Scientists have developed a way to customize the zebrafish genome, according to a report from the Mayo Clinic. Up until now, scientists have been unable to fully use zebrafish genomes as a method of studying and learning more about human disease. The Mayo Clinic used a transcription activator-like effector nucleases (TALENs) to customize the zebrafish genome.

“By using genetic engineering tools called TALENs and synthetic DNA to make defined changes in the genomes of our fish, we are able to make small changes (just a few nucleotides) as well as add a specific sequence for biological gene switch applications,” said senior author Stephen Ekker, chief of the Mayo Clinic’s zebrafish team, in a statement. “This is the first time we’ve been able to make custom changes to the zebrafish genome.”

The zebrafish have a number of unique characteristics that make them a favorite of scientists for genetic studies. In fact, the transparency of zebrafish embryos is one of the leading reasons why they are so widely used for genetic studies. Scientists are able to see cells move around, organs form and a heart beat develop all within a zebrafish embryo.

With this new approach, scientists will be able to use zebrafish for a whole new set of experiments. Scientists hope to use zebrafish genomes to learn more about human disease. They plan to introduce small mutations within a zebrafish genome in order to see how it reacts. The ability to customize a zebrafish genome, researchers say, will eventually help scientists customize other animal model systems, including mice, rats and flies.

“To our knowledge, this TALEN toolkit also is the most active described to date,” said Mr. Ekker. “This has important implications for the growing TALEN field, whether used in fish or any other cells. We used this higher activity for genome editing applications. We also used it to conduct a series of somatic gene function assessments, opening the door to an array of non-germline experiments in zebrafish.”

The findings appeared recently in the journal Nature.