Figure 2. (A) Glut-1-deficient embryos; pregnant mice were anesthetized on day E12 for cesarean section. Four embryos were identified after uterine dissection: a, homozygous null GLUT-1−/−; b, wild-type GLUT-1+/+; c and d, heterozygous GLUT-1+/−. Embryos were photographed under saline solution. (B) A homozygous null GLUT-1−/− mouse and a wild-type GLUT-1+/+ mouse were compared. Scale calibrated in cm. Some morphological abnormalities, such as the lack of visibly detectable eyes and a comparatively diminutive rostral embryonic pole, in addition to their small size, were appreciated. Their GLUT-1+/+ and GLUT-1+/− littermates were normal morphologically.