element, Herves, From the African Malaria Mosquito Anopheles gambiaeSequence data from this article have been deposited with the EMBL/GenBank Data Libraries under accession no. AY462096.

“…gambiae remains problemhAT elements, hobo, Hermes, and Herves, provides a unique opportunity to examine the role that element sequences atic with only three successful transformations reported since 1987 (Miller et al 1987;Grossman et al 2001; within a transposable element family play in determining insertion site specificity. Our data show that Herves, Kim et al 2004). Furthermore, the difficult husbandry of An.…”

“…Moreira et al 2002;Kim et al 2004), a key remaining obstacle to the extension of this technology remobilization properties of Hermes, piggyBac, and Mos1 in somatic and germ-line nuclei were examined in transto the field remains the absence of gene vectors that can efficiently drive genes through mosquito populations.…”

Efficient ΦC31 integrase–mediated site-specific germline transformation of Anopheles gambiae

“…stephensi and Anopheles albimanus, transformation efficiency was much lower in An. gambiae and more technically challenging 22,23 . Since then, several modifications to the protocol have improved the efficiency considerably, as outlined in Lobo et al 24 .…”