Histone Modifications of H3K4me3, H3K9me3 and Lineage Gene
Expressions in Chimeric Mouse Embryo
Chimeric animal exhibits less viability and more fetal and placental abnormalities than normal animal. This study was aimed to determine the impact of mouse embryonic stem cells (mESCs) injection into the mouse embryos on H3K9me3 and H3K4me3 and cell lineage gene expressions in chimeric blastocysts.
Materials and Methods
In our experiment, at the first step, incorporation of the GFP positive mESCs (GFP-mESCs)
129/Sv into the inner cell mass (ICM) of pre-compacted and compacted morula stage embryos was compared. At the
second and third steps, H3K4me3 and H3K9me3 status as well as the expression of
Subzonal injection of GFP-mESCs at the pre-compacted embryos produced more chimeric blastocysts than
compacted embryos (P<0.05). The number of trophectoderm (TE), ICM, ICM/TE and total cells in chimeric blastocysts
were less than the corresponding numbers in blastocysts derived from other groups (P<0.05). In ICM and TE of
chimeric blastocysts, the levels of H3K4me3 and H3K9me3 were respectively decreased and increased compared
to the blastocysts of the other groups (P<0.05). Expressions of
In the present study, embryo compaction significantly reduced the rate of incorporation of injected mESCs into the ICM. Moreover, in chimeric blastocysts, the levels of H3K9me3 and H3K4me3 were altered. In addition, the expressions of pluripotency and cell fate genes were decreased compared to blastocysts of the other groups.