Fig. 4: Restriction of synaptic Nrx-IV protein can account for motor neuron inhibition of miR-34.
a, b Presynaptic active zones marked by the T-bar constituent Brp (green) are surrounded by small punctate accumulations of Nrx-IV protein (magenta) in the terminal boutons of the M6/7NMJ (segment A2; Scale bar: 5  µm). b In miR-34 null animals, an identical staining and imaging protocol reveals a consistent and significant increase in the size and intensity of Nrx-IV puncta compared to control in a. c The difference in intensity between synaptic Nrx-IV signals is quantified (n = 6 NMJs per genotype; *p-value ≤ 0.05). d Alignment of the conserved MRE for Human (hsa) miR-34a within the 3’UTR of CNTNAP4 is shown in comparison to the corresponding MRE for Drosophila (dme) miR-34 in the Neurexin-IV (Nrx-IV) mRNA. e Motor neuron-specific competitive inhibition of miR-34 (n = 21) using OK6-GAL4 to express miR-34SP is compared to Nrx-IV overexpression (Nrx-IV OE) of under OK6-GAL4 (green bar; n = 19) or a muscle-specific DMef2-GAL4 (gray bar; n = 20) (**p-value ≤ 0.01; ***p-value ≤ 0.001) all relative controls n = 20. f OK6-GAL4 expression of miR-34SP induces a significant increase in type 1 bouton numbers per NMJ (green bar; n = 20) compared to Scramble-SP controls (white bar; n = 21); this phenotype is completely rescued by co-expression of UAS-Nrx-IVRNAi (gray bar; n = 20) (***p-value ≤ 0.001). Source data are provided as a Source Data file.
