Developmental abnormalities of NT mouse embryos appear early after implantation

摘要: In mammals, cloning by nuclear transfer (NT) into an enucleated oocyte is a very inefficient process, even if it can generate healthy adults. We show that blastocysts derived from embryonic stem (ES) donor cells develop at high rate, correctly express the pluripotential marker gene Oct4 in ICM and display normal growth vitro. Moreover, majority of them implant uterus recipient females. combine embryological studies, expression analysis during gastrulation generation chimaeric embryos to identify developmental origin (stage tissue affected) NT embryo mortality. The died before mid-gestation defects arising early, either peri-implantation stages or period. first type defect non-cell autonomous epiblast rescued complementation with ES cells. second affects regulation shape but does not directly impair initial establishment patterning embryo. Only chimaeras formed aggregation tetraploid reveal no abnormalities gastrulation. These studies indicate trophoblast cell lineage primary source these defects. provide solid basis for understanding reprogramming errors embryos. addition, they unveil new aspects while increasing our knowledge on role crosstalk between extra-embryonic regions conceptus control morphogenesis.