Activity and coexpression of Drosophila black with ebony in fly optic lobes reveals putative cooperative tasks in vision that evade electroretinographic detection
Article first published online: 20 FEB 2013
Copyright © 2012 Wiley Periodicals, Inc.
Journal of Comparative Neurology
Volume 521, Issue 6, pages 1207–1224, 15 April 2013
How to Cite
Ziegler, A. B., Brüsselbach, F. and Hovemann, B. T. (2013), Activity and coexpression of Drosophila black with ebony in fly optic lobes reveals putative cooperative tasks in vision that evade electroretinographic detection. J. Comp. Neurol., 521: 1207–1224. doi: 10.1002/cne.23247
- Issue published online: 20 FEB 2013
- Article first published online: 20 FEB 2013
- Accepted manuscript online: 1 NOV 2012 08:53AM EST
- Manuscript Accepted: 23 OCT 2012
- Manuscript Revised: 18 AUG 2012
- Manuscript Received: 20 JUN 2012
- aspartate decarboxylase
Drosophila mutants black and ebony show pigmentation defects in the adult cuticle, which disclose their cooperative activity in β-alanyl-dopamine formation. In visual signal transduction, Ebony conjugates β-alanine to histamine, forming β-alanyl-histamine or carcinine. Mutation of ebony disrupts signal transduction and reveals an electroretinogram (ERG) phenotype. In contrast to the corresponding cuticle phenotype of black and ebony, there is no ERG phenotype observed when black expression is disrupted. This discrepancy calls into question the longstanding assumption of Black and Ebony interaction. The purpose of this study was to investigate the role of Black and Ebony in fly optic lobes. We excluded a presynaptic histamine uptake pathway and confirmed histamine recycling via carcinine formation in glia. β-Alanine supply for this pathway is independent of enzymatic synthesis by Black and β-alanine synthase Pyd3. Two versions of Black are expressed in vivo. Black is a specific aspartate decarboxylase with no activity on glutamate. RNA in situ hybridization and anti-Black antisera localized Black expression in the head. Immunolabeling revealed expression in lamina glia, in large medulla glia, in glia of the ocellar ganglion, and in astrocyte-like glia below the ocellar ganglion. In these glia types, Black expression is strictly accompanied by Ebony expression. Activity, localization, and strict coexpression with Ebony strongly indicate a specific mode of functional interaction that, however, evades ERG detection. J. Comp. Neurol., 521:1207–1224, 2013. © 2012 Wiley Periodicals, Inc.