少し前のことになるが、9月の上旬に、愛読しているメルマガ’HortiBiz’に、”Japan: CRISPR used to alter flower color”という記事が転載されていた。筑波大学の研究者チームが、朝顔の色を変える技術を開発したという知らせである。
わが家の二階のベランダには毎朝、100個ほど朝顔が咲いている。色鮮やかと言いたいところだが、深い青色と浅いブルーと、うすい白の混じった紫色の三色。一階のプランターから麻のネットの梯子を伝って、10メートルほど上に這い上ってくる。
毎夏のことだ。いつも種をまくのが遅いのか、わが家の朝顔は開花の期間が長い。しかし、遅い夏の名残りを惜しむように咲き誇っている朝顔も、そろそろつるが伸びきって夏が終わる。
残念ながら、この記事のように、白色の朝顔にはお目にかかったことがない。自然が600年をかけて実現した白色の朝顔（1600年代江戸初期の日本）を、科学者が一年で実現してしまった。
う～ん、ロマンがないのか？人間の手が実現してしまうのだから、それもサイエンティストにとってはロマンなのか。。。
“Japan: CRISPR used to alter flower color”
Researchers in Japan have reported in a new study they used the gene editing technology CRISPR to alter the color of a Japanese morning glory, a popular garden flower.
The Japanese morning glory is one of two plants already being studied as part of Japan’s National BioResource Project, so researchers at the University of Tsukuba had a significant body of genomic data to work with.
The Tsukuba research team was able to identify a single gene, dihydroflavonol-4-reductase-B, responsible for the production of the enzyme anthocyanin biosynthesis, which determines the color of the morning glory’s stems, leaves and flowers.
CRISPR technology allows researchers to directly inject an organism with genetic material designed to seek out and rewrite specific portions of DNA coding.
Because dihydroflavonol-4-reductase-B is sandwiched by two similar and related genes, DFR-A and DRF-C, it had to be especially precise with their CRISPR targeting technology.
In CRISPR, an enzyme, Cas9, is programmed to cut the target DNA and delete the code or splice in new code. Guide RNA, or gRNA, helps Cas9 locate the exact DNA target.
Scientists used the plant bacterium Rhizobium to smuggle the CRISPR components into morning glory plant embryos.
When researchers sequenced the genes of the transgenic plants, they found the CRISPR technology had successfully disrupted the DFR-B gene and disabled the enzyme in 75 percent of the plants, yielding flowers with an absence of pigment. The technology turned the morning glories from purple to white.
The analysis also showed the neighboring genes, DFR-A and DFR-C, were undisturbed by the gene-editing technology.
Researchers recounted their success in new paper published this week in the journal Scientific Reports.
The findings are reminder of the power of the CRISPR technology.
”The story of the Japanese morning glory started in the 8th century AD, with the introduction of wild blue-flowered plants into Japan from China,” researchers wrote in a press release. “In 1631, the first white-flowered Japanese morning glory was painted in Japan.”
What took nature 850 years to accomplish, scientists tackled in less than a year.
Click here to read the original article at UPI.
09/06/2017 – United Press International
