Figure 4.

Wrd is required for normal synaptic growth and morphology. a–c, Representative NMJs from muscle 4 in wild-type animals (a), wrd¹⁰⁴/Df(3R)DG4 mutants (b), and wrd¹⁰⁴ homozygotes rescued with neuronal expression of UAS wrd under elav Gal4 (c). Synapses are costained with antibodies to DVGLUT (green) and HRP (red). d, e, Enlarged images of boutons in wild-type animals (d) and wrd¹⁰⁴ homozygotes (e) highlighting increased size and rounded contours of boutons in wrd mutant. f, g, Quantification of bouton number and bouton area in segments A2 and A3 of muscle 4 1b innervation of third-instar larvae. Genotypes include wild type (elav Gal4/+), wrd¹⁰⁴/Df(3R)DG4 [elav Gal4/+; wrd¹⁰⁴/Df(3R)DG4), wrd¹⁰⁴ hz (elav Gal4/+; wrd¹⁰⁴/wrd¹⁰⁴)], and neuronally rescued wrd¹⁰⁴ hz (elav Gal4/UAS wrd; wrd¹⁰⁴/wrd¹⁰⁴). Bouton number and bouton area in wrd mutants are significantly different from wild-type animals; *p < 0.01 for bouton number in 4b; *p < 0.001 for bouton area in 4c. wrd¹⁰⁴/Df(3R)DG4 and wrd¹⁰⁴ hz are not significantly different for either bouton number or bouton area (p > 0.5). Neuronal expression of wrd cDNA rescues both bouton number and bouton area defects in wrd mutants. **p < 0.01 for bouton number in 4b; **p < 0.001 for bouton area in 4c. For both quantifications, wild type, n = 36; wrd¹⁰⁴/Df(3R)DG4, n = 32; wrd¹⁰⁴ hz, n = 36; and rescue, n = 16. Error bars represent SEM.