Fig 7. Hypomorphic Abcc6 mutation segregates with calcification phenotype in progeny of fetuin-A deficient DBA/2 x C57BL/6 hybrid mice.

a, One male D2, Ahsg-/- mouse was naturally mated with one female B6, Ahsg-/- mouse (parental generation–P). b, Three breeding pairs of their hybrid progeny (F₁) produced 177 F₂-offspring (86 male, 91 female), which were genotyped by PCR and genomic sequencing for the hypomorphic Abcc6 single nucleotide polymorphism rs32756904. Calcification was individually scored by computed tomography and segmentation of non-skeletal mineralized tissue (red color). Calcification was scored in five categories ranging from no calcified lesions detected (I), one calcified lesion detected in the brown adipose tissue BAT (II), more than one calcified lesion detected in BAT, but not in other tissues (III), numerous calcified lesions detected in BAT, kidney and myocard (IV), and numerous massive calcified lesions in BAT, kidney, myocard and axillary skin (V). The clear segregation of scores with SNP rs32756904 suggests that at the most 1–2 additional unlinked genes besides Fetua/Ahsg, Trpm6, and Abcc6 determine the severity of the calcification phenotype of the mice.