Cytoskeletal organization of bee ovarian follicles during oogenesis

Abstract

The germ cells in the germarium of the bee meroistic polytrophic ovarian cysts remain interconnected by cytoplasmic bridges as a result of incomplete cell division. These intercellular bridges form a distribution pathway for the substances that initially determine which of the cystocytes will become oocyte and later conduct the products synthesized by the nurse cells to the oocyte. In the present work, the presence and distribution of cytoskeleton components, actin and tubulin were studied in ovaries of queens of Apis mellifera and Scaptotrigona postica, two eusocial species, using antibody against α- and β-tubulin and FITC-phalloidin, aiming to shed light on the role of these cytoskeleton elements in oogenesis. The immunofluorescent preparations were analyzed by laser scanning confocal microscopy. F-actin was detected in the intercellular bridges of both species. The tubulin distribution in cell cytoplasm of A. mellifera and S. postica also displayed similar pattern. The role of these elements in the oogenetic events responsible for both cell support and motility is discussed.