We observed in Experiment 1 that gene expression profiles from alcohol treatment of embryos in this controlled culture system yielded two distinguishable patterns; comparison to the morphological data revealed that these were correlated with two different phenotypes: open (ALC-NTO) and closed neural tubes (ALC-NTC). The phenotypes and correlated gene expression differences were reproduced in Experiment 2. The embryos with open neural tubes (ALC-NTO) had more severe delays in brain and otic development than those with closed neural tubes (ALC-NTC) (Table 1). These different phenotypes are consistent with our previous in vivo observation in a liquid diet model of prenatal alcohol exposure in C57BL/6 mice, which resulted in partial penetration of incomplete neural tube closure (as late as embryonic day 15) and a cascade of deficits in midline structural development [43]. Finding this difference in development in experimentally controlled culture conditions indicates either a stochastic event or that an extremely sensitive gene-environment interaction is involved, e.g. different outcomes based on small differences in developmental stage at the time of exposure or small differences in tissue concentrations of alcohol across embryos. We
