First Organism With Artificial DNA Debuts

摘要

A chimera, in Greek mythology, is a creature made from parts of different animals - an alien monster. That's how some might view the organism created by a team at Scripps Research Institute in California. Expanding upon DNA's complement of four chemical nucleotides, or "letters" (A, T, C and G), the scientists concocted a totally unnatural pair of nucleotides, dubbed X and Y. As reported in Nature in May, the team inserted the two into a bacterial cell, a strain of E. coli. When the cell reproduced, unwinding its double helix and reconstituting it in new cells, X and Y replicated as well, their chemical bond just as stable as the A-T and C-G pairings in DNA's normal sequence.