Sensitized mutagenesis screen in Factor V Leiden mice identifies thrombosis suppressor loci

摘要: Factor V Leiden (F5L ) is a common genetic risk factor for venous thromboembolism in humans. We conducted sensitized N-ethyl-N-nitrosourea (ENU) mutagenesis screen dominant thrombosuppressor genes based on perinatal lethal thrombosis mice homozygous F5L (F5L/L and haploinsufficient tissue pathway inhibitor (Tfpi+/- ). F8 deficiency enhanced the survival of F5L/LTfpi+/- mice, demonstrating that lethality genetically suppressible. ENU-mutagenized F5L/L males F5L/+Tfpi+/- females were crossed to generate 6,729 progeny, with 98 offspring surviving until weaning. Sixteen lines, referred as "modifier 5 (MF5L1-16)," exhibited transmission putative subsequent generations. Linkage analysis MF5L6 identified chromosome 3 locus containing gene (F3). Although no ENU-induced F3 mutation was identified, haploinsufficiency (F3+/- suppressed lethality. Whole-exome sequencing MF5L12 an Actr2 point (p.R258G) sole candidate. Inheritance this variant associated suppression (P = 1.7 × 10-6), suggesting Actr2p.R258G thrombosuppressive. CRISPR/Cas9 experiments independent knockin/knockout demonstrated lethal, supporting hypomorphic or gain-of-function mechanism action Our findings identify Tfpi/F3 axis key regulators determining balance setting also suggest role process.