title: Chromosome remodeling and differentiation of tetraploid embryos during preimplantation development.
abstract: Although it is known that the tetraploid embryo contributes only to the placenta, the question of why tetraploid embryos differentiate into placenta remains unclear. To study the effect of electrofusion on the development of mouse tetraploid oocytes, mouse two-cell embryos were fused and cultured in vitro in Chatot-Ziomek-Bavister medium. After electrofusion, two chromosome sets from the tetraploid blastomere were individually duplicated before nuclear fusion. At 8-10 hr after electrofusion, each chromosome set was condensing and the nuclear membrane was breaking down. Around 12-14 hr after electrofusion, the two chromosome sets had combined together and had reached the second mitotic metaphase, at this point with 8n sets of chromosomes. Interestingly, we discovered that expression of OCT4, an inner cell mass cells biomarker, is lost by the tetraploid expanded blastocysts, but that CDX2, a trophectoderm cells biomarker, is strongly expressed at this stage. This observation provides evidence clarifying why tetraploid embryos contribute only to trophectoderm.
authors.affiliation: Department of Animal Biotechnology, KonKuk University, Seoul, Korea.
authors.forename: Mi-Ryung
authors.initials: MR
authors.lastname: Park
authors.forename: Ah-Reum
authors.initials: AR
authors.lastname: Lee
authors.forename: Hong-Thuy
authors.initials: HT
authors.lastname: Bui
authors.forename: Chankyu
authors.initials: C
authors.lastname: Park
authors.forename: Keun-Kyu
authors.initials: KK
authors.lastname: Park
authors.forename: Ssang-Goo
authors.initials: SG
authors.lastname: Cho
authors.forename: Hyuk
authors.initials: H
authors.lastname: Song
authors.forename: Jae-Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Van Thuan
authors.initials: VT
authors.lastname: Nguyen
authors.forename: Jin-Hoi
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D000071616:CDX2 Transcription Factor; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D002875:Chromosomes / Q000378:metabolism*; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology*; D005260:Female; D018398:Homeodomain Proteins / Q000378:metabolism; D007621:Karyotyping; D008297:Male; D051379:Mice; D050814:Octamer Transcription Factor-3 / Q000378:metabolism; D011247:Pregnancy; D057891:Tetraploidy; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D000071616:CDX2 Transcription Factor; C487514:Cdx2 protein, mouse; D018398:Homeodomain Proteins; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D014157:Transcription Factors