Generation of Col1a1-Krm2 transgenic mice.

(A) Schematic presentation of the construct used for osteoblast-specific over-expression of Krm2 (top) and identification of three transgenic founder animals (arrows) by Southern Blotting (bottom), one of them dying at the age of 10 weeks. (B) Von Kossa/van Gieson staining of non-decalcified vertebral body sections from 10 weeks old female wildtype mice (n = 3), the dead founder animal (#2) and age-matched female transgenic offspring from the two other founders (n = 3, scale bars, 1 mm). The transgene copy numbers, as well as the trabecular bone volume (BV/TV, bone volume per tissue volume) is given below. (C) Transgene-specific RT-PCR expression analysis revealing expression in bone and weak expression in the eye. (D) Northern Blotting comparing Krm2 expression in transgenic mice compared to wildtype littermates.