5 CD-1 wild-type embryos. Twenty-four hours after seeding, cells were transfected using Fugene6 (Roche) with various combinations of mCherry reporter vectors (SBE3-wtA or SBE3-mutA) and transcription factor vectors (Lhx6 and/or 3xFLAG-Lhx8). mCherry protein expression was detected 48 hr after transfection

by immunofluorescence. The number of mCherry+ cells was measured and represented in Figure 8C as the mean ± SEM from four independent experiments. EMSA was performed using the kit from Pierce. Briefly, each reaction (20 μl) consisted of ∼2 μg nuclear extract, 1 fmol/μl of biotinylated probes, with or without cold competitor probe (200, 50, or 10 fmol/μl) in binding buffer consisting of 10 mM Tris (pH 7.5), 50 mM KCl, 1 mM DTT, 5% glycerol, 1 mM EDTA, 50 ng/μl poly (dI-dC) (Sigma), and 50 ng/μl http://www.selleckchem.com/products/MS-275.html bovine serum albumin (New England Biolabs). LHX6, LHX8, and LDB1 proteins were generated by Fugene6 transfection MDV3100 clinical trial of HEK293 cells. After 48 hr, nuclear extracts were prepared using the Pierce nuclear extract kit. Biotinylated DNA probes were as follows: probe A corresponded to the 26–64 bp of the SBE3 Shh enhancer and included LHX site A ( Figure 8A); mutated probe A had the same nucleotide sequence as the wild-type probe A, but the LHX site core sequence (TAATCA) changed to TTTTTT. This work was supported

by the research grants to J.L.R.R. from Nina Ireland, Larry L. Hillblom Foundation, March of Dimes, Weston Havens Foundation,

NIMH R37 MH049428 and R01 MH081880; to J.J. from NIDCR K99 DE019486-01; and to H.W. and Y.Z. from the intramural research program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development/NIH. “
“Retinal ganglion cells (RGCs) relay visual information from the eye to the higher visual processing centers of the brain in all vertebrates. They do so by extending axons through the optic disc into the optic nerve and then projecting to their primary target, the superior colliculus in mammals. very En route, they pass through the diencephalon, forming a major commissure known as the optic chiasm. In vertebrates with frontally located eyes, subpopulations of RGC axons segregate at the optic chiasm to project to targets on both the ipsilateral and contralateral sides of the brain to establish binocular vision (reviewed by Erskine and Herrera, 2007 and Petros et al., 2008). In species with a small overlap in the visual field—for example, mice—the vast majority of RGCs projects contralaterally, with ipsilaterally projecting RGCs comprising only ∼3% of the total RGC population. Most ipsilateral RGCs originate in the ventrotemporal crescent of the mouse retina, where they are specified by the zinc-finger transcription factor ZIC2 (Herrera et al., 2003).