(A) Schematic diagram of B6 derived Chr.7 congenic regions in NOD-AI4 mouse strains. Marker positions are indicated in Mb based on genome assembly release GRCm38.p5 (33) (B) Flow cytometric gating strategy to enumerate AI4 DP thymocytes. Thymocytes from 5-week-old female NOD-AI4 (n=32), NOD.Ln82-AI4 (n=20) and NOD.Ln16-AI4 (n=14) were stained with CD4, CD8 and Vα8.3 specific antibodies. (C) Numbers of live (PI negative) CD4+CD8+ (DP) AI4 (Vα8.3+) thymocytes in the indicated strains. (D) Mean fluorescence intensity (MFI) of staining of DP thymocytes from the indicated strains by the Vα8.3-PE monoclonal antibody B21.14. All values represent mean±SEM of more than 3 independent experiments, statistical significance was determined by Log-rank (Mantel-Cox) t-test (ns p>0.05, ** p<0.001, **** p<0.00001).