TOKYO -- Genome editing technology looks set to revolutionize the way scientists develop genetically modified foods and discover new drugs.
Japanese scientists are using this new technology to manipulate genes to produce better fish and agricultural products.
Yasutoshi Yoshiura, a senior researcher at the National Research Institute of Fisheries and Environment of Inland Sea, an arm of Japan's Fisheries Research Agency, has been trying to find ways to breed easier-to-grow tiger puffer fish over the past 7-8 years.
In general, it takes about two years to farm-raise tiger puffers before they are ready for shipment. Yoshiura has been seeking to cut this period by half to one year, which would help lower blowfish prices significantly and make the fish more readily available to consumers.
His research made little headway, until advances in genetic analysis technology enabled him and his fellow researchers to identify the puffer fish's appetite-regulating genes. The conventional methods couldn't ensure improvement of the breed even if the scientists grew more than 10,000 tiger puffers.
Genome editing has changed all that. On a recent day, about 40 tiger puffers were swimming in an aquarium at the institute -- all of them about 20cm in length. "I never imagined that they would grow as fat as this. They weigh 20% more than ordinary puffers," Yoshiura said, looking at the data. His blowfish grew fatter because he used genome editing to turn off the function of appetite-regulating genes.
DNA, located in the nucleus of the cell, is a molecule that contains the organism's design data and a number of genes that produce proteins. In genome editing, scientists use chemical compounds, such as special enzymes and nucleic acids, to genetically modify genes by cutting or replacing targeted DNA parts.
In 2012, two scientists from the U.S. and France published an article about this new gene-altering method in the American scientific journal Science. This has fueled competition to commercialize genome-editing technology. In China, for instance, there have been reports of unusually muscular dogs and small pet pigs produced using this technology.
In spring this year, Yoshiura injected into tiger puffers the chemical compounds that can curb the function of appetite-regulating genes. All the resulting tiger puffers have grown much more than he expected. "Genome editing will become a general-purpose technology and can be used by anyone as long as one has knowledge of biogenetics," he said.
His research partner institutions, Kyoto University and Kinki University, have been studying ways to help stimulate the growth of red sea bream. "We can put that research onto a commercial basis in 3-5 years," he said.
Meanwhile, genome editing can also bring about revolutionary change to the drug discovery process.
With the help of this technology, it takes researchers half the time and less than half the cost to produce laboratory mice. As a result, Atsushi Yoshiki, the head of the Experimental Animal Division at the Riken BioResource Center, has received a flurry of requests for genetically-edited mice from researchers around Japan. This is because the center distributes such mice to research and medical institutions at home and abroad. Using such mice could help expedite drug development for rare diseases.
But there are still various hurdles along the way.
Akihiko Kondo, a professor at Kobe University, has been calling for research grants from the education, science and technology ministry. He thinks Japan should develop its own genome-editing technology to avoid paying exorbitant license fees for overseas intellectual property rights.
Kondo described a case in which a foreign company demanded 10% of sales as a license fee for using its genome editing-related patent. In other words, profits would flow out of Japan to other countries even if Japanese researchers created improved agricultural products or developed new drugs using foreign-patented genome-editing methods.
But there is promise -- he is aiming to use a special enzyme that can replace a part of a genome. If he can realize the technology for sending such an enzyme to the targeted part efficiently, it would enable Japanese scientists to avoid infringing on patents held by world-leading research institutes in genome editing, such as the U.S.-based Broad Institute.
That is why professor Hiroshi Ezura of the University of Tsukuba is using the domestic genome-editing technology developed by Kondo and other researchers, to grow experimental tomatoes. Ezura has altered tomato genes that are related to lasting freshness, and he is getting close to making tomatoes that do not rot easily.
However, Ezura is concerned about consumer reaction. Last year, one of the company officials he worked with said he was worried about a negative impact on his company's reputation. He wanted his name removed from the list of joint researchers.
Genome editing is, in a sense, the ultimate form of gene modification. Japanese consumers are often averse to genetically modified food out of concern for safety. "Setting rules are necessary in order to dispel such concerns," Ezura said.