英语演讲PPTSyntheticcell人造生命.pptVIP

* On May 22nd 2010, J. Craig Venter announced the first synthetic cell, a cell made by starting with the digital code in the computer, building the chromosome from four bottles of chemicals, assembling that chromosome in yeast, transplanting it into a recipient bacterial cell and transforming that cell into a new bacterial species. They thought if this is supposed to be the smallest genome of a self-replicating species, could there be even a smaller genome? Could they understand the basis of cellular life at the genetic level? Before they did the first experiment, they actually asked Art Caplans team, then at the University of Pennsylvania, to undertake a review of what the risks, the challenges, the ethics around creating new species in the laboratory were because it hadnt been done before. They spent about two years reviewing that independently and published their results in Science in 1999. In 2002, they started a new institue, the Institute for Biological Energy Alternatives, where they set out two goals. Their first task was a 5,000-letter code bacteriophage, a virus that attacks only E.coli. So that was the phage X174, which was chosen for historical reasons. It was the first DNA phage, DNA virus, DNA genome that was actually sequenced. They had to solve the chemistry for making large DNA molecules, and they had to solve the biological side of how, if they had this new chemical entity, how would they boot it up, activate it, in a recipient cell. In 2007, Carole Lartigne led the effort to actually transplant a bacterial chromosome from one bacteria to another. Both sides were progressing, but part of the synthesis had to be accomplished or was able to be accomplished, using yeast, putting the fragments in yeast, and yeast would assemble these for them. Their team developed new techniques for actually growing, cloning entire bacterial chromosome in yeast. They found if they took the chromosome out of yeast and methylated it, they could then transplant