滑雪技巧初学者
Press Relea
2012-10-08
The Nobel Asmbly at Karolinska Institutet has today decided to award
The Nobel Prize in Physiology or Medicine 2012
jointly to
灵沼轩John B. Gurdon and Shinya Yamanaka
for the discovery that mature cells can be reprogrammed
to become pluripotent
Summary
The Nobel Prize recognizes two scientists who discovered that mature, specialid cells can be reprogrammed to become immature cells capable of developing into all tissues of
the body. Their findings have revolutionid our understanding of how cells and organisms develop.
John B. Gurdon discovered in 1962 that the specialisation of cells is reversible. In a classic experiment, he replaced the immature cell nucleus in an egg cell of a frog with the nucleus from a mature intestinal cell. This modified egg cell developed into a normal tadpole. The DNA of the mature cell still had all the information needed to develop all cells in the frog.
火警119Shinya Yamanaka discovered more than 40 years later, in 2006, how intact mature cells in mice could be reprogrammed to become immature stem cells. Surprisingly, by introducing only a few genes, he could reprogram mature cells to become pluripotent stem cells, i.e. immature cells that are able to develop into all types of cells in the body.
The groundbreaking discoveries have completely changed our view of the development and cellular specialisation. We now understand that the mature cell does not have to be confined forever to its specialid state. Textbooks have been rewritten an
d new rearch fields have been established. By reprogramming human cells, scientists have created new opportunities to study dias and develop methods for diagnosis and therapy.
Life –a journey towards increasing specialisation
丹麦美食
All of us developed from fertilized egg cells. During the first days after conception, the embryo consists of immature cells, each of which is capable of developing into all the cell types that form the adult organism. Such cells are called pluripotent stem cells. With further development of the embryo, the cells give ri to nerve cells, muscle cells, liver cells and all other cell types - each of them specialid to carry out a specific task in the adult body. This journey from immature to specialid cell was previously considered to be unidirectional. It was thought that the cell changes in such a way during maturation that it would no longer be possible for it to return to an immature, pluripotent stage.
书本封面
1
Frogs jump backwards in development
John B. Gurdon challenged the dogma that the specialid cell is irreversibly committed to its fate. He
hypothesid that its genome might still contain all the information needed to drive its development into all the different cell types of an organism. In 1962, he tested this hypothesis by replacing the cell nucleus of a frog's egg cell with a nucleus from a mature, specialid cell derived from the intestine of a tadpole. The egg developed into a fully functional, cloned tadpole and subquent repeats of the experiment yielded adult frogs. The nucleus of the mature cell had not lost its capacity to drive development to a fully functional organism.穷睇眄于中天
Gurdon's landmark discovery was initially met with scepticism but became accepted when it had been confirmed by other scientists. It initiated inten rearch and the technique was further developed, leading eventually to the cloning of mammals. Gurdon's rearch taught us that the nucleus of a mature, specialized cell can be returned to an im
mature, pluripotent state. But his experiment involved the removal of cell nuclei with pipettes followed by their introduction into other cells. Would it ever be possible to turn an intact cell back into a pluripotent stem cell?
>宝宝奶瓶
