Transforming Growth Factor α (TGFα) Modulates the Effects of Genomic Imprinting and Prolongs Development of Parthenogenetic Mouse Embryos

Abstract

The effect of transforming growth factor α (TGFα) on the development of diploid parthenogenetic mouse embryos (CBA × C57BL/6)F1was studied. The embryos were in vitro treated with the TGFα at the morula stage. Upon reaching the blastocyst stage, each embryo was implanted into uterus of a pseudopregnant female. At a dose of 5 ng/ml, the TGFα was found to improve development of parthenogenetic embryos before implantation, increase significantly the number of developing blastocysts, and promote embryo implantation into uterus. After treatment with TGFα at a dose of 10 ng/ml, 4% of parthenogenetic embryos reached the stage of 30–45 somites and had forelimb and hindlimb buds; the crown rump length of the embryo size from vertex to sacrum was 2.0 to 3.8 mm. A well-developed placenta was observed in 6% of TGFα-treated parthenogenetic embryos that reached the somite stages. In the parthenogenetic embryos with the most prominent development (40–45 somites) treated with 10 ng/ml of TGFα, the placental diameter was 4.0 to 4.2 mm on day 12 of gestation, which is close to the placental size of the normal (fertilized) 11-day-old mouse embryos. Our results suggest that exogenous TGFα can modulate the effects of genomic imprinting significantly improving formation of trophoblast derivatives and promoting longer postimplantation development of parthenogenetic embryos.