[ti:Gene-Editing Tool Helps Scientists Identify Endangered Salmon] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.04]Scientists near San Francisco work [00:03.36]to identify a type of endangered fish [00:07.48]using a tool that was originally made for treating cancer. [00:13.64]A special machine called Sherlock [00:17.72]uses technology that started with CRISPR. [00:23.40]CRISPR is a tool that is able to change [00:27.52]the genetic material in specific cells. [00:32.20]The technology is now used to change the structure [00:37.92]of immune cells so they can recognize and fight cancer. [00:44.76]The same technology is used in Sherlock. [00:49.76]Sherlock, of course, [00:51.80]is named after the famous investigator Sherlock Holmes. [00:58.64]They do not, however, use Sherlock to change fish cells. [01:06.08]Instead, the ocean researchers catch the fish, [01:11.96]collect a small amount of mucus and then test the cells [01:18.68]to find the genetic makeup of the fish. [01:23.56]It can be done in about 30 minutes. [01:27.32]In the past, the researchers would have to wait weeks [01:32.04]or months to get test results. [01:36.60]The technology is extremely helpful [01:39.80]when looking at different species of Chinook salmon, [01:45.16]because they look nearly the same. [01:48.60]However, some of them are endangered, [01:53.04]and the scientists need to keep track of them. [01:57.36]Andrea Schreier is an associate professor [02:00.72]at the University of California in Davis. [02:04.32]She wrote a paper published in the journal Molecular Ecology Resources [02:11.20]about a similar project with a different kind of fish known as smelt. [02:18.00]Now she is working on the salmon. [02:21.76]In the past, the scientists would catch the Chinook salmon [02:27.24]and measure them to tell them apart. [02:31.72]"It's not very accurate," she said. [02:34.80]Schreier said when she and her team catch the fish, [02:40.84]the Sherlock machine is able to quickly tell them [02:44.80]if they have one of the special salmon. [02:49.32]It's important because it allows the scientists to do things [02:54.52]that will help the endangered salmon live longer. [02:59.20]For example, they can catch them in lakes far away from the coast [03:05.12]and take them by truck to the San Francisco Bay. [03:10.16]In the past, the fish might have tried to make it to the Bay [03:15.00]by swimming in rivers. [03:17.60]However, due to climate change, [03:21.44]the river water is sometimes too warm [03:26.04]for the fish to make the trip safely. [03:29.44]Schreier said she feels good about the project [03:33.08]because she likes being able to assist with conservation. [03:38.80]"I really want to work to, you know, maintain [03:44.68]our ecosystems and our native populations [03:49.36]as much as possible, given all of the pressures that we humans [03:52.60]place on them through our different activities." [03:55.56]Melinda Baerwald is an environmental program manager [04:00.64]with the California Department of Water Resources. [04:04.80]She also is working on the study. [04:07.64]She said the work the team is doing on getting information about the fish [04:13.76]is just one example of how new information about genetics [04:19.12]will help people who do work like hers. [04:23.48]"The power of genetics is now unlocked for other people to be able to use. [04:28.44]And that's one of the big things that I think is changing [04:32.36]how we're going to use this in our area for monitoring." [04:36.68]I'm Dan Friedell. [04:38.72]更多听力请访问51VOA.COM