Histotypic in vitro reorganization of dissociated cells from mouse fetal gonads

Cell suspensions obtained from the testes of 13.5-14.5 day post coitum (dpc) mouse embryos reaggregate in cord-like structures following in vitro culture for 24 h on a reconstituted basement membrane (Matrigel). Ovarian cells of the same fetal age or cell suspensions from sex indifferent gonadal ridges (11.5 dpc embryos) form an organized cell network but not cord-like structures. Antibodies directed against laminin or against the alpha 6 subunit of its integrin receptor prevent such morphogenetic processes. The addition of 5 micrograms/ml cycloheximide, cytochalasin B or tunicamycin also inhibits the phenomenon. Interestingly, compounds that increase intracellular cyclic AMP (cAMP) (dbcAMP, forskolin and isobutyl-1-methylxanthine) induce embryonic testicular cells to organize into structures similar to those assembled by ovarian or sex indifferent cell suspensions. These findings offer a simple in vitro model for studying some aspects of early gonad development and provide novel experimental evidence that cell motility and cell-cell adhesion, possibly regulated by cAMP dependent mechanisms, are likely to play an important role in gonad morphogenesis.