cac overexpression partially rescues stj phenotypes. (A) Viability rescue of stj mutants by neuronal expression of cacEGFP. Percentages were calculated from the number of viable flies out of the expected number of flies based on a Mendelian ratio. n, number of flies counted from three to eight separate crosses. Genotypes scored: stj²/Df, C155-GAL4; stj¹/Df, UAScacEGFP, C155-GAL4; stj²/Df, UAScacEGFP, FRT42D^iso stj¹/Df-UAS-cacEGFP; MHC-GAL4/+, and FRT42D^iso stj²/Df-UAS-cacEGFP; MHC-GAL4/+. (B) ERGs recorded from C155-GAL4; stj¹/Df, UAScacEGFP and C155-GAL4; stj²/Df, UAScacEGFP flies have on–offs (arrowheads) similar to control ERGs. stj²/Df escapers lack on–offs. (C) Sample EJPs recorded in 1 mM Ca²⁺ at 1 Hz in C155-GAL4; UAScacEGFP/+, C155-GAL4; stj¹/Df, UAScacEGFP and stj²/Df. (D) Quantification of EJP amplitudes from control (39 ± 2 mV) C155-GAL4; UAScacEGFP/+ (44 ± 4 mV), stj¹/ Df (8 ± 2 mV), stj²/Df (11 ± 5 mV), C155-GAL4; stj¹/Df, UAScacEGFP (25 ± 5 mV) and C155-GAL4; stj²/Df, UAScacEGFP (21 ± 4 mV ). Error bars indicate SEM (student's t test; n.s., not significant; *, P < 0.05; **, P < 0.01). (E) Sample recordings of endogenous CPG activity at 36°C in 1.5 mM Ca²⁺ for stj¹/Df and C155-GAL4; stj¹/Df, UAS-cacEGFP. (F) Histogram of burst duration. Number of events analyzed from: control, n = 274 from eight animals; stj¹/Df, n = 38 from six larvae; and C155-GAL4; stj¹/Df, UAS-cacEGFP, n = 109 from four larvae (student's t test; stj¹/Df, P < 0.01).