Figure 1

Mll1 expression in mouse retina and its conditional knockout. (A) Diagram of mouse Mll1 coding sequence showing the positions of the catalytic SET domain and the LoxP sites flanking the nuclear localization signals encoded in exons 3-4²⁹. The binding sites for the in situ probe (red solid line) and two pairs of RT-PCR primers (arrows; sequences given in Supplementary Table S1) are indicated. (B) Quantitative RT-PCR analyses of Mll1 mRNA from the indicated postnatal ages using Primer Set 1, presented as fold expression relative to P0 samples, with error bars representing standard error of mean (SEM, n ≥ 3). *p < 0.05 based on one-way ANOVA with Tukey’s multiple comparisons. (C–I) in situ hybridization of Mll1 (red) with DAPI nuclear stain (blue) in retinal cross-sections of wild type (C57BL/6 J) mice at the indicated developmental time points. Note that the signal intensity increases in two inner retinal layers at P14 compared to earlier ages. NBL-neuroblast layer; GCL-ganglion cell layer; ONL-outer nuclear layer; INL-inner nuclear layer. Scale bar = 25um for Panels C, D, and E-I. (J) Quantitative RT-PCR analyses of Mll1 mRNA expression using Primer Set 2. The results are presented as fold expression relative to CreNeg littermate samples, with error bars representing SEM (n ≥ 3). *p < 0.05 compared to CreNeg by one-way ANOVA with Tukey’s multiple comparisons. (K,L) In situ hybridization with Mll1 probe on retinal cross-sections of 1-month old CreNeg and Mll1KO mice.