Fig. 3: Rpap3 is required for proliferation in the small intestine.

a Schematic representation of the experimental setting: 8-week-old mice of the indicated genotype received two sequential injections of tamoxifen 24 h apart, and were analyzed 5 to 8 days after the first injection. 2 h before each sacrifice, BrdU was injected intraperitoneally to detect cells in S-phase (thin arrows). b Schematic representation of a crypt from the small intestine, with CBC stem cells (in green) sandwiched between Paneth cells (in brown) and progenitors forming the TA on top (purple). c Representative pictures of jejunum tissue sections stained with HE (top) or by IHC with anti-Ki67 antibody (bottom, Ki67 signal is brown) at indicated days after the first tamoxifen injection. Pink arrows point towards Paneth cells and black arrows towards CBC stem cells. Scale bar is shown in control HE panel. Each panel is representative of 8 to 12 animals analyzed in three independent experiments. Scale bar is identical for all panels and is 15 μm. d Representative pictures of jejunum taken from control (boxed in blue) and VilCreER^T2; Rpap3^flox/flox animals (boxed in red), stained by IHC with anti-BrdU antibodies (brown arrows). n = 3–6 animals/ time point from two independent experiments. Scale bar is shown in control panel and is 50 μm. e Graph shows mean number of BrdU⁺ cells/crypt in controls and VilCreER^T2; Rpap3^flox/flox animals at day 7. Each point represents the average number of BrdU⁺ cells calculated in n > 35 crypts from two different zones per animal (n = 3). Mean values with S.E.M are indicated for each experimental group. Unpaired two-tailed t test with Welch’s corrections (t = 11.66, df = 2) indicates significant difference between control and VilCreER^T2; Rpap3^flox/flox animals (p = 0.0073; n = 3). Source data are provided as a “Source Data file”.