title: Genomic imprinting is variably lost during reprogramming of mouse iPS cells.
abstract: Derivation of induced pluripotent stem (iPS) cells is mainly an epigenetic reprogramming process. It is still quite controversial how genomic imprinting is reprogrammed in iPS cells. Thus, we derived multiple iPS clones from genetically identical mouse somatic cells. We found that parentally inherited imprint was variably lost among these iPS clones. Concurrent with the loss of DNA methylation imprint at the corresponding Snrpn and Peg3 imprinted regions, parental origin-specific expression of the Snrpn and Zim1 imprinted genes was also lost in these iPS clones. This loss of parental genomic imprinting in iPS cells was likely caused by the reprogramming process during iPS cell derivation because extended culture of iPS cells did not lead to significant increase in the loss of genomic imprinting. Intriguingly, one to several paternal chromosomes appeared to have acquired de novo methylation at the Snrpn and Zac1 imprinted regions in a high percentage of iPS clones. These results might have some implications for future therapeutic applications of iPS cells. Since DNA methylation imprint can be completely erased in some iPS clones at multiple imprinted regions, iPS cell reprogramming may also be employed to dissect the underlying mechanisms of erasure, reacquisition and maintenance of genomic imprinting in mammals.
authors.affiliation: Black Family Stem Cell Institute, Department of Developmental and Regenerative Biology, Department of Oncological Sciences, Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Takikawa
authors.affiliation: Black Family Stem Cell Institute, Department of Developmental and Regenerative Biology, Department of Oncological Sciences, Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Ray
authors.affiliation: Black Family Stem Cell Institute, Department of Developmental and Regenerative Biology, Department of Oncological Sciences, Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Black Family Stem Cell Institute, Department of Developmental and Regenerative Biology, Department of Oncological Sciences, Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Shamis
authors.affiliation: Black Family Stem Cell Institute, Department of Developmental and Regenerative Biology, Department of Oncological Sciences, Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Tien-Yuan
authors.initials: TY
authors.lastname: Wu
authors.affiliation: Black Family Stem Cell Institute, Department of Developmental and Regenerative Biology, Department of Oncological Sciences, Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Xiajun
authors.initials: X
authors.lastname: Li
mesh_terms: D000818:Animals; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D018392:Genomic Imprinting; D057026:Induced Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D008822:Mice, Transgenic