|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
PROTEIN AND VESICLE TRAFFICKING, CYTOSKELETON
Departments of 1Physiology and Pharmacology, and 2Obstetrics and Gynaecology, The University of Western Ontario, London; and 3Children's Health Research Institute, London, Ontario, Canada
Submitted 17 June 2005 ; accepted in final form 26 August 2005
Genetic ablation of connexin37 (Cx37) or connexin43 (Cx43), the two gap junction proteins expressed by mouse ovarian granulosa cells, has been shown to result in impaired follicle development. We used patch-clamp techniques to evaluate quantitatively the contribution of these connexins to gap junctional intercellular communication (GJIC) among granulosa cells. The coupling conductance derived from a voltage step-induced capacitive current transient was used as a measure of GJIC in cultured granulosa cells. Using this method, we determined that the conductance of wild-type (84.1 ± 28.6 nS; n = 6) and Cx37-deficient granulosa cells (83.7 ± 6.4 nS; n = 11) does not differ significantly (P = 0.35), suggesting a limited contribution, if any, of Cx37 to granulosa cell coupling. In contrast, the conductance between granulosa cells of Cx43-deficient mice (2.6 ± 0.8 nS; n = 5) was not significantly different from that of single, isolated wild-type granulosa cells (2.5 ± 0.7 nS, n = 5; P = 0.83), indicating that Cx43-deficient granulosa cells were not electrically coupled. A direct measurement of transjunctional conductance between isolated granulosa cell pairs using a dual patch-clamp technique confirmed this conclusion. Interestingly, a partial rescue of folliculogenesis was observed when the Cx43-null mutation in C57BL/6 mice was crossed into the CD1 strain, and capacitive current measurement demonstrated that this rescue was not due to reestablishment of GJIC. These results demonstrate that folliculogenesis is impaired in the absence of GJIC between granulosa cells, but they also indicate that the severity is dependent on genetic background, a phenomenon that cannot be attributed to the expression of additional connexins.
ovarian follicle; oogenesis; connexin37; intercellular communication
This article has been cited by other articles:
![]() |
R. P. Norris, M. Freudzon, L. M. Mehlmann, A. E. Cowan, A. M. Simon, D. L. Paul, P. D. Lampe, and L. A. Jaffe Luteinizing hormone causes MAP kinase-dependent phosphorylation and closure of connexin 43 gap junctions in mouse ovarian follicles: one of two paths to meiotic resumption Development, October 1, 2008; 135(19): 3229 - 3238. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. A. M. Kusters, W. P. M. van Meerwijk, D. L. Ypey, A. P. R. Theuvenet, and C. C. A. M. Gielen Fast calcium wave propagation mediated by electrically conducted excitation and boosted by CICR Am J Physiol Cell Physiol, April 1, 2008; 294(4): C917 - C930. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Y. Li, D. Colley, K. J. Barr, S.-P. Yee, and G. M. Kidder Rescue of oogenesis in Cx37-null mutant mice by oocyte-specific replacement with Cx43 J. Cell Sci., December 1, 2007; 120(23): 4117 - 4125. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |