(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 7. Helt represses Ngn genes. (A) Expression patterns of
proneural genes in the developing mouse mesencephalon. Expression of Ngns and
Helt is mutually exclusive in all the domains. By contrast, Mash1 is expressed
in essentially all domains and is coexpressed with Helt. (B) Ngn genes
are selectively expressed in glutamatergic progenitors. Ngn1 is coincidently
expressed in the VZ, where Brn3a+ neurons emerge. Ngn2 is
selectively expressed by glutamatergic progenitors as well as dopaminergic
progenitors. (C) Helt represses Ngn expression in the
mesencephalon. In transgenic embryos expressing Helt under the
control of the nestin enhancer, expression of Ngn1 and Ngn2 is repressed. By
contrast, Mash1 expression is unaffected. (D) Ngns are ectopically
expressed in presumptive GABAergic domains in the Helt-null mutant.
At E11.5, Ngn1 and Ngn2 are ectopically expressed in the m2 to m4 domains in
the Helt-/- mutant. At E12.5, the Ngn expression in the
dorsal m1 domain is upregulated and coexpression of GFP and the Ngns is
observed (inset).