One member of this family, Mf3, is expressed in a pattern suggesting a role for this gene in the development of the midbrain and forebrain as well as the presomitic mesoderm that forms the somites. The expression of Mf3 is shown below in Figure 1. We have recently generated another line of mice carrying a tau-lacZ reporter gene in the Mf3 locus. Figure 2 below shows an image of the tau-lacZ staining in the spinal nerves and the hypothalamus. Using the tau-lacZ fusion we can trace axonal processes in three dimensions and determine whether there are defects in the neuronal circuitry.
Upper right shows a higher magnification of the back of the head.
The lower left panel is a low magnification view of a sagital section of a similar embryo showing staining in the hypothalamus. At higher magnification, lower right, axonal processes are visible. Recent experiments have examined the expression of another winged helix gene, Hfh2. This gene has also been named Genesis because it is expressed at high levels in embryonic stem cells and is downregulated when the cells differentiate. A combination of ectopic misexpression experiments in transgenic mice overexpression in Xenopus embryos will test the hypothesis that this gene product is crucial for the generation of neural crest stem cells.