PUBLICATION

Zebrafish Lacking Circadian Gene per2 Exhibit Visual Function Deficiency.

Authors
Huang, D.F., Wang, M.Y., Yin, W., Ma, Y.Q., Wang, H., Xue, T., Ren, D.L., Hu, B.
ID
ZDB-PUB-180330-4
Date
2018
Source
Frontiers in behavioral neuroscience   12: 53 (Journal)
Registered Authors
Hu, Bing, Wang, Han
Keywords
contrast sensitivity, opsin, optokinetic response, per2, ribbon synapses, visual motor response
MeSH Terms
none
PubMed
29593513 Full text @ Front. Behav. Neurosci.
Abstract
The retina has an intrinsic circadian clock, but the importance of this clock for vision is unknown. Zebrafish offer many advantages for studying vertebrate vision and circadian rhythm. Here, we explored the role of zebrafish per2, a light-regulated gene, in visual behavior and the underlying mechanisms. We observed that per2 mutant zebrafish larvae showed decreased contrast sensitivity and visual acuity using optokinetic response (OKR) assays. Using a visual motor response (VMR) assay, we observed normal OFF responses but abnormal ON responses in mutant zebrafish larvae. Immunofluorescence showed that mutants had a normal morphology of cone photoreceptor cells and retinal organization. However, electron microscopy showed that per2 mutants displayed abnormal and decreased photoreceptor ribbon synapses with arciform density, which resulted in retinal ON pathway defect. We also examined the expression of three cone opsins by quantitative real-time PCR (qRT-PCR), and the expression of long-wave-sensitive opsin (opn1lw) and short-wave-sensitive opsin (opn1sw) was reduced in mutant zebrafish larvae. qRT-PCR analyses also showed a down-regulation of the clock genes cry1ba and bmal1b in the adult eye of per2 mutant zebrafish. This study identified a mechanism by which a clock gene affects visual function and defined important roles of per2 in retinal information processing.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping