Differential reprogramming of somatic cell nuclei after transfer into mouse cleavage stage blastomeres.
Mammalian somatic cell cloning requires factors specific to the oocyte for reprogramming to succeed. This does not exclude that reprogramming continues during the zygote and cleavage stages. The capacity or role of zygotic and cleavage stages to reprogram somatic cell nuclei is difficult to assess due to the limited development of somatic cell nuclei transplanted into cytoplasts of these stages. Alternatively, tetraploid embryos have been used to study reprogramming and can be assessed for their contribution to extra-embryonic lineages. When mouse cumulus cell nuclei transgenic for Oct4-green fluorescent protein (GFP) were injected into intact two- and four-cell stage blastomeres, manipulated embryos developed into blastocysts with expression of Oct4-GFP as observed in embryos produced by nuclear transfer into metaphase II oocytes. However, only the latter contributed to extra-embryonic tissues in day 10.5 conceptuses, with the exclusion of the somatic genome in cells originating from transfer into blastomeres already at 5.5 days post conception. Somatic nuclei transferred into cleavage stage blastomeres reinitiated expression of an embyronic-specific transgene, but lacked the extent of reprogramming required for contribution to postimplantation development, even when complemented by an embryonic genome.
Eckardt
Sigrid
S
Center for Animal Transgenesis and Germ Cell Research, New Bolton Center, University of Pennsylvania, Kennett Square, Pennsylvania 19348, USA.
Leu
N Adrian
NA
Kurosaka
Satoshi
S
McLaughlin
K John
KJ
D000818:Animals; D002970:Cleavage Stage, Ovum; D019976:Cloning, Organism; D004268:DNA-Binding Proteins / Q000235:genetics; D004627:Embryonic Induction; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics; D006822:Hybrid Cells; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008846:Micromanipulation; D053652:Nuclear Transfer Techniques; D050814:Octamer Transcription Factor-3; D011003:Ploidies; D014157:Transcription Factors / Q000235:genetics
D004268:DNA-Binding Proteins; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D014157:Transcription Factors; D049452:Green Fluorescent Proteins