Lethality of T287D CaMKII is rescued by tetracycline suppression of expression during development. Females of each GAL4 line were crossed to flies carrying UAS-tTA and tet0-T287D transgenes and grown with or without tetracycline in the larval medium. Adult progeny were counted, and the percentage viability and/or display of infantile characteristics of triple-transgenic progeny was recorded. All tetracycline-fed crosses completely rescued lethality or infantile characteristics, producing flies with wild type-like appearance. Data are shown for three different GAL4 lines, three different UAS-tTA insertions, and four different tet0-T287D insertions. −tc phenotype, Flies crossed without tc medium; +tc rescue, flies crossed with tc medium.