Figure 4.

Confocal immunofluorescent labeling to localize GLUT8 protein expression in the blastocyst under basal and insulin-stimulated conditions. (A) Blastocyst under basal conditions stained with peptide-purified polyclonal antibody to the C terminus of GLUT8 (green) and propidium iodide (red) as a nuclear stain. This technique localizes the protein to the trophectoderm and primitive endoderm lining the blastocoel. (B) Higher magnification of the trophectoderm revealing GLUT8 in vesicle-like intracellular compartment. (C) Blastocyst under insulin-stimulated conditions stained with the same GLUT8 antibody. This technique demonstrates a general cellular redistribution of the protein with increased plasma membrane staining. (D) Higher magnification of the blastocyst cells revealing cytoplasmic and plasma membrane staining and less staining of the vesicle-like compartments.