抄録
[Objectives] The ng/fg parthenogenetic embryos harboring the 13-kb H19 deletion in ng allele successfully developed to term. However, the majority of the parthenotes exhibit severe growth retardation and die either just before or soon after recovery. The imprinted Igf2 and Dlk1 genes are thought to play important role for the extended development and survival. To explore a reason for the developmental retardation and the lethality in the parthenotes, we focused on hematopoiesis and assessed the expression of Igf2 and Dlk1, known as major regulator for hematopoietic stem cell differention and hematopoisis. [Methods] The ng/fg parthenotes were reconstructed by serial nuclear transfer. Total RNAs were extracted from the liver of E12.5 parthenotes ng(wt) /fg(wt) and ng (H19D13) /fg(wt) and controls. The cDNA was used for the quantitative gene expression analysis by real-time PCR. Liver cells of ng(wt) /fg(wt) and ng(H19D13) /fg(wt) parthenotes and controls at E12.5 were incubated with anti-Ter119 and anti-c-Kit, and followed by using FACS analysis. [Result] The expression of Igf2 in liver was repressed in ng(wt) /fg(wt) parthenotes, and decreased in ng(H19D13) /fg(wt) parthenotes at E15.5. The Dlk1 was repressed in the liver of both types of parthenotes. Further, the flow cytometry analysis of the liver cells at E12.5 showed that the immature erythroid cells were evidently increased in ng(wt) /fg(wt) parthenotes, but the more mature erythroid cells were decreased in ng(wt) /fg(wt) parthenogenetic liver. [Conclusion] The present results show that the retardation of liver development and hematopoietic stem cell differentiation in parthenotes could be involved in parthenogenetic lethality.
