Immunolocalization of a proton V‐ATPase in ovarian follicles of the tobacco hornworm Manduca sexta

Abstract

A monoclonal antibody, directed against an H ' translocating V-ATPase of the midgut of Manduca sexta, has been used for immunolocalization studies in ovarian follicles and testes of Manduca sexta. In testes, no distinct staining above background levels was observed. In vitellogenic follicles, V-ATPase irnmunoreactivity first appears in the cytoplasm of the trophocytes and then in the oocyte, but by far the strongest reaction is present in the region of the oolemma during endocytosis. All types of follicle cells surrounding both the oocyte and the trophocyte compartments show a distinct positive reaction. In the cylindrical follicle cells surrounding the oocyte, the irnrnunoreactivity is clearly restricted to the basal part. Our results suggest an important role for VATPase in vitellogenin uptake in Manduca, similar to that suggested on electrophysiological grounds in Hyalophora cecropia. o 1995 Wiley-Liss, Inc.

RNAi reveals the key role of Nervana 1 in cockroach oogenesis and embryo development

“…Despite these previous findings, silencing of Nervana in B. germanica did not impair patency, thereby suggesting that BgNrv1 is not involved in this process and therefore another ion pump, such the H + V-ATPase that coordinates ion exchange in insect oocytes and allow vitellogenin uptake by the oocyte membrane (Harvey et al, 1998;Janssen et al, 1995;O' Donnell and Sharda, 1994), could be the responsible for this function.…”

Egg Formation in Lepidoptera

“…The latter include about 86 µg of the lipid transport protein lipophorin, whose associated carotenoids give the yolk a bright yellow color, 20 µg of a 30-kDa microvitellogenin and smaller amounts of other hemolymph derivatives, including traces of several hexameric storage proteins. Manduca sexta adds a blue biliprotein, insectacyanin ( Kang et al 1995 ). The translucent chorion of this species allows the mix of carotenoids and insectacyanin to give the egg a cryptic leaf-green color.…”

“…The accumulation of microvitellogenin by Hyalophora follicles ( Kulakosky and Telfer 1989 ) and of insectacyanin by Manduca sexta follicles ( Kang et al 1995 ) also are saturable. But since their respective uptakes are not inhibited by either vitellogenin or lipophorin, separate receptors are indicated.…”

Purification and Characterization of Acid Phosphatase from the Egg of the Lady Beetle, Harmonia axyridis (Coccinellidae: Coleoptera)

“…Another enzyme in the egg, AP, was known to remove phosphate molecule from vitellin (Izumi et al, 1994;Fialho et al, 2002). AP of insect eggs showed very similar characteristics of lysosomal enzyme proved by inhibition tests, the optimum pH and the acidification of the yolk spear (Janssen et al, 1995;Ribolla et al, 2001;Fialho et al, 2002). However, the exact roles of AP on the process of yolk protein digestion was not known clearly.…”