Figure 3.

Presynaptically secreted Cow limits NMJ synaptic bouton number. A, Confocal images of the muscle 4 NMJ colabeled with anti-HRP (green) to mark the presynaptic membrane and anti-DLG (red) to mark the postsynaptic domain in the genetic background control (w¹¹¹⁸, left) and the cow null mutant (cow^GDP/Df, right). Synaptic bouton number is shown in a scatter plot, with mean ± SEM. B, Representative confocal NMJ images of motor neuron-targeted Gal4 driver control (vglut-Gal4/+; left), UAS-RNAi transgene control (UAS-cow-RNAi/+, middle) and cow RNAi knockdown (vglut>cow-RNAi, right). Satellite boutons (asterisks) are shown in the inset. Right, Synaptic bouton number is shown in a scatter plot, with mean ± SEM. C, Representative confocal NMJ images of muscle-targeted Gal4 driver control (24B-Gal4/+, left), UAS-RNAi transgene control (UAS-cow-RNAi/+, middle) and cow RNAi knockdown (24B>cow-RNAi, right). Synaptic bouton number is quantified to the right. The p values are shown for each statistical comparison.