2010 OSU Molecular Life Sciences
Interdisciplinary Graduate Programs Symposium
Somites are the embryonic precursors of the vertebrae, ribs, and skeletal muscles. They form from the presomitic mesoderm (PSM) by a periodic segmentation process called somitogenesis. This process is controlled in part by a segmentation clock that requires the oscillatory expression of genes such as Lunatic fringe (Lfng). Expression levels of clock-linked genes oscillate with a two-hour period during mouse somitogenesis. For such rapid oscillations to play a functional role during development, clock function requires that the tight transcriptional control of Lfng expression be coupled with mechanisms that confer short half lives to the RNA and protein activity, and that regulate the rate of LFNG protein translation. We have examined post-transcriptional mechanisms that may regulate Lfng activity within the segmentation clock. We find that microRNAs may play a key role in the segmentation clock through their regulation of the Lfng transcript. Further, we propose a novel turnover mechanism for the LFNG protein, requiring protein processing and release from the cell.