Relish-mediated immune deficiency in the transgenic mosquito Aedes aegypti

doi:10.1073/pnas.0537347100

Relish-mediated immune deficiency in the transgenic mosquito Aedes aegypti

Department of Entomology, University of California, Riverside, CA 92521

Edited by John H. Law, University of Arizona, Tucson, AZ, and approved January 15, 2003 (received for review December 3, 2002)

Abstract

The lack of genetic means has been a serious limitation in studying mosquito immunity. We generated Relish-mediated immune deficiency (RMID) by transforming Aedes aegypti with the ΔRel transgene driven by the vitellogenin (Vg) promoter using the pBac[3xP3-EGFP, afm] vector. A stable transformed line had a single copy of the Vg-ΔRel transgene. The Vg-ΔRel transgene expression was highly activated by blood feeding, and transgenic mosquitoes were extremely susceptible to the infection by Gram-negative bacteria. This RMID phenotype was characterized by severely reduced postinfection levels of antimicrobial peptides genes, defensin and cecropin. Crossing the RMID line with the wild-type strain produced the same RMID phenotype, indicating its dominant nature, whereas crossing with the Vg-def transgenic line, in which Defensin A was activated by blood feeding, restored the immunity to Enterobacter cloacae.

Footnotes

↵ * S.W.S. and V.K. contributed equally to this work.
↵ † To whom correspondence should be addressed. E-mail: alexander.raikhel{at}ucr.edu.
This paper was submitted directly (Track II) to the PNAS office.
Abbreviations:

AMP,

antimicrobial peptide;

PBM,

postblood meal;

RMID,

Relish-mediated immune deficiency;

Vg,

vitellogenin;

EGFP,

enhanced GFP