PAX3 and Hyperglycemia: We previously reported that C57Bl/6J (B6) embryos, unlike FVB/NJ (FVB) embryos, are resistant to NTDs induced during diabetic pregnancy, despite similar levels of maternal hyperglycemia; this is correlated with failure to inhibit expression of Pax3, which is required for neural tube closure, in B6 embryos of diabetic mothers [19].