Figure 2.

Histopathological and immunohistochemical characterization of adenomatous polyps in FAP pig lines. (a) Representative histological (PAS-AB) and immunohistochemical (Ki67 and IBA1 staining) images with corresponding statistical quantifications for APC^1311/+ (blue dots), APC^1311/+/TP53^+/- (green dots) and APC^1311/+/TP53^-/- (orange dots) groups. Scale bar = 100 or 200 μm. (b) Quantification of AB⁺ signal (blue: black arrow), semi-quantification of PAS⁺-AB⁺ signal (purple: red arrow), and quantification of Ki67⁺ and IBA1⁺ cells. For AB⁺ staining, each data point represents the mean of positive signal quantified from 10 regions containing aberrant crypts within a polyp at identical magnification using ImageJ. For PAS⁺AB⁺ staining, each data point represents the mean of positive signal semi-quantified from 10 regions containing aberrant crypts within a polyp at identical magnification using ImageJ and manual method to ensure accuracy. For immunohistochemical analyses, Ki67⁺ epithelial cells and IBA1⁺ macrophages (positive cells: brown staining) were quantified in crypt and stromal compartments. Each data point represents the mean number of positive cells determined by counting stained (brown) and unstained (blue) cells in 10 aberrant crypts and corresponding stromal regions per polyp using ViewPoint. Normal mucosa served as the reference control across all staining assays. One-way ANOVA followed by Tukey’s HSD post hoc test for normally distributed data with homogeneous variances. For non-normally distributed data, the Kruskal-Wallis H test followed by Dunn’s post hoc test was employed for pairwise comparisons. Data are presented as mean ± SEM (n = 4–10 pigs, 1–3 polyps selected for staining from each pig); ^* means P < 0.05, ^*** means P < 0.001.