Resumen de Synthetic life.
The article focuses on the development of new technology that combines genetic engineering and synthetic biology. Scientists are designing and building living systems that behave in predictable ways, that use interchangeable parts, and in some cases that operate with an expanded genetic code. This nascent field has three major goals: One, learn about life by building it, rather than by tearing it apart. Two, make genetic engineering worthy of its name. And three, stretch the boundaries of life and of machines until the two overlap to yield truly programmable organisms. The recent buzz growing around synthetic biology arises from its technological promise as a way to design and build machines that work inside cells. Two such devices, reported simultaneously in 2000, inspired much of the work that has happened since. Both devices were constructed by inserting selected DNA sequences into Escherichia coli, a normally innocuous bacterium in the human gut. The two performed very different functions, however. Michael Elowitz and Stanislaus Leibler, then at Princeton University, assembled three interacting genes in a way that made the E. coli blink predictably, like microscopic Christmas tree lights. Meanwhile James J. Collins, Charles R. Cantor and Timothy S. Gardner of Boston University made a genetic toggle switch. A negative feedback loop--two genes that interfere with each other--allows the toggle circuit to flip between two stable states. It effectively endows each modified bacterium with a rudimentary digital memory. Synthetic biologists have so far built living genetic systems as experiments and demonstrations. But a number of research laboratories are already working on applications. Martin Fussenegger and his colleagues at ETH Zurich have graduated from bacteria to mammals. But synthetic biologists are mainly interested in building genetic devices within living cells, so that the systems can move, reproduce and interact with the real world. INSET: Life, but Not (Exactly) as We Know It.
