Related Experiment Video
Updated: Oct 24, 2025
09:39
A Behavioral Assay to Measure Responsiveness of Zebrafish to Changes in Light Intensities
Published on: October 3, 2008
16.7K
Zfhx3 modulates retinal sensitivity and circadian responses to light
Steven Hughes1, Jessica K Edwards2, Ashleigh G Wilcox2
1Nuffield Department of Clinical Neurosciences, Sir William Dunn School of Pathology, Sleep and Circadian Neuroscience Institute, University of Oxford, Oxford, UK.
Summary
The short circuit mutation in the ZFHX3 gene impairs mouse vision, particularly affecting the pupillary light reflex and intrinsically photosensitive retinal ganglion cells (ipRGCs). This research highlights ZFHX3's role in retinal function and light response.
Area of Science:
- Neuroscience
- Genetics
- Ophthalmology
Background:
- Transcription factors regulate complex biological processes.
- Mutations in transcription factors can lead to pleiotropic effects.
- The zinc finger homeobox 3 (ZFHX3) transcription factor, specifically the short circuit (Sci) mutation (Zfhx3Sci/+), is linked to circadian rhythm disruptions.
Purpose of the Study:
- To investigate the impact of the Zfhx3Sci/+ mutation on retinal function.
- To analyze molecular, cellular, behavioral, and electrophysiological changes in the retina due to the mutation.
Main Methods:
- Immunohistochemistry to confirm ZFHX3 expression in retinal cells.
- Behavioral tests for light responsiveness and circadian entrainment.
- Electrophysiological recordings, including multi-electrode array recordings of retinal ganglion cells.
- Standard eye function tests like electroretinogram and optomotor response.
Main Results:
- ZFHX3 is expressed in various retinal cells, including amacrine and retinal ganglion cells (ipRGCs).
- Zfhx3Sci/+ mutants showed reduced locomotor activity and circadian entrainment.
- Mutants exhibited a hypersensitive pupillary reflex and increased light sensitivity in ipRGCs.
- Electroretinogram and optomotor responses were largely normal.
Conclusions:
- The Zfhx3Sci/+ mutation significantly affects retinal function, particularly ipRGCs and the pupillary light reflex.
- ZFHX3 plays a crucial role in regulating light responses within the retina.
- Further research is warranted to understand the therapeutic implications of ZFHX3 in vision disorders.
Related Concept Videos
02:19Circadian Rhythms and Gene Regulation
4.2K
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent...
4.2K
01:22Photoreceptors and Visual Pathways
6.9K
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category,...
6.9K
01:11Channel Rhodopsins
2.8K
Most organisms use photoreceptors to sense and respond to light. Examples of photoreceptors include bacteriorhodopsins and bacteriophytochromes in some bacteria, phytochromes in plants, and rhodopsins in the photoreceptor cells of the vertebral retina. The light-sensitive property of these receptors is because of the bound chromophores, such as bilin in the phytochromes and retinal in the rhodopsins.
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
2.8K
02:45Biological Clocks and Seasonal Responses
39.8K
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
39.8K
02:00Photoreceptors and Plant Responses to Light
26.5K
Light plays a significant role in regulating the growth and development of plants. In addition to providing energy for photosynthesis, light provides other important cues to regulate a range of developmental and physiological responses in plants.
26.5K