Gene-Editing Tool Helps Scientists Identify Endangered Salmon

    11 June 2021

    Scientists near San Francisco work to identify a type of endangered fish using a tool that was originally made for treating cancer.

    A special machine called Sherlock uses technology that started with CRISPR.

    CRISPR is a tool that is able to change the genetic material in specific cells. The technology is now used to change the structure of immune cells so they can recognize and fight cancer.

    The same technology is used in Sherlock. Sherlock, of course, is named after the famous investigator Sherlock Holmes.

    They do not, however, use Sherlock to change fish cells. Instead, the ocean researchers catch the fish, collect a small amount of mucus and then test the cells to find the genetic makeup of the fish.

    It can be done in about 30 minutes. In the past, the researchers would have to wait weeks or months to get test results.

    The technology is extremely helpful when looking at different species of Chinook salmon, because they look nearly the same. However, some of them are endangered, and the scientists need to keep track of them.

    Emily Funk waits for a Sherlock test on a sample from a Chinook salmon while on a research vessel on the San Joaquin River off Antioch, California, U.S., May 25, 2021. REUTERS/Nathan Frandin
    Emily Funk waits for a Sherlock test on a sample from a Chinook salmon while on a research vessel on the San Joaquin River off Antioch, California, U.S., May 25, 2021. REUTERS/Nathan Frandin

    Andrea Schreier is an associate professor at the University of California in Davis. She wrote a paper published in the journal Molecular Ecology Resources about a similar project with a different kind of fish known as smelt. Now she is working on the salmon.

    In the past, the scientists would catch the Chinook salmon and measure them to tell them apart.

    "It's not very accurate," she said.

    Schreier said when she and her team catch the fish, the Sherlock machine is able to quickly tell them if they have one of the special salmon. It's important because it allows the scientists to do things that will help the endangered salmon live longer. For example, they can catch them in lakes far away from the coast and take them by truck to the San Francisco Bay.

    In the past, the fish might have tried to make it to the Bay by swimming in rivers. However, due to climate change, the river water is sometimes too warm for the fish to make the trip safely.

    Schreier said she feels good about the project because she likes being able to assist with conservation.

    "I really want to work to, you know, maintain our ecosystems and our native populations as much as possible, given all of the pressures that we humans place on them through our different activities."

    Melinda Baerwald is an environmental program manager with the California Department of Water Resources. She also is working on the study.

    She said the work the team is doing on getting information about the fish is just one example of how new information about genetics will help people who do work like hers.

    "The power of genetics is now unlocked for other people to be able to use. And that's one of the big things that I think is changing how we're going to use this in our area for monitoring."

    I'm Dan Friedell.

    Nathan Frandino wrote this story for Reuters. Dan Friedell adapted it for Learning English. Susan Shand was the editor.

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    Words in This Story

    endangered - adj. used to describe a type of animal or plant that has become very rare and that could die out completely

    mucus –n. a thick liquid produced in some parts of the body

    specific –adj. special or particular

    accurate –adj. able to produce results that are correct

    monitor –v. to watch, observe, listen to, or check (something) for a special purpose over a period of time