Fig. 3.

Mesenchymal loss of Sufu and Spop impairs progenitor growth and beta cell genesis. a, b Immunostaining for the SOX2⁺ stomach domain (St) and PDX1⁺ pancreatic domain (Panc) in E10.5 control a and Bapx1^Cre/+;Sufu^f/f;Spop^f/f mutants b embryos. c, d Immunostaining for E10.5 PDX1⁺ control c vs. mutant d pancreatic progenitors marked with thymidine analog, 5-bromo-2′-deoxyuridine (BrdU) 1 h after administration. e Assessment of the proportion of PDX1⁺ progenitors marked by BrdU as a measure of progenitor proliferation in mutants vs. controls (n = 4 samples per genotype). f, g Immunostaining for E13.5 NGN3⁺ control f vs. mutant g endocrine progenitors in the SOX9⁺ pancreatic progenitor pool. Arrows indicate non-specific staining. h Quantification of the proportion of NGN3⁺ committed endocrine progenitors out of the total NGN3⁺ and/or SOX9⁺ progenitor pool in mutants vs. controls (n = 3 control samples, n = 4 mutant samples). i, j Immunostaining for control i vs. mutant j INS⁺ cells labelled with BrdU after administration every 24 h during beta cell genesis (E14.5-E16.5). Arrows indicate representative BrdU⁺ labelled INS⁺ cells. k Assessment of INS⁺ cells labelled with BrdU after E14.5-E16.5 tracing as a measure of beta cell genesis in mutants vs. controls (n = 3 samples per genotype). l Diagram illustrating the temporal roles of mesenchymal Sufu and Spop throughout pancreatic development. Data are means ± SEM. n.s. denotes not significant, * denotes p < 0.05 by Student’s un-paired, two tailed t-test. Scale bars- 100 µm