CRISPR has been used for a variety of agricultural and public health purposes, now a study involving fish finds that CRISPR can be a conservation and resource management tool as well. According to a paper published last week in Molecular Ecology Resources, CRISPR’s ability to rapidly detect and differentiate among species could revolutionize environmental monitoring.
The California-based team found that the CRISPR-based detection platform SHERLOCK (specific high-sensitivity enzymatic reporter unlocking) was able to genetically distinguish threatened fish species from similar-looking nonnative species in nearly real time, with no need to extract DNA.
"CRISPR can do a lot more than edit genomes," said co-author Andrea Schreier. "It can be used for some really cool ecological applications, and we're just now exploring that."
The scientists focused on three fish species of management concern in the San Francisco Estuary: the U.S. threatened and California endangered Delta smelt, the California threatened longfin smelt and the nonnative wakasagi. These three species are notoriously difficult to visually identify, particularly in their younger stages.
"When you're trying to identify an endangered species, getting it wrong is a big deal," said lead author Melinda Baerwald.
Typically to accurately identify the species, researchers rub a swab over the fish to collect a mucus sample or take a fin clip for a tissue sample. Then they drive or ship it to a lab for a genetic identification test and await the results. Not counting travel time that can take, at best, about four hours. SHERLOCK shortens this process from hours to minutes. Researchers can identify the species within about 20 minutes, at remote locations, noninvasively, with no specialized lab equipment. Instead, they use either a handheld fluorescence reader or a flow strip that works much like a pregnancy.
"Anyone working anywhere could use this tool to quickly come up with a species identification," Schreier said.