Fig. 6. Fate mapping Nr4a1 expression with perinatal neuroinflammation.

a Experimental design for combining the Nr4a1-GFP-Cre and tdTomato loxP alleles in E15.5 embryos. Males heterozygous for Nr4a1-GFP-Cre were timed mated with females homozygous for tdTomato loxP to generate embryos that harbor both alleles at a 50% Mendelian frequency. For this comparison, tdTomato loxP mice were given intrauterine PBS and subcutaneous NS, LPS and NS or LPS and MgSO₄/BMTZ. Embryo brains were harvested 6 h following injections for fluorescence microscopy. b Representative micrographs for each genotype portraying GFP (green), indicative of real-time Nr4a1 expression, and tdTomato (red), expressed irreversibly following Cre recombination. BS1 (magenta) was used to label the vasculature. Merged images combine all three channels with DAPI (blue). c Positive (skeletal muscle, arrowhead) and negative controls (Cre negative littermates) confirm the specificity of the Cre-loxP combination represented in (a). Scale bars denote 100 µm.