Fig. 7. Disrupting glutamate-mediated transmission at the NMJ reduces myogenic movements in the embryo. (A) Representative data for an embryo expressing grim panneuronally (elav-GAL4;UAS-grim) and an embryo homozygous for a mutation in an essential glutamate receptor subunit GluRIII. Unilateral waves of contraction occur in both, persisting for several hours. (B) Mean proportion of time each VL muscle spent in contraction 17-18 hours AEL is calculated for each genotype (n=4 for each genotype, with four or five 2-minute traces analysed for each embryo, error bars indicate s.e.m.). Embryos mutant for GluRIII show a lower frequency of contractions than embryos in which transmission at the NMJ is blocked presynaptically (through expression of TNT-G), and embryos lacking presynaptic terminals (through expression of grim).