摘要：蠕虫的太空飞行可以消除太空飞行对人类健康的严重威胁，英国诺丁汉大学的蠕虫乘坐太空飞船阿特兰蒂斯号，飞向200多英里以外在的国际空间站并滞留在轨道上11天。此外，专家把秀丽隐杆线虫（线虫）作为模式生物，记录疾病和衰老过程中肌肉衰退各细节。
多达20 000个线虫基因与人类基因执行相同的功能，因此，线虫可用于研究太空飞行给宇航员造成的肌肉损害。已有证据表明：RNAi干扰技术在病变组织调控基因表达，而关键问题是该技术能否缓解宇宙射线引起的严重肌肉损伤。
转化荧光载体和RNAi干扰的线虫
A space flight by millions of microscopic worms could help us overcome the numerous threats posed to human health by space travel. The Caenorhabditis elegans (C. elegans) have also given experts an insight into how to block muscle degradation in the sick and elderly.
The worms -- from The University of Nottingham -- were flown into space onboard the Space Shuttle Atlantis. They spent 11 days in orbit onboard the International Space Station more than 200 miles above Earth.
Many of C. elegans' 20,000 genes perform the same functions as those in humans. Experts in human physiology from the School of Graduate Entry Medicine wanted to study the effectiveness of RNA interference (RNAi), a tried and tested technique which regulates gene expression in diseased tissue, and whether this technique could be employed to reduce or control the dramatic muscle loss experienced by astronauts during spaceflight.
The results of this research, published June 1, 2011 in the journal PLoS ONE, have shown that RNAi, which is already the subject of more than a dozen clinical trials to target illnesses ranging from cancer to asthma, functions normally in space flight and could be used as a viable option to treat and control muscle degradation in spaceflight. Their discovery will not only be of interest to astronauts but will also help people who suffer from muscle wasting caused by illness and old age.
Dr Nathaniel Szewczyk from the Division of Clinical Physiology said: "It was really a quite straightforward experiment. Once the worms were in space the scientists onboard the International Space Station treated them with RNAi and then returned them to us for post flight analysis. These results are very exciting as they provide a valuable experimental tool for spaceflight research and clearly demonstrate that RNAi can be used effectively to block proteins which are needed for muscle to shrink."
During the flight a series of experiments were carried out by Japanese scientists onboard the International Space Station. When the flight samples were returned to Nottingham the results were analysed by Dr Timothy Etheridge, in the Division of Clinical Physiology.
Timothy Etheridge said: "We were very pleased that, given the numerous problems associated with conducting research in space, our experiments went as planned and allowed us to demonstrate that this form of gene therapy works effectively during spaceflight. The unexpected finding that RNAi can effectively block protein degradation in muscle in space was also a very welcome surprise."
The experiment was part of the Japanese CERISE payload and funded as parts of a $1m (£0.6m) United States National Institute of Health grant to investigate the genetic basis of muscle atrophy and a £0.5m Medical Research Council grant to investigate how physical forces prevent muscle wasting.
The recently installed Kibo lab is being used for the study of biomedicine and material sciences making use of the weightless conditions experienced in orbit.
Biological experiments in space need life support -- oxygen, temperature control and pressure -- so competition for space on manned flights is fierce and in short supply.
The origins of Dr Szewczyk's worms can be traced back to a rubbish dump in Bristol. C. elegans often feed on bacteria that develop on decaying vegetable matter.
