CRYOPRESERVATION OF MOUSE EMBRYOS AFFECTS LATER EMBRYONIC-DEVELOPMENTPOSSIBLY THROUGH REDUCED EXPRESSION OF THE GLUCOSE-TRANSPORTER GLUT1

In order to study the effects of cryopreservation on later embryonic d evelopment, two-cell mouse embryos were frozen, thawed, and then allow ed to develop into blastocysts. The percentage of cryopreserved embryo s which developed into blastocysts was significantly lower than that o f fresh two-cell embryos. The amount of glucose incorporation in terms of H-3-2-deoxyglucose uptake in blastocysts developed in vivo, and in vitro from fresh or frozen-thawed two-cell embryos, was 473 +/- 108, 105 +/- 75, and 43.0 +/- 28.3 fmol per embryo per hour, respectively. Quantification of glucose transporter GLUT1 in these embryos by Wester n blotting was reflective of the degree of glucose incorporation. The implantation rate of blastocysts developed in vitro from frozen-thawed two-cell embryos (22.0%) was significantly lower than that developed in vivo (41.1%). These data suggest that cryopreservation may have lat er consequences on embryonic development through a mechanism that invo lves altered GLUT1 expression. (C) 1997 Wiley-Liss, Inc.