Expression of nectin-2 in mouse granulosa cells.
OBJECTIVE
The development and maturation of the ovarian follicles are characterized by structural changes that require components involved in cell-cell adhesion systems. Recently a novel group of cell adhesion molecules named nectins has been identified. The present study examined expression and cell-specific localization of nectins during mouse follicular development.


METHODS
Expression of nectins in mouse ovary was investigated by immnuoblot analysis and immunohistochemistry. More precise localization was determined by electron microscopy.


RESULTS
Immunoblot analysis revealed expression of nectin-2 and nectin-3 but not nectin-1 in ovarian granulosa cells. Immunohistochemistry demonstrated expression of nectin-2 at cell-cell adhesion sites of granulosa cell layer in the primary and preantral follicles. Especially, intense immunoreactivity of nectin-2 accumulated around the zona pellucida. In antral follicles, the intensity of nectin-2 expression on granulosa cells was decreased. By electron microscopy nectin-2 was detected not only on thin extensions of granulosa cells penetrating the zona pellucida, but also on the attachment sites between thin extensions of granulosa cells and oocyte surface.


CONCLUSIONS
The restricted expression of nectin-2 in the granulosa cells of primary and preantral follicles might reflect some of the molecular changes in cell-cell adhesion during early follicular development.
Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Faculty of Medicine, Suita, Japan.
Rikako
R
Kawagishi
Masahiro
M
Tahara
Kenichiro
K
Morishige
Masahiro
M
Sakata
Keiichi
K
Tasaka
Wataru
W
Ikeda
Koji
K
Morimoto
Yoshimi
Y
Takai
Yuji
Y
Murata
D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002478:Cells, Cultured; D005260:Female; D006107:Granulosa Cells / Q000378:metabolism*; D015151:Immunoblotting; D007150:Immunohistochemistry; D051379:Mice; D008813:Mice, Inbred ICR; D008854:Microscopy, Electron; D023421:Models, Animal; D000075983:Nectins; D006080:Ovarian Follicle / Q000254:growth & development*; D010053:Ovary / Q000166:cytology* / Q000648:ultrastructure; D012680:Sensitivity and Specificity
D015815:Cell Adhesion Molecules; C000619015:Nectin1 protein, mouse; C000619017:Nectin3 protein, mouse; D000075983:Nectins