Formation of spermatophore in ejaculatory duct of yellow mealworm beetle, Tenebrio molitor: SEM study
Main role of the accessory glands of Tenebrio molitor male is to facilitate transfer of sperm to the females. They produce heterogeneous secretions. Two anatomically distinct glands are present. While the tubular accessory glands (TAG) are composed of the secretory cells of one type only, the bean-shaped accessory glands (BAG) consist of eight cellular types. Low viscosity secretion of the TAG mix with sperms forming seminal fluid while high viscosity secretions (spermatophorins) of the BAG are largely transformed into the insoluble wall and core of the spermatophore. The prespermatophoric mass is transferred to the ejaculatory duct (EJD) where solidify and forms the complex spermatophore. Immunocytochemical experiments with monoclonal antibodies based on the colloidal gold technique were used in order to understand exact composition of individual layers of the spermatophore. In the recent study we have used SEM to observe the whole process of the formation of spermatophore in the ejaculatory duct.