Expression of the insulin-responsive glucose transporter isoform 4 in blastocysts of C57/BL6 mice.
Glucose is the most important energy substrate for mammalian blastocysts. In preimplantation embryos glucose uptake is mainly mediated by facilitative glucose transporter molecules (GLUT). Employing RT-PCR in 3.5-day-old mouse blastocysts of strain C57/BL6 we have investigated the expression of the GLUT isoforms 1-4 and 8. We could not only detect GLUT 1, 3 and 8 but, in contrast to earlier studies, also the insulin-responsive isoform 4. GLUT2 was not expressed. The specificity for GLUT4 amplification was verified by sequence analysis. GLUT4 protein was localized by immunohistochemistry with two GLUT4 antibodies. It was found in ICM and trophoblast cells in the cytoplasmic compartment with a strong perinuclear staining. This is the first report on the expression of the insulin-sensitive GLUT4 isoform in mouse preimplantation embryos.
Tonack
S
S
Department of Anatomy and Cell Biology, Martin Luther University Faculty of Medicine, Grosse Steinstrasse 52, 06097 Halle, Germany.
Fischer
B
B
Navarrete Santos
A
A
D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D015870:Gene Expression; D051275:Glucose Transporter Type 4; D007124:Immunoenzyme Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000096:biosynthesis* / Q000235:genetics; D009124:Muscle Proteins / Q000096:biosynthesis* / Q000235:genetics; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D051275:Glucose Transporter Type 4; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; C495693:Slc2a4 protein, mouse