基因鼠 mighty mouse 的啟示

大概在17年前 我當時任職的Du Pont公司申請一隻基因鼠的專利

過數年公司將21世紀的口號訂為
The Miracles of Science.......

2007.11.02 • 14:38 EST

Behold the genetically engineered mighty mouse!

In news sure to shiver exterminators everywhere, scientists at Case Western Reserve University have created a super mouse. A mighty mouse! And not just one -- 500 of them! As a result of genetic engineering that boosts the level of an important skeletal muscle enzyme, these little buggers are markedly more active, more aggressive, fitter, and can breed and live longer than ordinary mice.

Whereas a regular rodent can't last an hour on a treadmill -- a cute little mousey treadmill, naturally, not one you find at Gold's -- the super mice can run five or even six hours at 20 meters per minute. An ordinary female mouse can't have any baby mice after she's about a year old, but the mighty mice can reproduce well past age 2.

Richard Hanson, a biochemistry professor who developed the mice with the help of his mousey grad students, offers this quotable quote in a press release: "They are metabolically similar to Lance Armstrong biking up the Pyrenees; they utilize mainly fatty acids for energy and produce very little lactic acid."

The engineered mice have very high levels of an enzyme called phosphoenolpyruvate carboxykinase, or PEPCK-C. Ordinary mice have only 0.08 units of PEPCK-C per gram of skeletal muscle -- super mice have an amazing 9 units per gram.

As a result, their metabolisms are through the roof. And when exercising, super mice rely on fatty acids for their fuel, while ordinary mice use carbohydrates, which raises the level of lactic acid in their blood.

Alas, the researchers say they're not going to do the same thing in humans. "The ethical implications are such that this approach should not be used in humans, or is it technically possible at this time to efficiently introduce genes into human skeletal muscle, in order to mimic the effect seen in our mice," Hanson says. One wonders if the Defense Department feels the same way. (Or maybe the DoD will just use super mice to go after Iran?)

The mouse study is published in the Journal of Biological Chemistry.

Here's a video of the super mouse in action. The mouse in the back is an ordinary rodent -- watch how quickly he conks out, while the enzymey mouse in front keeps going.

【聯合報╱編譯王先棠╱報導】 2007.11.03 03:07 am

老鼠也能跑馬拉松。美國學者透過基因工程成功繁殖出能連續跑六個小時不用休息的「威力鼠」（mighty mouse）。學者表示，這種威力鼠的相關研究，可以促進新藥研發，甚至藉此強化運動員的體能。 參與研究的俄亥俄州凱斯西儲大學生物化學教授韓森說，威力鼠能以每分鐘廿公尺的速度連續跑六個鐘頭，一天能跑六公里。 威力鼠體內新陳代謝機制極佳，以消耗脂肪酸的方式產生能量。由於體內產生的乳酸極少，這種老鼠的肌肉不容易有疲累感，好比在環法自由車賽七連霸的阿姆斯壯在庇里牛斯山區騎車，一馬當先。 學者說，「威力鼠」計畫在探索一種名為PEPCK-C的酵素在肌肉與細胞組織中的代謝功能。 學者修改了老鼠的基因，使基改鼠體內產生大量的PEPCK-C，這種酵素的增加，顯然提高了老鼠體內脂肪轉換成能量的效率。韓森說：「就算不吃不喝，它們還是能連續跑四或五個小時。」 英國每日郵報指出，四年前研究人員就成功創造出第一隻威力鼠，但是直到最近才在「生物化學期刊」公布成果。研究人員至今總共繁殖了五百隻。 新型基改鼠的食量比實驗控制組中的野生老鼠多百分之六十，體重是一般老鼠的一半，吃再多仍能保持苗條，活動力是一般家鼠的十倍。 一般老鼠平均壽命是兩年，這種基改鼠能活三年。基改母鼠的生育期也比其他老鼠長，普通老鼠一歲之後就不再生育，但母的基改鼠到兩歲半仍能生小鼠。 更大的驚奇是威力鼠的誕生，來自研究團隊運用標準基改技術處理老鼠體內單一的新陳代謝基因，人類也有相同的基因。