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.