PUBLICATION

An alternative splice variant of zebrafish cx52.6 is expressed in retinal horizontal cells

Authors
Greb, H., Klaassen, L.J., Schultz, K., Kamermans, M., Zoidl, G., Weiler, R., Janssen-Bienhold, U.
ID
ZDB-PUB-180727-10
Date
2018
Source
Neuroscience   388: 191-202 (Journal)
Registered Authors
Kamermans, Maarten, Weiler, Reto, Zoidl, Georg
Keywords
Alternative C-terminus, Connexin53.4, Electrical coupling, Gap junctions
MeSH Terms
  • Alternative Splicing
  • Animals
  • Animals, Genetically Modified
  • Axons/metabolism
  • Cells, Cultured
  • Connexins/genetics
  • Connexins/metabolism*
  • Dendrites/metabolism
  • Gap Junctions/metabolism
  • Protein Isoforms/metabolism
  • RNA, Messenger/metabolism
  • Retinal Horizontal Cells/cytology
  • Retinal Horizontal Cells/metabolism*
  • Sequence Alignment
  • Zebrafish/anatomy & histology
  • Zebrafish/metabolism*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed
30048782 Full text @ Neuroscience
Abstract
Retinal horizontal cells (HCs) are inhibitory neurons, which modulate the transmission of light-elicited signals from photoreceptors to bipolar cells in the outer retina. HCs of the same physiological type are extensively coupled via gap junctions. In the zebrafish retina, the population of HCs comprises up to four morphologically distinct subtypes. Four different connexins (Cx52.6, Cx52.7, Cx52.9 and Cx55.5) were detected in these cells with overlapping expression patterns. In this study, we show that Cx52.6 is alternatively spliced in the retina, resulting in an additional isoform, designated as Cx53.4, which differs from the originally described Cx52.6 only by the final C-terminal peptide (12 vs. 4 aa). Further protein sequence alignments revealed that Cx53.4 represents the counterpart of alternatively spliced mouse Cx57 and human Cx62. RT-PCR analyses of mRNA expression in different adult zebrafish tissues showed that Cx53.4 is expressed exclusively in the retina. The localization of Cx53.4 protein within the retina was analyzed using a specific antibody. Immunofluorescence analyses demonstrated that the expression of Cx53.4 is restricted to HCs of all four subtypes. Further, immunoelectron microscopy confirmed the presence of Cx53.4 in gap junctions between HC dendrites and between their axon terminals.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping