Journal of Cell Science, Vol 110, Issue 15 1751-1758, Copyright © 1997 by Company of Biologists

JOURNAL ARTICLES

Normal development of preimplantation mouse embryos deficient in gap junctional coupling

PA De Sousa, SC Juneja, S Caveney, FD Houghton, TC Davies, AG Reaume, J Rossant and GM Kidder
Department of Physiology, The University of Western Ontario, London, Canada.

The connexin multigene family (13 characterized members in rodents) encodes the subunits of gap junction channels. Gap junctional intercellular coupling, established during compaction of the preimplantation mouse embryo, is assumed to be necessary for development of the blastocyst. One member of the connexin family, connexin43, has been shown to contribute to the gap junctions that form during compaction, yet embryos homozygous for a connexin43 null mutation develop normally, at least until implantation. We show that this can be explained by contributions from one or more additional connexin genes that are normally expressed along with connexin43 in preimplantation development. Immunogold electron microscopy confirmed that roughly 30% of gap junctions in compacted morulae contain little or no connexin43 and therefore are likely to be composed of another connexin(s). Confocal immunofluorescence microscopy was then used to demonstrate that connexin45 is also assembled into membrane plaques, beginning at the time of compaction. Correspondingly, embryos homozygous for the connexin43 null mutation were found to retain the capacity for cell-to-cell transfer of fluorescent dye (dye coupling), but at a severely reduced level and with altered permeability characteristics. Whereas mutant morulae showed no evidence of dye coupling when tested with 6-carboxyfluorescein, dye coupling could be demonstrated using 2',7'-dichlorofluorescein, revealing permeability characteristics previously established for connexin45 channels. We conclude that preimplantation development in the mouse can proceed normally even though both the extent and nature of gap junctional coupling have been perturbed. Despite the distinctive properties of connexin43 channels, their role in preimplantation development can be fulfilled by one or more other types of gap junction channels.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				D. Tong, J. E. I. Gittens, G. M. Kidder, and D. Bai Patch-clamp study reveals that the importance of connexin43-mediated gap junctional communication for ovarian folliculogenesis is strain specific in the mouse Am J Physiol Cell Physiol, January 1, 2006; 290(1): C290 - C297. [Abstract] [Full Text] [PDF]

				D. H. Jones, T. Y. Li, E. Arystarkhova, K. J. Barr, R. K. Wetzel, J. Peng, K. Markham, K. J. Sweadner, G.-H. Fong, and G. M. Kidder Na,K-ATPase from Mice Lacking the {gamma} Subunit (FXYD2) Exhibits Altered Na+ Affinity and Decreased Thermal Stability J. Biol. Chem., May 13, 2005; 280(19): 19003 - 19011. [Abstract] [Full Text] [PDF]

				F. D Houghton Role of gap junctions during early embryo development Reproduction, February 1, 2005; 129(2): 129 - 135. [Abstract] [Full Text] [PDF]

				J. H.-C. Lin, J. Yang, S. Liu, T. Takano, X. Wang, Q. Gao, K. Willecke, and M. Nedergaard Connexin Mediates Gap Junction-Independent Resistance to Cellular Injury J. Neurosci., January 15, 2003; 23(2): 430 - 441. [Abstract] [Full Text] [PDF]

				Y. Landesman, F. R. Postma, D. A. Goodenough, and D. L. Paul Multiple connexins contribute to intercellular communication in the Xenopus embryo J. Cell Sci., January 1, 2003; 116(1): 29 - 38. [Abstract] [Full Text] [PDF]

				D. Rizos, A. Gutierrez-Adan, S. Perez-Garnelo, J. de la Fuente, M.P. Boland, and P. Lonergan Bovine Embryo Culture in the Presence or Absence of Serum: Implications for Blastocyst Development, Cryotolerance, and Messenger RNA Expression Biol Reprod, January 1, 2003; 68(1): 236 - 243. [Abstract] [Full Text] [PDF]

				F.D. Houghton, K.J. Barr, G. Walter, H.-D. Gabriel, R. Grummer, O. Traub, H.J. Leese, E. Winterhager, and G.M. Kidder Functional Significance of Gap Junctional Coupling in Preimplantation Development Biol Reprod, May 1, 2002; 66(5): 1403 - 1412. [Abstract] [Full Text]

				D. Rizos, P. Lonergan, M.P. Boland, R. Arroyo-Garcia, B. Pintado, J. d. l. Fuente, and A. Gutierrez-Adan Analysis of Differential Messenger RNA Expression Between Bovine Blastocysts Produced in Different Culture Systems: Implications for Blastocyst Quality Biol Reprod, March 1, 2002; 66(3): 589 - 595. [Abstract] [Full Text] [PDF]

				M Kumai, K Nishii, K Nakamura, N Takeda, M Suzuki, and Y Shibata Loss of connexin45 causes a cushion defect in early cardiogenesis Development, January 8, 2000; 127(16): 3501 - 3512. [Abstract] [PDF]

				S. C. Juneja, K. J. Barr, G. C. Enders, and G. M. Kidder Defects in the Germ Line and Gonads of Mice Lacking Connexin43 Biol Reprod, May 1, 1999; 60(5): 1263 - 1270. [Abstract] [Full Text]

				M Levin and M Mercola Gap junction-mediated transfer of left-right patterning signals in the early chick blastoderm is upstream of Shh asymmetry in the node Development, January 11, 1999; 126(21): 4703 - 4714. [Abstract] [PDF]