Figure 1. Tbx15 is highly and specifically expressed in glycolytic skeletal muscle.

(a) X-gal-stained hind limbs from 3-month-old Tbx15^LacZ/+ males. (b) qPCR analysis of Tbx15 expression from C2C12 cells during myogenic differentiation. Data are shown as mean±s.e.m. of triplicate samples and repeated three times (upper panel). Western blot of Tbx15 from protein extracts from the same cells using tubulin as a loading control (lower panel). (c) Expression level of Tbx15 mRNA was compared by northern blot of RNA isolated from tissues from of 8-week-old male and female (ovary) C57BL/6 mice. This experiment has been performed once. (d) qPCR analysis of Tbx15 expression from muscle groups of 8-week-old male C57BL/6 mice. Data are shown as mean±s.e.m. of six samples (upper panel). Western blot of Tbx15 from protein extracts made from the same muscles using tubulin as a loading control (lower panel). (e) Fluorescent in situ hybridization for Tbx15 in quadriceps muscle and immunofluorescence for Tbx15 in tibialis anterior muscle of 8-week-old random fed male mice. The photographs were taken at × 10 magnification. The photographs were taken at × 10 magnification. Scale bar, 100 μM. (f) X-gal-stained representative sections of soleus and EDL from 8-week-old Tbx15^LacZ males (n=3). Slides were lightly counterstained with eosin. Pictures were taken at × 20 magnification. Scale bar, 50 μM. (g) Immunofluorescence for Tbx15 and succinate dehydrogenase staining was performed on serial sections of tibialis anterior muscle of 8-week-old random fed male mice. Glycolytic fibres are marked with red crosses. The photographs were taken at × 10 magnification. Scale bar, 100 μM (h) Immunofluorescence for Tbx15 and succinate dehydrogenase staining was performed on serial sections. Five digital images (× 20) from non-overlapping fields were taken from each slide (total 20 fields per group), and oxidative and glycolytic muscle fibres were scored for Tbx15 expression. Values are mean±s.e.m. of four animals.