Related Experiment Video
Updated: Jul 6, 2026

A Bioinformatics Pipeline for Investigating Molecular Evolution and Gene Expression using RNA-seq
Published on: May 28, 2021
The role of Pax genes in eye evolution
1Institute of Molecular Genetics, Videnska 1083, Prague 4, Czech Republic. kozmik@img.cas.cz
Abstract:
Anatomically widely different designs of animal eyes have long been thought to arise independently multiple times during evolution. This morphology-based view has been challenged by the identification of a highly conserved transcription factor Pax6 that plays a key role in eye development in both flies and mammals. The origin of Pax genes predates the origin of eyes and the nervous system since a PaxB-like gene, belonging to the Pax2/5/8 gene subfamily, was identified in sponge lacking nervous system. Structurally similar PaxB gene is implicated in visual system development in jellyfish, the most basal organism possessing complex eyes. The widespread use of Pax genes in the genetic program underlying eye formation throughout the animal kingdom raises a question why certain transcription factors have been frequently redeployed to build eyes. A model is proposed that provides a plausible explanation for the apparently ancient role of Pax genes in eye evolution.
Related Concept Videos
Gene Duplication and Divergence
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
Pleiotropy
The Retinoblastoma Gene
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 Gene
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,...
Genetic Lingo
Position-effect Variegation
