The properties of the Malpighian tubules of Drosophila melanogaster change along their length. The upstream main segments secrete K(+)-rich fluid at a high rate. From this, the lower tubules reabsorb significant amounts of water and K+. Under stimulation, K+ reabsorption is accelerated. In addition, the lower tubules acidify the fluid passed to them by the main segments and secrete Ca2+ into it, adding to that transported there by the upstream epithelium. In contrast to the lumen-positive transepithelial potential difference (TEP) of the main segments, the TEP in the lower tubules is much lower and becomes lumen-negative close to their downstream junction with the common ureter. We suggest that the role of the lower tubule is to reduce the flow of K(+)-rich fluid that passes to the hindgut; this allows the hindgut to process the flow of excretory fluid more thoroughly.
Fluid reabsorption and ion transport by the lower Malpighian tubules of adult female Drosophila.
M J O'Donnell, S H Maddrell; Fluid reabsorption and ion transport by the lower Malpighian tubules of adult female Drosophila.. J Exp Biol 1 January 1995; 198 (8): 1647–1653. doi: https://doi.org/10.1242/jeb.198.8.1647
Download citation file:
Advertisement
Cited by
In the field: an interview with Harald Wolf
(update)-Conversation.jpg?versionId=3772)
In our new Conversation, Harald Wolf talks about his fieldwork experiences working with desert ants in Tunisia to understand their navigation.
Propose a new Workshop
-GSWorkshop.png?versionId=3772)
Our Workshops bring together leading experts and early-career researchers from a range of scientific backgrounds. Applications are now open to propose Workshops for 2024, one of which will be held in a Global South country.
Julian Dow steps down and John Terblanche joins the JEB team
-NewEditor.png?versionId=3772)
After 15 years with the journal, Julian Dow from University of Glasgow, UK, is stepping down as a Monitoring Editor. We wish Julian all the best for the future and welcome John Terblanche, Stellenbosch University, South Africa, who is joining the team. Julian talks about his long association with The Company of Biologists and the journal and John tells us about his life and career in this News article.
An accelerometer-derived ballistocardiogram method for detecting heart rate in free-ranging marine mammals
-Whales.jpg?versionId=3772)
Max Czapanskiy and co show how the resting heart rates of blue whales are immortalized in the accelerometry traces collected by motion sensing data tags.
Global change and physiological challenges for Amazonian fish
-Review.png?versionId=3772)
In their Review, Adalberto Luis Val and Chris Wood discuss the physiological threats to the unique and diverse fish fauna of Amazonia.