RRC ID 12084
Author Jonz MG, Nurse CA.
Title Development of oxygen sensing in the gills of zebrafish.
Journal J. Exp. Biol.
Abstract Previous studies have described the morphology, innervation and O(2)-chemoreceptive properties of neuroepithelial cells (NECs) of the zebrafish gill filaments. The present work describes the ontogenesis of these cells, and the formation of functional O(2)-sensing pathways in developing zebrafish. Confocal immunofluorescence was performed on whole-mount gill preparations using antibodies against serotonin (5-HT) and a zebrafish-derived neuronal marker (zn-12) to identify the appearance and innervation of gill NECs during larval stages. NECs were first expressed in gill filament primordia of larvae at 5 days postfertilization (d.p.f.) and were fully innervated by 7 d.p.f. In vivo ventilation frequency analysis revealed that a behavioural response to hypoxia (11.2+/-2.8 min(-1)) developed in embryos as early as 2 d.p.f., and a significant increase (P<0.05) in the ventilatory response to hypoxia (200.8+/-23.0 min(-1)) coincided with innervation of NECs of the filaments. In addition, exogenous application of quinidine, a blocker of O(2)-sensitive background K(+) channels in NECs, induced hyperventilation in adults in a dose-dependent manner and revealed the development of a quinidine-sensitive ventilatory response in 7 d.p.f. larvae. This study shows that NEC innervation in the gill filaments may account for the development of a functional O(2)-sensing pathway and the hyperventilatory response to hypoxia in zebrafish larvae. At earlier stages, however, O(2)-sensing must occur through another pathway. The possibility that a new type of 5-HT-positive NEC of the gill arches may account for this earlier hypoxic response is discussed.
Volume 208(Pt 8)
Pages 1537-49
Published 2005-4
DOI 10.1242/jeb.01564
PII 208/8/1537
PMID 15802677
MeSH Analysis of Variance Animals Chemoreceptor Cells / embryology Chemoreceptor Cells / physiology* Dose-Response Relationship, Drug Gills / embryology* Gills / innervation Gills / physiology Microscopy, Fluorescence Neuroepithelial Cells / cytology Neuroepithelial Cells / physiology* Oxygen / physiology* Oxygen Consumption / drug effects Quinidine / pharmacology Zebrafish / embryology* Zebrafish / physiology
IF 3.017
Times Cited 69
Zebrafish ?