What Can a Zebrafish with No Blood Cells Tell Us about Blindness?

The cloche mutant zebrafish
The cloche mutant zebrafish can be recognized by its swollen heart and lack of blood cells. But it also develops a lens cataract that can be used to test strategies for preventing blindness.

3/12/19 ASHLAND, Ohio - An Ashland University biology professor and his team of undergraduate students have asked how a type of zebrafish, used for years to study the cardiovascular system, develops eye lens cataracts, a disease that continues to be the greatest source of human blindness worldwide. 

While previous work suggested that these zebrafish produced less of one crucial lens protein, triggering cloudiness in their lenses, Dr. Mason Posner and his students used two techniques that measure levels of gene expression to suggest that this might not be the case.

“Instead, it seems the abnormal lenses in these fish are caused by a more general stress resulting from the lack of another gene that controls the production of blood cells,” Posner said.

Posner’s lab collaborated with Dr. Andor Kiss, director for the Center for Bioinformatics and Functional Genomics at Miami University of Ohio, to compare the expression of over 23,000 genes between the zebrafish with cataracts and zebrafish with normal lenses.

“These research results will be published in the online open access journal PLOS ONE on March 12, 2019, and allow the zebrafish to be used to better understand the factors that cause lens cataract, and how it might be prevented,” Posner said.

“These experiments found that genes for the alpha-crystallins, lens proteins known to prevent the appearance of cataracts, were used at the same levels in both groups,” Posner said. “However, a number of stress genes that become active when tissues are experiencing physiological stress, were more active.”

Posner believes that future studies can help connect these stresses to the development of cataract.

Now that the nature of this zebrafish lens cataract has been described, Posner and his students plan to test the ability of various alpha-crystallins to prevent it from developing.

“These experiments will provide a novel way to test strategies for blocking the appearance of cloudiness leading to human blindness,” he said. “This work is funded by the National Eye Institute of the National Institutes of Health through their AREA program, which supports research training of undergraduate students in biomedical sciences.”

Ashland University, which has been ranked in the top tier of colleges and universities in U.S. News and World Report’s National Universities category, is a mid-sized, comprehensive private university conveniently located a short distance from Akron, Cleveland and Columbus, Ohio. Religiously affiliated with the Brethren Church, Ashland University (www.ashland.edu) deeply values the individual student and offers a unique educational experience that combines the challenge of strong, applied academic programs with a faculty and staff who build nurturing relationships with their students. ###