From Bio Journal - April 2022

Development of genome-edited chickens moves forward in the world and in Japan

In November last year, NRS Poultry, a company based in Israel and the US, made it possible using genome editing technology to produce chickens that lay eggs in which the eggs of males do not hatch but the eggs of females are not affected. This technology is causing quite a stir.

Up to now, all male chicks hatched from egg-laying chickens have been culled. This was criticized as being in conflict with animal welfare, and the culling of male chicks was banned in Germany from January 1, 2022. To solve this problem, genome-editing technology has been used to manipulate the Z chromosome, a unique bird chromosome, to prevent male chicks only from hatching. This is creating a trend in Europe to expand the ban on culling male chicks.

At the same time, this could also affect trends in genome-edited food in Europe, since the eggs are likely to be exported to Europe. With these eggs as an excuse, there is a move in the European Commission to allow the distribution of genome-edited foods without risk assessment or labeling. The reason given is that the genes used for the genome editing of the hen that lays these eggs do not remain in the hen.

The UK has also made a behind-the-scenes decision to abandon its mechanisms for protecting the environment and food safety by excluding genome editing from GMOs, and is moving to promote genome-edited foods.

Similar studies of chickens are also being conducted in Japan. A research team led by Hiroyuki Horiuchi of Hiroshima University is using genome-editing technology to produce chickens that are genetically modified to become females. The plan is to destroy the male genes that make up the germ cells such that all the chickens that are born become females.

Other attempts to develop genome-edited chickens are also underway in Japan. The first to be developed was the "ovomucoid gene-deleted chicken," which prevents the production of ovomucoid protein, an allergen found in egg white, by a research team at the livestock research department of the National Agriculture and Food Research Organization (NARO). Using genome-editing techniques, the ovomucoid gene was firstly destroyed in the cells that are to become male germ cells, which were then hybridized with females to produce the "ovomucoid gene-deleted chicken." It is in these ways that the application of genome-editing technology to chickens is becoming increasingly active in Japan as well as overseas.

Development of hypoallergenic wheat using genome editing at Yokohama City University

With a target of the end of March 2022, a team of researchers under associate professor Kanako Kawaura of Yokohama City University's Kihara Institute for Biological Research is developing hypoallergenic wheat using genome editing technology. The research aims to knock out the genes related to gliadin, a component of gluten, a protein that causes wheat allergies.

Tokushima University venture company develops hypoallergenic crickets

Gryllus, a Tokushima University venture company that has developed fast-growing crickets using genome-editing technology, announced on February 28 that it had raised 290 million yen and would develop hypoallergenic crickets during 2023. Thus far, native Japanese crickets and two-spotted crickets have been developed as edible crickets, and the plan is to develop hypoallergenic crickets from these two cricket types. (Gryllus 2022/3/1)

Demand to withdraw the use of genome-edited pufferfish as a Miyazu City hometown tax return gift

A citizens' group known as "Mugi no Nechu Fu Nettowa-ku" requested the mayor of Miyazu City, Kyoto Prefecture, to cease using the city's genome-edited pufferfish as a return gift for hometown tax donations. It also asked Regional Fish, a company which farms gene-edited pufferfish and red sea bream in the city, to hold a briefing and not to farm the genome-edited fish in the sea. (Mainichi Shimbun 2022/2/22)

RIKEN develops novel gene expression technology

A research team at the Institute of Physical and Chemical Research (RIKEN) has developed a technology that causes plants (Arabidopsis thaliana) to express foreign genes by spraying the plants with DNA and RNA entrapped in nanoparticles. Details have been published in ACS Nano (February 23, 2022). The team, led by Chonprakun Thagun of the Biopolymer Research Team at the RIKEN Research Center for Environmental and Resource Sciences, developed the system. Sprayed DNA is said to produce a protein derived from that DNA, and since the action of the DNA is of a transient nature it is not integrated into the genome as in genetic recombination. Sprayed RNA suppresses the action of the target gene by the action of the RNA, which is a commonly used RNA interference method. (Institute of Physical and Chemical Research, RIKEN)

Development of Designer Cells as Pharmaceuticals

In addition to conventional medical treatment using chemical substances and genes, as medical treatment using cells is also anticipated to advance, the development of designer cells for use in treatment is becoming very lively. Regenerative medicine has thus far mainly utilized stem cells and iPS cells, but in contrast cell therapy uses cells that have been artificially modified as pharmaceuticals. Cells that have been modified using engineering techniques are been used, for example, in attempts destroy cancer cells. (Nikkei Biotech Online 2022/3/18)

Development of biofloc technology for onshore culture of genetically modified fish

There is an active movement toward the development of land-based aquaculture, since the risk of escape into the environment is low, making it ideal for the cultivation of genetically modified or genome-edited fish. Especially, low-cost biofloc technology is gaining attention. Biofloc uses a floating mass of microbes placed in a culture pond that creates a water flow. This requires oxygen to be supplied but no extra water supply. However, as suspension is unavoidable, the technology is limited to fish that can tolerate suspension, and thus tilapia and vanamei (whiteleg) shrimp are currently being cultivated using this method. Regional Fish Co., which develops genome-edited fish, has announced that it will start a demonstration experiment to find an optimal culture method for vanamei shrimp together with NTT DOCOMO, Okumura Corporation, and Iwatani Corporation, and will be responsible for the development of the biofloc method and genome-editing technology.

Cabinet approves revision of law to simplify drug safety assessment

On March 1, the cabinet has approved a bill to revise the Pharmaceutical and Medical Device Act, allowing for the approval of pharmaceuticals in emergency situations. This raises the possibility that the bill will be passed in the current Diet session. If enacted, the act will allow pharmaceuticals to be approved in an emergency without the implementation of a phase III clinical trial. This amounts to a simplification of safety testing and is a decision that could jeopardize the safety of pharmaceuticals and vaccines.

Convention on Biological Diversity COP15 meetings of subsidiary bodies held

In response to the delay in holding the face-to-face plenary session of the Conference of the Parties to the Convention on Biological Diversity (COP15), which is scheduled to be held in China, meetings of the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA), the Subsidiary Body for Implementation of the Convention (SBI), and the Open-ended Working Group (OEWG) were held in Geneva, Switzerland. A final draft of indicators for the new 2020 target for the post-Aichi Biodiversity Framework, and resource mobilization and financial mechanisms to enable its implementation were compiled. COP15 is scheduled to be held in Kunming, China, from July to September.

Note: External links provided for the information of users in no way imply CBIC endorsement for views expressed in those websites, nor is CBIC in any way responsible for the content of external Internet sites.

(English Index)