Sviluppo dell'organo sottocommessurale e della fibra di Reissner in un Teleosteo viviparo
In a viviparous Teleost, Gambusia affinis, the Reissner fibre is a product of a diffuse secretory activity of cells lining the ventricles at a very early stage. Then the flexural and subcommissural organs, being differentiated, feed the fibre, but only the subcommisural organ remains in connection with the Reissner fibre. The secretory activity of the subcommissural cells starts early (embryos 3.5 mm). The secretory substance appears always fine granulated and only in the supranuclear region. In...