Role of occludin, a tight junction protein, in blastocoel formation, and in the paracellular permeability and differentiation of trophectoderm in preimplantation mouse embryos.
Tight junctions (TJ) are critical for blastocoel formation in mammalian embryos. The present study aimed to examine the role of tight junctions in the differentiation of the trophectoderm (TE), and in the pluripotency of blastomeres, as well as in the formation and integrity of the blastocoel. We examined the effect of occludin antibody on blastocoel formation, blastocyst permeability, and expression of H19 and Oct-4, markers of TE differentiation and blastomere pluripotency, respectively. Eight-cell mouse embryos and morulae were cultured in the presence or absence of occludin antibody for 31 h. Occludin antibody inhibited blastocoel formation and increased permeability of the TE of nascent and expanding blastocysts to FITC-dextran (4 kDa), a permeability tracer. At the same time Oct-4 expression increased while expression of H19 became barely detectable. These observations indicate that occludin is involved in establishing the blastocoel, as well as in maintaining its impermeability, and that the development of tight junction is critical for TE formation in mouse embryos.
Kim
Jinmee
J
Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791, Korea.
Gye
Myung Chan
MC
Kim
Moon Kyoo
MK
D000818:Animals; D000906:Antibodies / Q000378:metabolism; D015415:Biomarkers; D001755:Blastocyst / Q000166:cytology* / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D062793:Occludin; D050814:Octamer Transcription Factor-3; D009865:Oocytes / Q000502:physiology; D010539:Permeability; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism*; D013997:Time Factors; D014157:Transcription Factors
D000906:Antibodies; D015415:Biomarkers; D004268:DNA-Binding Proteins; C094335:H19 long non-coding RNA; D008565:Membrane Proteins; D062793:Occludin; C568986:Ocln protein, mouse; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D014157:Transcription Factors