Expression of PAX6 transcripts and protein isoforms in the grafts and cultures of embryonic pancreatic epithelium.

<p>(A) qPCR analysis of paired (PD) and paired-less (ΔPD) PAX6 transcripts detected in epithelial grafts from WT or Id1+/−Id3−/− hosts 2 weeks post-transplant, as compared to those detected in epithelial clusters isolated from E14.5 pancreata. Bars represent mean ± SEM of triplicate values normalized to E-cadherin mRNA. Representative of n = 2 experiments. (B) Western blotting analysis of cytoplasmic and nuclear cell lysates from organ cultures of E14.5–15.5 pancreatic epithelium with M1 (EP+M1) or M2 (EP+M2) macrophages. Membranes were probed with an anti-PAX6 antibody or with an anti-β-actin antibody, as loading control. Representative of n = 3 experiments. (C–D) Tissue sections of E14–15.5 pancreatic grafts transplanted in BM-reconstituted Id1+/−Id3−/− mice, immuno-stained for PAX6 (green) and either E-cadherin or NCAM (red). Scale bars = 25 µm in C and 15 µm in D. (C) PAX6 immunoreactivity in ductal structures is observed in individual E-cadherin⁺ cells, within NCAM⁺ ductal domains and with a prevalent cytoplasmic pattern (arrowheads). (D) In contrast, PAX6 immunoreactivity in islet-like cell clusters shows a predominant nuclear localization.