title: Tetraploid Embryonic Stem Cells Maintain Pluripotency and Differentiation Potency into Three Germ Layers.
abstract: Polyploid amphibians and fishes occur naturally in nature, while polyploid mammals do not. For example, tetraploid mouse embryos normally develop into blastocysts, but exhibit abnormalities and die soon after implantation. Thus, polyploidization is thought to be harmful during early mammalian development. However, the mechanisms through which polyploidization disrupts development are still poorly understood. In this study, we aimed to elucidate how genome duplication affects early mammalian development. To this end, we established tetraploid embryonic stem cells (TESCs) produced from the inner cell masses of tetraploid blastocysts using electrofusion of two-cell embryos in mice and studied the developmental potential of TESCs. We demonstrated that TESCs possessed essential pluripotency and differentiation potency to form teratomas, which differentiated into the three germ layers, including diploid embryonic stem cells. TESCs also contributed to the inner cell masses in aggregated chimeric blastocysts, despite the observation that tetraploid embryos fail in normal development soon after implantation in mice. In TESCs, stability after several passages, colony morphology, and alkaline phosphatase activity were similar to those of diploid ESCs. TESCs also exhibited sufficient expression and localization of pluripotent markers and retained the normal epigenetic status of relevant reprogramming factors. TESCs proliferated at a slower rate than ESCs, indicating that the difference in genomic dosage was responsible for the different growth rates. Thus, our findings suggested that mouse ESCs maintained intrinsic pluripotency and differentiation potential despite tetraploidization, providing insights into our understanding of developmental elimination in polyploid mammals.
authors.affiliation: Laboratory of Veterinary Anatomy, Joint-Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan; Laboratory of Developmental Biology, Joint-Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Imai
authors.affiliation: Laboratory of Veterinary Anatomy, Joint-Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan; Laboratory of Developmental Biology, Joint-Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan; Biomedical Science Center for Translational Research (BSCTR), The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kano
authors.affiliation: Laboratory of Applied Genetics, Graduate School of Agricultural and Life Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Fujii
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, Miyazaki University, Miyazaki, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Takasawa
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, Miyazaki University, Miyazaki, Japan.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Wakitani
authors.affiliation: Laboratory of Veterinary Anatomy, Joint-Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Hiyama
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, Miyazaki University, Miyazaki, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Nishino
authors.affiliation: Laboratory of Veterinary Anatomy, Joint-Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan.
authors.forename: Ken Takeshi
authors.initials: KT
authors.lastname: Kusakabe
authors.affiliation: Laboratory of Veterinary Anatomy, Joint-Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kiso
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology; D002454:Cell Differentiation; D049109:Cell Proliferation; D019175:DNA Methylation; D004622:Embryo, Mammalian / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism / Q000637:transplantation; D005260:Female; D017930:Genes, Reporter; D005855:Germ Layers / Q000378:metabolism*; D051379:Mice; D057891:Tetraploidy; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D014157:Transcription Factors