Making Blind Zebrafish See

Scientists in the Conway Institute of Biomolecular & Biomedical Research have restored the sight of blind zebrafish whose eyes failed to develop due to a genetic mutation. The findings, published this week in Developmental Biology, are exciting first steps on a long road to understanding eye diseases in humans.

Dr. Breandan Kennedy and his colleagues at the University of Washington, Seattle and the Hubrecht Laboratory in Utrecht, Netherlands first identified a family of eyeless fish. They then discovered the gene that controls initial development of eye tissue (retinal homeobox 3 or rx3) and that mutations in this gene resulted in the eyeless fish.

When Dr. Kennedy and his research team introduced a normal copy of the rx3 gene into fish embryos that had inherited the mutated version of the gene, they discovered that this treatment restored normal eye development. Recent studies from researchers in the Unites States have shown that mutations in the human form of this gene cause anophthalmia, a disease in which eyes also fail to form.

Commenting on the findings, Dr. Kennedy said, “the sequencing of the human genome has given us the blueprint of life. However, we now need to determine the role of each of the ~30,000 genes in the genome, and their links to disease. Zebrafish provide an excellent system for this goal, as they are particularly suited to genetic studies and because many genes perform the same task in zebrafish and humans.”

This is the first publication from the largest Irish facility for the study of zebrafish, which was established last year after the opening of the Conway Institute in University College Dublin. These tiny, freshwater fish have many genetic traits that are similar to humans due to the fact that they also possess a backbone. This makes them ideal models for the study of inherited human diseases.