TY - JOUR
T1 - Functional analysis of gap junctions in ovarian granulosa cells
T2 - Distinct role for connexin43 in early stages of folliculogenesis
AU - Gittens, Joanne E.I.
AU - Mhawi, Abdul Amir
AU - Lidington, Darcy
AU - Ouellette, Yves
AU - Kidder, Gerald M.
PY - 2003/4/1
Y1 - 2003/4/1
N2 - Ovarian granulosa cells are coupled via gap junctions containing connexin43 (Cx43 or α-1 connexin). In the absence of Cx43, granulosa cells stop growing in an early preantral stage. However, the fact that granulosa cells of mature follicles express multiple connexins complicated interpretation of this finding. The present experiments were designed to clarify the role of Cx43 vs. these other connexins in the earliest stages of folliculogenesis. Dye injection experiments revealed that granulosa cells from Cx43 knockout follicles are not coupled, and this was confirmed by ionic current injections. Furthermore, electron microscopy revealed that gap junctions are extremely rare in mutant granulosa cells. In contrast, mutant granulosa cells were able to form gap junctions with wild-type granulosa cells in a dye preloading assay. It was concluded that mutant granulosa cells contain a population of connexons, composed of an unidentified connexin, that do not normally contribute to gap junctions. Therefore, although Cx43 is not the only gap junction protein present in granulosa cells of early preantral follicles, it is the only one that makes a significant contribution to intercellular coupling.
AB - Ovarian granulosa cells are coupled via gap junctions containing connexin43 (Cx43 or α-1 connexin). In the absence of Cx43, granulosa cells stop growing in an early preantral stage. However, the fact that granulosa cells of mature follicles express multiple connexins complicated interpretation of this finding. The present experiments were designed to clarify the role of Cx43 vs. these other connexins in the earliest stages of folliculogenesis. Dye injection experiments revealed that granulosa cells from Cx43 knockout follicles are not coupled, and this was confirmed by ionic current injections. Furthermore, electron microscopy revealed that gap junctions are extremely rare in mutant granulosa cells. In contrast, mutant granulosa cells were able to form gap junctions with wild-type granulosa cells in a dye preloading assay. It was concluded that mutant granulosa cells contain a population of connexons, composed of an unidentified connexin, that do not normally contribute to gap junctions. Therefore, although Cx43 is not the only gap junction protein present in granulosa cells of early preantral follicles, it is the only one that makes a significant contribution to intercellular coupling.
KW - Hemichannels
KW - Intercellular communication
KW - α-1 connexin
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U2 - 10.1152/ajpcell.00277.2002
DO - 10.1152/ajpcell.00277.2002
M3 - Article
C2 - 12620892
AN - SCOPUS:0037376189
SN - 0363-6143
VL - 284
SP - C880-C887
JO - American Journal of Physiology - Cell Physiology
JF - American Journal of Physiology - Cell Physiology
IS - 4 53-4
ER -