Related Experiment Video

Updated: Jun 6, 2026

Vibratome Sectioning Mouse Retina to Prepare Photoreceptor Cultures
11:22

Vibratome Sectioning Mouse Retina to Prepare Photoreceptor Cultures

Published on: December 22, 2014

Vax2 regulates retinoic acid distribution and cone opsin expression in the vertebrate eye

Giovanna Alfano1, Ivan Conte, Tiziana Caramico

  • 1Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy.

Development (Cambridge, England)
|December 15, 2010
PubMed

Insights

Vax2 gene inactivation disrupts eye development by altering retinoic acid metabolism and cone opsin expression. This research reveals Vax2

Area of Science:

  • Developmental Biology
  • Genetics
  • Neuroscience

Background:

  • Vax2 is an eye-specific homeobox gene crucial for establishing the dorsoventral eye axis.
  • Its precise molecular functions in eye development remain incompletely understood.

Purpose of the Study:

  • To investigate the role of Vax2 in regulating gene expression during eye development.
  • To elucidate the molecular pathways involving Vax2, particularly concerning retinoic acid (RA) metabolism and photoreceptor development.

Main Methods:

  • Transcriptome analysis of Vax2 knockout (Vax2(-/-)) mice at key developmental stages.
  • Quantitative analysis of retinoic acid (RA) metabolizing enzyme expression (Cyp26a1, Cyp26c1, Raldh3).
  • Assessment of cone photoreceptor gene (Opn1sw, Opn1mw) expression and rescue experiments with RA administration.
  • Functional studies in medaka fish (Oryzias latipes) using Vax2 gain- and loss-of-function assays.
  • Morphological and functional analysis of adult retinas in Vax2 mutant mice.

Main Results:

  • Vax2 inactivation altered the expression of RA-metabolizing enzymes, expanding the RA-free zone ventrally.
  • Downregulation of Raldh3 and upregulation of Cyp26a1/Cyp26c1 were observed in Vax2(-/-) mice.
  • Cone opsin gene expression was regionally altered in mutant retinas but rescued by RA administration.
  • Vax2 is necessary for proper intraretinal pathfinding of retinal ganglion cells.
  • Conservation of Vax2 function was confirmed in medaka fish.

Conclusions:

  • Vax2 plays a critical role in controlling intraretinal retinoic acid (RA) metabolism during eye development.
  • Proper RA homeostasis regulated by Vax2 is essential for correct cone opsin gene expression and retinal ganglion cell pathfinding.
  • These findings highlight Vax2 as a key regulator linking RA signaling to visual system development.

More Related Videos

Methodology for Studying Interactions of Vitamin A Membrane Receptors and Opsin Protein with their Ligands in Generating the Retinylidene Protein08:18

Methodology for Studying Interactions of Vitamin A Membrane Receptors and Opsin Protein with their Ligands in Generating the Retinylidene Protein

Published on: October 4, 2024

Cone-Enriched Cultures from the Retina of Chicken Embryos to Study Rod to Cone Cellular Interactions08:04

Cone-Enriched Cultures from the Retina of Chicken Embryos to Study Rod to Cone Cellular Interactions

Published on: March 20, 2021

Related Concept Videos

The Retinoblastoma Gene01:20

The Retinoblastoma Gene

Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
The Retinoblastoma Gene01:20

The Retinoblastoma Gene

Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
Photoreceptors and Visual Pathways01:22

Photoreceptors and Visual Pathways

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, whereas...
Anatomy of the Eyeball01:20

Anatomy of the Eyeball

The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle layer, the vascular tunic,...
The Retina01:32

The Retina

The retina is a layer of nervous tissue at the back of the eye that transduces light into neural signals. This process, called phototransduction, is carried out by rod and cone photoreceptor cells in the back of the retina.
Regulation of Angiogenesis and Blood Supply01:24

Regulation of Angiogenesis and Blood Supply

Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits.  Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...