Expression of eleven bHLH transcription factors shown in Figure 2A.

Of eleven transcription factors, Bhlhe40, Hes1 and Id4 were two-fold or greater up-regulated during osteoblast differentiation. On the other hand, these genes were one-half fold or greater down-regulated during adipocyte differentiation. Arrows indicate up- (↑), down-regulated (↓), or up- and downregulated (↑↓) bHLH genes. No change in expression is symbolized by the almost equal sign (≈). Crosstalk functions between osteoblast and adipocyte differentiation have been reported for Bhlhe40 [8], Hes1 [13], [14] and Id4 (this study), only.