title: Zonula occludens-1 (ZO-1) is involved in morula to blastocyst transformation in the mouse.
abstract: It is unknown whether or not tight junction formation plays any role in morula to blastocyst transformation that is associated with development of polarized trophoblast cells and fluid accumulation. Tight junctions are a hallmark of polarized epithelial cells and zonula occludens-1 (ZO-1) is a known key regulator of tight junction formation. Here we show that ZO-1 protein is first expressed during compaction of 8-cell embryos. This stage-specific appearance of ZO-1 suggests its participation in morula to blastocyst transition. Consistent with this idea, we demonstrate that ZO-1 siRNA delivery inside the blastomeres of zona-weakened embryos using electroporation not only knocks down ZO-1 gene and protein expressions, but also inhibits morula to blastocyst transformation in a concentration-dependent manner. In addition, ZO-1 inactivation reduced the expression of Cdx2 and Oct-4, but not ZO-2 and F-actin. These results provide the first evidence that ZO-1 is involved in blastocyst formation from the morula by regulating accumulation of fluid and differentiation of nonpolar blastomeres to polar trophoblast cells.
authors.affiliation: Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, 1125 MRB IV, 2215 B. Garland Avenue, Nashville, TN-37232-0656, USA.
authors.forename: Hehai
authors.initials: H
authors.lastname: Wang
authors.forename: Tianbing
authors.initials: T
authors.lastname: Ding
authors.forename: Naoko
authors.initials: N
authors.lastname: Brown
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Lawrence S
authors.initials: LS
authors.lastname: Prince
authors.forename: Jeff
authors.initials: J
authors.lastname: Reese
authors.forename: B C
authors.initials: BC
authors.lastname: Paria
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D000071616:CDX2 Transcription Factor; D015820:Cadherins / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D018274:Electroporation; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009028:Morula / Q000166:cytology / Q000378:metabolism*; D050814:Octamer Transcription Factor-3 / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D011247:Pregnancy; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D062826:Zonula Occludens-1 Protein; D062827:Zonula Occludens-2 Protein
chemical_list: D000199:Actins; D000071616:CDX2 Transcription Factor; D015820:Cadherins; C487514:Cdx2 protein, mouse; D018398:Homeodomain Proteins; D008565:Membrane Proteins; D050814:Octamer Transcription Factor-3; D010750:Phosphoproteins; D034741:RNA, Small Interfering; C569043:Tjp1 protein, mouse; C569047:Tjp2 protein, mouse; D014157:Transcription Factors; D062826:Zonula Occludens-1 Protein; D062827:Zonula Occludens-2 Protein