To clarify the relationship between neural crest cells and various developmental eye abnormalities, pregnant mice were administered an intraperitoneal injection of 12.5 mg/kg retinoic acid (RA) suspended in corn oil on day 7 of pregnancy (RA group). Control mice received an equal volume of corn oil only (control group). The fetuses were removed by laparotomy on day 18 of gestation. The fetal mo...