LSD1 substrates H3K4me1 and H3K4me2 peak at P2 and significantly decrease across retinal developmental time. Western blot analysis was conducted on C57BL/6J mouse retina samples at five different time points (P2, P7, P14, P21, and P36) in triplicate. Samples were probed with an anti-H3K4me1 (A) or anti-H3K4me2 antibody (E) (single band, expected size, 18 kDa), and an anti-H3 antibody (B, F) (single band, expected size, 18 kDa) served as a loading control. Quantification of results was achieved using densitometry, and H3K4me1/H3K4me2 levels were normalized to H3. A two-way ANOVA with Tukey's multiple comparison test was conducted between the mean expression level in all possible pair combinations. For H3K4me1, there is a statistically significant decrease between P2 and P14, P2 and P21, P7 and P14, and P7 and P21 (D). For H3K4me2, there is a statistically significant decrease between P2 and P14, P2 and P21, P2 and P36, P7 and P14, P7 and P21, and P7 and P36 (H). A full list of comparisons and P values are listed in Supplementary Table S2 and Supplementary Table S3. *P < 0.05, **P < 0.01, ***P < 0.001.