Genetically engineered (GE) CRISPR/Cas fish are being marketed as food in Japan. The technology was used to block gene functions which regulate the growth of muscles in red seabream. The fish consequently showed higher muscle mass, a larger body, a reduction in body length and vertebrae in an abnormal position. In comparison to the wild type, the fish gain weight faster and appear to move more slowly.

No data are available to show how the genetic alteration affects the life span or health of the fish in general. There also seem to be no data available on animal welfare. In addition, there are no answers to questions about changes in the composition of the flesh of the GE fish or the potential impact on consumers.

At a technical level this shows that the genetic intervention was not precise: the researchers started with hundreds of GE fish from which they selected those which seemed to be suitable for further breeding. The targeted gene sites showed differing alterations. Furthermore, in many cases, the genes were altered in some organs, but not in all cells of the body.

On a socioeconomic level it appears that developments were mostly driven by profit: it is assumed that costs for feeding the GE fish reared in special containers can be lowered. Scientists involved in the project are also named in patent applications being filed on the usage of gene scissors in fish. A Japanese company has started to market the fish via a specific website.

Japanese authorities assume that GE organisms, such as tomato and fish, do not carry any specific risks as long as no additional genes are inserted. However, this assumption ignores the fact that interventions using gene scissors can result in highly complex genetic changes simply by blocking natural gene functions. In addition, the processes of genetic engineering also cause unintended side effects and genetic alterations.

This example shows: Applications of New Genetic Engineering techniques can result in plants and animals with extreme biological characteristics, which go beyond what can be achieved in conventional breeding. Without mandatory approval processes and a prospective technology assessment, more and more genetically engineered plants and animals may enter the market without having undergone detailed risk assessment; they may also have questionable traits from an ethical perspective. It would mean paving the way for ‘progress’ to go in the wrong direction – with serious consequences for humans, animals and the environment.

Publication year: 
2021

Further information: 
Publication on GE Seabream
Testbiotech news on approval of the GE seabream in Japan