Fig. 1.

Col1(2.3)⁺/PTX⁺ mice have bone-specific expression of PTX that is suppressed by administration of doxycycline. PTX expression was assessed in (A) a range of tissues isolated from 12-week-old Col1(2.3)⁺/PTX⁺ mice and littermate controls continuously maintained in the absence of doxycycline, (B) femurs derived from 12-week-old Col1(2.3)⁺/PTX⁺ mice bred and maintained either in the absence (–DOXY, n = 6) or presence (+DOXY, n = 8) of doxycycline, (C) femurs derived from male (n = 4) and female (n = 2) 12-week-old Col1(2.3)⁺/PTX⁺ mice maintained in the absence doxycycline, and (D) femurs derived from male (n = 6) and female (n = 6) 8-week-old Col1(2.3)⁺/PTX⁺ mice maintained in the absence doxycycline. All data were obtained by RT-qPCR analysis and are expressed as mean ± 1 SD. ^ap < .05; ^cp < .001.