Zonula occludens-1 (ZO-1) is involved in morula to blastocyst transformation in the mouse.
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.
Wang
Hehai
H
Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, 1125 MRB IV, 2215 B. Garland Avenue, Nashville, TN-37232-0656, USA.
Ding
Tianbing
T
Brown
Naoko
N
Yamamoto
Yasutoshi
Y
Prince
Lawrence S
LS
Reese
Jeff
J
Paria
B C
BC
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
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