PUBLICATION

Complexity of Gap Junctions between Horizontal Cells of The Carp Retina

Authors
Greb, H., Hermann, S., Dirks, P., Ommen, G., Kretschmer, V., Schultz, K., Zoidl, G., Weiler, R., Janssen-Bienhold, U.
ID
ZDB-PUB-161030-2
Date
2017
Source
Neuroscience   340: 8-22 (Journal)
Registered Authors
Weiler, Reto, Zoidl, Georg
Keywords
Connexin49.5, Connexin52.6, Connexin53.8, Connexin55.5, Electrical synapse, Hemichannel
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • Axons/metabolism
  • Blotting, Western
  • Carps/anatomy & histology*
  • Carps/metabolism*
  • Cell Line, Tumor
  • Connexins/metabolism
  • Dendrites/metabolism
  • Fish Proteins/metabolism
  • Gap Junctions/metabolism*
  • Immunohistochemistry
  • In Situ Hybridization
  • Mice
  • Microscopy, Immunoelectron
  • Polymerase Chain Reaction
  • Protein Isoforms
  • Retinal Horizontal Cells/cytology*
  • Retinal Horizontal Cells/metabolism*
  • Sequence Alignment
PubMed
27793781 Full text @ Neuroscience
Abstract
In the vertebrate retina, horizontal cells (HCs) reveal homologous coupling by gap junctions (gj), which are thought to consist of different connexins (Cx). However, recent studies in mouse, rabbit and zebrafish retina indicate that individual HCs express more than one connexin. To provide further insights into the composition of gj connecting HCs and to determine whether HCs express multiple connexins, we examined the molecular identity and distribution of gj between HCs of the carp retina. We have cloned four carp connexins designated Cx49.5, Cx55.5, Cx52.6 and Cx53.8 with a close relationship to connexins previously reported in HCs of mouse, rabbit and zebrafish, respectively. Using in situ hybridization, Cx49.5 expression was detected in different subpopulations of retinal neurons including HCs, whereas the Cx52.6 transcript was localized exclusively in HCs. Using specific antibodies, Cx55.5 and Cx53.8 were detected on dendrites of all four HC subtypes and axon terminals. Immunoelectron microscopy confirmed the presence of Cx55.5 and Cx53.8 in gap junctions between these processes and Cx55.5 was additionally observed in HC dendrites invaginating cone pedicles, suggestingits participation in the modulation of photoreceptor output in the carp retina. Furthermore, using single cell RT-PCR, all four connexins were detected in different subtypes of HCs, suggesting overlapping expression patterns. Thus, the composition of gj mediating homologous coupling between subtypes of carp HCs appears to be more complex than expected. Moreover, BLAST searches of the preliminary carp genome, using novel sequences as query, suggest that most of the analyzed connexin genes are duplicated in carp.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping