Du, Shao Jun (Jim)

Vertebrate skeletal muscles contain muscle fibers of several types, which can be broadly classified as slow or fast fibers, on the basis of differences in contraction speeds, metabolic activities, and motoneuron innervation. The major focus of my research is to try to understand how distinct types of muscle cells (slow vs fast) are induced and what are the signaling molecules involved in this process. Using zebrafish as a model, we have examined the potential roles of members of the hedgehog and TGF- gene families in the development of slow muscle fiber. Preliminary data suggest that Hedgehog signaling induces slow muscle cells, and that BMP-like signaling is involved in the specification of distinct slow muscle cell identity. Future research interests lie chiefly in understanding how the expression of Hedgehog genes are regulated and what are the signals required for the induction of fast muscle cells.