No abstract

The fat body (FB) consists of two types of cells: throphocytes and oenocytes. Throphocytes are related to intermediary metabolism storing lipids, carbohydrates, and proteins while oenocytes play role in the lipids and lipoproteins production. The vitellogenin is the precursor of egg yolk (vitelline) and is synthesized on FB. The aim of this work was to analyze the effects of hormones acting in bee reproduction, as juvenile hormone (JH) and ecdisteroids (20 HE) on FB cells, where vitellogenin is synthesized. For the study were chose nurse workers that in Melipona quadrifasciata anthidioides present activated ovaries and produce eggs, and virgin queens whose ovaries are not yet activated, presenting only previtellogenic follicles. FB trophocytes from these classes of bees were cultivated in media containing different amounts of JH and 20-HE. The effects on trophocytes cytoplasm reserves of lipids, proteins, and activity of acid phosphatase were compared by observing preparations from cultured FB, treated and control, by transmission electron microscopy (TEM). The results showed that the hormones effects are related to the bee's caste and functional ovary stage. The role of acid phosphatase on mobilization of the trophocyte reserves was also determined.

The fat body (FB) of insects is where yolk proteins are synthesized. Therefore, relationships between the FB and oogenesis were studied in nurse workers, virgins, and physogastric queens of Melipona quadrifasciata anthidioides, a stingless bee in which the workers produce and lay eggs while provisioning brood cells. The relationships between FB and oogenesis, as well as the routes of materials from hemolymph to the oocytes, were studied through the cytochemical detection of lipids by osmium imidazole (OI), carbohydrates by ruthenium red (RR) and basic proteins by ammoniacal silver (AS). The results show differences in the presence of the studied materials in FB trophocytes and ovary of the classes of females studied and oogenesis phases. Material that tested positive for the treatments was detected among the classes of individuals studied in both, trophocytes and oocytes, and in the route of those materials from hemolymph to the oocytes. The differences found among the individual classes indicate relationships with the nutrition and adaptation to the parsimonious use of nutrients in the metabolism of reproduction.