exogenous

　芽に毒を含まないジャガイモを作る研究が進められています。

Genome editing used to cut toxins in potatoes

A team of researchers has developed a method to commercialize potatoes that are free from toxic compounds in their sprouts and other parts, by using genome-editing technology that modifies targeted genes.

The team comprises mainly researchers from RIKEN and Osaka University. It plans to start outdoor test cultivation as early as next fiscal year, and hopes to commercialize the vegetables within five years.

The study results were presented at a meeting of the Japanese Society for Genome Editing in Hiroshima on Wednesday.

The most common genome-editing method to improve varieties is to introduce artificially created exogenous genes into cell nuclei to modify the crop’s genes. However, some researchers have said that such crops will destroy biodiversity if they are crossbred with other wild species.

以下省略

http://the-japan-news.com/news/article/0004528594

　exogenous /eksάdʒənəs/ を取り上げます。genousという言葉が含まれていることから、遺伝に関連することはわかりますが、予想が難しかったので早速調べてみました。手持ちの紙辞書には記載がありませんでしたが、電子辞書の『ジーニアス英和辞典』（第4版　研大修館書店）には「（医）外因的な；（生）外生の、外因性の」とありました。

　Merriam- Websterには “produced by growth from superficial tissue” や “introduced from or produced outside the organism or system; specifically : not synthesized within the organism or system” などと定義されています。

日本語ではどのような意味になるのか、日本語版の記事を探すとexogenous genesは「外来遺伝子」という意味になることが確認できました。（aqua）