Whole Exome Sequencing of CMT2D mice

Despite CMT2D mice with P234KY mutation in the Gars gene exhibiting severe motor defects in C57BL/6J background, this phenotype was significantly attenuated when this strain was outcrossed with CAST/EiJ mice. However, only minimal improvement was observed when outcrossing CMT2D mice with BALB/cJ mice. These observations suggest the potential presence of genetic modifiers in CAST/EiJ mice that influence CMT2D neuropathy. To identify possible genetic modifiers, CMT2D mice with C57BL/6J (BL6) and CAST/EiJ (CAST) hybrid genetic backgrounds (F1 CMT2DCAST/BL6) were backcrossed to wild-type C57BL/6J mice for at least 5 generations. This process aimed to dilute the single nucleotide polymorphisms (SNPs) originating from the CAST/EiJ genetic background. Subsequent whole-exome sequencing (WES) was conducted to identify CAST-specific SNPs in CMT2D offspring that maintain an alleviated CMT2D phenotype (F6 CMT2DCAST/BL6-mild). By further comparing these SNPs with those identified in CMT2D offspring experiencing a loss of the alleviation effect (F6 CMT2DCAST/BL6-severe).