Urban Legend 1011: "Fishberry" Ever Existed?

The goals were to extend the growth of vegetables in Alaska and to reduce cold damage on fruits in storage. The idea was to use the anti-freeze protein gene (AFP) from an arctic flounder and insert it into the plants to adjust their sensitivity to freezing conditions. Then, the story began to circulate. People were concerned that they might be eating some gruesome "Fishberry" without knowing. Should the public worry? The answer is "No".

This gene transfer project never produced true anti-freeze plants. The experiment was conducted on corn by Dr. Fawzy Georges in Canada in 1990. The team successfully synthesized this gene and joined it to transfer plasmids. They sent these modified plasmids through the DNA impermeable cell membrane by electroporation. They made corn protoplasts produce AFP; however, the injected AFP failed to enter and protect plant's intercellular spaces due to the lack of required transport signaling DNA sequence.

Another misunderstood point is the transplant method. Although genetic code is universal in all life forms on earth; a "codon bias" exists between plant and animal species. The AFP gene experimented on plants was chemically synthesized based upon the genetic sequence of the flounder gene. Thus, the gene was not physically “extracted from a fish”; only the genetic data was taken.

In addition, strawberry was never a test subject for this research. Only a bacteria, Frostban, was successfully engineered to protect strawberries from frost damage.

In conclusion, "Fishberry" is completely fictional and never existed outside of the minds of enthusiastic researchers.

Posted By Cheng-Hsuan Chang

Primary References:

Fish-Gene Strawberries and Tomatoes. Public Issues Education Project: Genetically Engineered Organisms. (accessed 29/05/07)

J.H. Simonson 1994. Flounder Antifreeze for Plants: Article #1166. Alaska Science Forum. (accessed 29/05/07)

Secondary References:

Hightower R, Baden C, Penzes E, Lund P, and Dunsmuir P. 1991. Expression of antifreeze proteins in transgenic plants. Plant Molecular Biology 17: 1013-1021.

DeVries AL & Wohlschlag DE. 1969. Freezing resistance in some Antarctic fishes. Science 163: 1073-1075.

Davies PL & Sykes BD. 1997. Antifreeze proteins. Current Opinion in Structural Biololgy 7:828-834.

Kenward KD, Brandle J, McPherson J, and Davies PD. 1999. Type II fish antifreeze protein accumulation in transgenic tobacco does not confer frost resistance. Transgenic Research 8:105-117.