A GENETICALLY-ENGINEERED MOSQUITOCIDAL CYANOBACTERIUM

Larvae of the mosquito Aedes aegypti ingested, and developed into adul ts, on a diet of 10 of 14 different species of cyanobacteria including Agmenellum quadruplicatum PR-6 (= Synechococcus PCC7002). Mosquito la rvae ingested and grew on cells of PR-6 adapted to growth in the absen ce of NaCl. The cryIVD gene of Bacillus thuringiensis var. israelensis was cloned into a PR-6 expression vector to form pAQRM56, which was t ransformed into PR-6. Expression of the CryIVD protein in PR-6 was dem onstrated by immunocytochemistry and larvicidal activity. Immunogold l abelling indicated production of an electron-dense material among the thylakoid membranes of PR-6. Cells of PR-6 carrying pAQRM56 were toxic to the larvae of A. aeqypti whereas control cells were not. Growth of PR-6 cells carrying pAQRM56 was slower than the growth of control cel ls and these cells were also larger.