Changes in mouse femoral head transcriptome after FGFR3 constitutive activation

Achondroplasia (ACH), the most common form of human dwarfism is caused by a mutation in the Fibroblast Growth Factor Receptor 3 (FGFR3) gene, resulting in constitutive activation of the receptor. In order to gain insight into molecular mechanisms involved in the physiopathology, a conditional mouse model carrying the Y367C mutation corresponding to the human Y373C TDI mutation was produced (fgfr3neoY367C/+). Crossing these mice with CMV-CRE mice produces dwarf fgfr3Y367C/+ and fgfr3+/+ controls littermates. Dwarf fgfr3Y367C/+ mice exhibited skeletal dysplasia at birth, the phenotype becoming progressively more pronounced as the mice got older, with reduced length of long bone, narrow trunk, short ribs and macrocephaly. Histological examination of epiphyseal growth plates showed a disorganized growth plate, with reduced size of the hypertrophic and proliferative zone and an accelerated secondary ossification center formation (full phenotype description in Pannier S et al, Activating Fgfr3 Y367C mutation causes hearing loss and inner ear defect in a mouse model of chondrodysplasia. Biochimica et biophysica acta 2009; Pannier S et al, Delayed bone age due to a dual effect of FGFR3 mutation in Achondroplasia. Bone 2010; Jonquoy A et al, A novel tyrosine kinase inhibitor restores chondrocyte differentiation and promotes bone growth in a gain-of-function Fgfr3 mouse model. Human molecular genetics 2012; Martin L et al, Constitutively-active FGFR3 disrupts primary cilium length and IFT20 trafficking in various chondrocyte models of achondroplasia. Human molecular genetics 2018). Three pairs of Fgfr3Y367C/+ female and Fgfr3+/+ controls littermates were produced at 4 time points (d7, d14, d21 and d28).