Embryo

Culture of Zygotes Increases p53 Expression in B6 Mouse Embryos which Reduces Embryo Viability

Abstract
The expression of TRP53 in blastocysts that had been cultured from the zygote stage in vitro for 90 h was compared with blastocysts collected from the uterus in C57BL6 (B6) and F1 hybrid (B6CBF1) strain mice. In both strains there was little TRP53 detected in blastocysts collected from the uterus. There was some increased expression in cultured embryos from B6CBF1 mice and a marked increase in expression in cultured B6 blastocysts. In cultured B6 embryos there was an obvious accumulation of TRP53 within the nuclear region of embryonic cells. Cultured B6 zygotes had a significantly poorer rate of blastocyst formation, capacity to undergo implantation or form viable fetuses than cultured zygotes from B6CBF1 mice, or B6 blastocysts collected from the uterus. Trp53^-/- zygotes (B6 background) were significantly (p < 0.01) more likely to form blastocysts than sibling wildtype embryos, with Trp53^+/- embryos having an intermediate level of viability. Upon transfer of blastocysts to recipient females, Trp53^-/- blastocysts were more likely (p < 0.001) to form viable fetuses than either wildtype or heterozygous sibling blastocysts when the embryos resulted from culture of zygotes. This shift in viability did not occur when embryos were only subjected to 24 h culture from the compacted embryo stage. The results show that in the B6 strain, culture in vitro caused a marked increase in the expression and nuclear accumulation of TRP53. This expression was a significant cause of the loss of viability that occurs upon culture of zygotes from this strain in vitro.

Key words: Embryo • Assisted Reproductive Technology • Early development • Implantation • In vitro fertilization

This article has been cited by other articles:

				C. O'Neill Phosphatidylinositol 3-kinase signaling in mammalian preimplantation embryo development Reproduction, August 1, 2008; 136(2): 147 - 156. [Abstract] [Full Text] [PDF]

				C. O'Neill The potential roles for embryotrophic ligands in preimplantation embryo development Hum. Reprod. Update, May 1, 2008; 14(3): 275 - 288. [Abstract] [Full Text] [PDF]

				Y. Li, V. Chandrakanthan, M. L Day, and C. O'Neill Direct Evidence for the Action of Phosphatidylinositol (3,4,5)-Trisphosphate-Mediated Signal Transduction in the 2-Cell Mouse Embryo Biol Reprod, November 1, 2007; 77(5): 813 - 821. [Abstract] [Full Text] [PDF]

				B Mahsoudi, A Li, and C O'Neill Assessment of the Long-Term and Transgenerational Consequences of Perturbing Preimplantation Embryo Development in Mice Biol Reprod, November 1, 2007; 77(5): 889 - 896. [Abstract] [Full Text] [PDF]