Zebrafish reveal wider role for gene linked to human albinism

— Tiny, striped zebrafish are helping scientists trace how a gene linked to albinism influences eye development, work that may ultimately help explain some of the vision problems experienced by people with the condition and guide the search for new treatments.

In a study published in Developmental Biology, Washington State University researchers found that mutations in OCA2, a gene responsible for one of the most common forms of albinism, caused unexpected changes in pigment cells, eye formation and the activity of dozens of other genes in zebrafish embryos.

The findings suggest OCA2 may play a wider role in development beyond helping produce melanin, the pigment that gives color to the skin, hair and eyes.

If similar processes occur in humans, the research could eventually help explain complications associated with albinism, including impaired vision and involuntary eye movement.

“We’re interested in understanding processes that you wouldn’t necessarily expect to depend on melanin, but it turns out they do,” said corresponding author Cynthia Cooper, a professor in WSU’s School of Molecular Biosciences at WSU Vancouver.

“It’s another surprising mechanism that cells are using to develop correctly.” Scientists have used zebrafish to investigate genetics and development for more than five decades, studying everything from heart development to neurological disorders and cancer.

Cooper has worked with the fish for more than 20 years.

Like people, zebrafish are vertebrates and use many of the same genes to produce pigment cells.

Their transparent embryos also develop quickly outside the body, allowing scientists to observe biological changes that would be difficult to study in humans.

For the new study, Cooper and her colleagues examined embryos carrying a mutation in the zebrafish version of the OCA2 gene.

They tracked how pigment cells and the eyes developed, then compared gene activity in embryos carrying the mutation with embryos that did not carry it.

The report adds to ongoing university-led research relevant to veterinary medicine, animal health, and clinical decision-making.

university website: Washington State University College of Veterinary Medicine