Journal: bioRxiv
Article Title: Melanopsin regulates axonal translation underlying retinohypothalamic circuit assembly
doi: 10.64898/2026.04.21.716817
Figure Lengend Snippet: (A) Experimental workflow showing volumetric STORM imaging approach by ultrasectioning and serial reconstruction. (B) STORM analysis was performed in N=6 biological replicates per genotype (∼50K µm 3 volume each). Quantification shows significantly reduced synapse density Opn4-KO mice (red dots) compared to Opn4-Het controls (black dots). Het mean ± S.D. (0.03 ± 0.004); KO mean ± S.D. (0.023 ± 0.002); Cohen’s d 2.5; ***p<0.001 student’s t-test. (C) Representative 3D reconstructions of individual synapses immunolabeled for VGluT2 (cyan, presynaptic marker), Bassoon (magenta, active zone protein), and Homer1/2/3 (green, postsynaptic density marker) in Opn4 Cre/+ (Het, left panels) and Opn4 Cre/Cre (KO, right panels). Scale bars = 1 μm. (D) Quantitative analysis of synaptic protein distributions showing volume (top) and intensity (bottom) measurements for VGluT2, Bassoon, and Homer1 across N=6 Het (10,814 synapses, black) and N=6 KO (10,013 synapses, red) mice. Box-and-whisker plots with violin overlays show median, quartiles, and distribution within 1.5x the interquartile range. No significant differences observed in volume or intensity measurements between genotypes. (E) Engulfment of VGluT2 (magenta) and CTB-Alexa Fluor 488 puncta (green) by microglia (grey) in the SCN. Blue puncta in 3D renderings represent colocalized VGluT2/CTB punctae. Images show maximum intensity Z-projections (left) and 3D renderings (right) of wild-type (14.31 μm Z-stack) and Opn4-KO (12.96 μm Z-stack) tissue. (F) Superplots showing VGluT2 (top) and CTB-Alexa Fluor 488 (bottom) engulfment as a percentage of microglial volume. Small circles represent measurements from individual microglia, colored by source animal. N = 7 animals per group; Wild-type: 66 cells; Opn4-KO: 69 cells. Large circles represent individual animal means, connected to their respective cells by thin lines. Box-and-whisker plots show median, quartiles, and distribution within 1.5x the interquartile range. Statistical comparison was performed using a linear mixed model with genotype as a fixed effect and animal number as a random effect.
Article Snippet: The Opn4-Cre transgenic mouse line (JAX stock #035925) , Ribotag mice (#029977, B6J.129(Cg) Rpl22/SjJ) and Ai9(RCL-tdT) (B6.Cg- Gt(ROSA)26Sortm9(CAG-tdTomato)Hze /J) (JAX stock #007909) were obtained from Jackson.
Techniques: Imaging, Immunolabeling, Marker, Whisker Assay, Comparison