Working Hypothesis

Experimental data from surgical manipulations of Chick embryos done in our laboratory (Nowicki et al), as well as extensive published data generated by transgenic manipulations of mouse embryos (reviewed in Burke and Nowicki 2003) have led to the following hypothesis concerning the significance of the Lateral Somitic Frontier (LSF) during embryonic patterning.

The Hypothesis

We hypothesize that the two domains separated by the LSF represent not only different lineage communities, but also correspond to regional differences in environmentally based information. This information, in the form of the combinatorial expression of multiple regulatory genes (secreted factors, receptors and transcription factors), determines cell behavior. Our hypothesis states that cells come under different regulatory "control" as they cross the frontier.

The Burke Lab is currently involved in more detailed mapping of specific regions in the avian embryo (shoulder girdle, abdominal muscles), as well as a wide range of comparative studies. We are mapping the frontier in the mouse, and conducting comparative studies of body wall formation in embryos of lamprey, skate, turtle and snake. We are also involved in a variety of experimental work in chick and mouse to specifically test our hypothesis concerning the existence of independent patterning information on either side of the frontier.