QTL mapping of Rbcstor1 and Rbcstor2. (A) B6 mice were crossed with FVB mice to generate an F1 generation. F1 mice were then interbred to generate an F2 generation. A total of 156 F2 mice were analyzed for their genetic backgrounds (SNP-based genotyping) and tested for RBC storage biology both by determining posttransfusion recoveries (depicted in panel B) and by high-resolution metabolomics (detailed in Table 1). (B) Twenty-four–hour recovery of stored RBCs was determined for each individual F2 mouse as depicted. Donor RBCs were stored for 7 days, spiked with a fresh HOD RBC tracer population, and then transfused into GFP mice with a B6xFVB F1 genetic background. Representative flow cytometry plots are shown. (C) QTL analysis using 24-hour recovery as a quantitative phenotype identified a single region of high significance over a broad range of chromosome 1, termed Rbcstor1. (D) QTL analysis using spontaneous hemolysis in the storage tube as a quantitative phenotype identified a single region of high significance over a broad range of chromosome 1, termed Rbcstor2. (E) QTL using 24-hour recovery as a phenotype on the subset of F2 mice containing the same allelotypes at Rbcstor1 did not identify any other contributing QTL. Likewise, taking a similar approach with spontaneous hemolysis and Rbcstor2, no additional contributing QTL was identified (data not shown). FDR, false discovery rate.