Fig. 1
Targeted recombination of Acvr1tnR206H in FAPs causes HO. a Organization of the conditional Acvr1tnR206H knockin allele. b–e Validation of the fluorescence marking system using the MyoDiCre driver. In Acvr1tnR206H/+;R26NG/+;MyoDiCre/+ mice, developing skeletal muscle expressed the GFP lineage tracer (R26NG), but not tdTomato. All other tissues express tdTomato but not GFP. c–e Cryosection through a developing hindlimb muscle bed. The approximate section plane is shown in b. f,g Representative µCT images of the distal hindlimb 14 days following pinch injury of the gastrocnemius muscle in wild-type (f; n = 25 mice) and Acvr1tnR206H/+;R26NG/+;Tie2-Cre (g; n = 42 mice) mice. h Representative µCT image of the distal hindlimb of a SCID host 21 days following intramuscular transplantation of Acvr1R206H/+ FAPs (n = 7 mice). HO in g and h is pseudocolored green and heterotopic bone volume is given (mm3)
