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Updated: Apr 14, 2026
Loss- and Gain-of-function Approach to Investigate Early Cell Fate Determinants in Preimplantation Mouse Embryos
Published on: June 6, 2016
Dysfunction in gap junction intercellular communication induces aberrant behavior of the inner cell mass and frequent
Kazue Togashi1, Jin Kumagai, Emiko Sato
1Department of Obstetrics and Genecology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan.
Purpose:
We investigated the role of gap junctions (GJs) in embryological differentiation, and observed the morphological behavior of the inner cell mass (ICM) by time-lapse movie observation (TLM) with gap junction inhibitors (GJis).
Methods:
ICR mouse embryos were exposed to two types of GJis in CZB medium: oleamide (0 to 50 μM) and 1-heptanol (0 to 10 mM). We compared the rate of blastocyst formation at embryonic day 4.5 (E4.5) with E5.5. We also observed and evaluated the times from the second cleavage to each embryonic developing stage by TLM. We investigated embryonic distribution of DNA, Nanog protein, and Connexin 43 protein with immunofluorescent staining.
Results:
In the comparison of E4.5 with E5.5, inhibition of gap junction intercellular communication (GJIC) delayed embryonic blastocyst formation. The times from the second cleavage to blastocyst formation were significantly extended in the GJi-treated embryos (control vs with oleamide, 2224 ± 179 min vs 2354 ± 278 min, p = 0.013). Morphological differences were traced in control versus GJi-treated embryos until the hatching stage. Oleamide induced frequent severe collapses of expanded blastocysts (77.4 % versus 26.3 %, p = 0.0001) and aberrant ICM divisions connected to sticky strands (74.3 % versus 5.3 %, p = 0.0001). Immunofluorescent staining indicated Nanog-positive cells were distributed in each divided ICM.
Conclusions:
GJIC plays an important role in blastocyst formation, collapses of expanded blastocysts, and the ICM construction in mouse embryos.
