QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online July 2, 2004
Journal of Experimental Biology 207, 2835-2844 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.01089

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Bjornsson, C. S. Articles by Huebner, E. Search for Related Content PubMed PubMed Citation Articles by Bjornsson, C. S. Articles by Huebner, E.

Extracellular H⁺ dynamics during oogenesis in Rhodnius prolixus ovarioles

C. S. Bjornsson¹ and E. Huebner^2,*

¹ Laboratory of Nervous System Disorders, Wadsworth Center, Albany, NY 12201-0509, USA
² Department of Zoology, University of Manitoba, Winnipeg, MB, Canada R3T 2N2

^* Author for correspondence (e-mail: ehuebnr{at}cc.umanitoba.ca)

Accepted 18 May 2004

The spatiotemporal dynamics of transmembrane hydrogen ion (H⁺) fluxes during oogenesis were investigated in the telotrophic ovarioles of the insect, Rhodnius prolixus. Although Rhodnius ovarioles possess exaggerated morphological and electrical polarity between nurse cells and oocytes, little is known about H⁺ changes during oogenesis, despite the regulatory role played by H⁺ and pH in many relevant cellular processes. A number of dynamic extracellular H⁺ fluxes were measured along Rhodnius ovarioles, representing an oogenesis cycle, using a non-invasive, self-referencing, H⁺-selective probe. The interfollicular stalk separating adjacent follicles exhibited prominent H⁺ efflux that peaked during midvitellogenesis and declined during late vitellogenesis. H⁺ efflux in this region preceded stalk formation and, importantly, preceded the onset of vitellogenesis in the adjacent posterior follicle. H⁺ efflux was also observed over the terminal follicle, where specialized regions of the chorion were forming, and was still detected around follicle cells after ovulation, indicating that the somatic follicular epithelium produced this flux. Transmembrane H⁺ fluxes may drive intracellular pH changes or may stabilize pH_i in response to pH-altering events. H⁺ fluxes may play a role in processes that coincide spatially and temporally, including the onset of vitellogenesis, endocytosis, follicle cell cytoskeletal dynamics, and regulation of interfollicular feedback mechanisms.

Key words: hydrogen, H⁺, ion-selective probe, oogenesis, insect, Rhodnius prolixus