Synthetic biology is the study and technology of living systems that incorporate genetic circuits, artificial enzymes, or other cellular components designed by humans to perform certain functions. It builds on sophisticated advances in genetic engineering (recombinant DNA technology) and molecular biology, and technologies for rapidly sequencing DNA and RNA molecules, and for synthesizing novel sequences of DNA and RNA inexpensively on demand. Synthetic biology investigations create cells and cellular products with tremendous potential for improving energy production, pharmaceutical manufacturing, chemical synthesis, new materials discovery, and a wide variety of other technologies. In the process, it can also better illuminate how naturally occurring biological systems work. See also: Genetic engineering; Molecular biology; Recombination (genetics)
One difference between synthetic biology and the genetic engineering efforts that biotechnologists have made since the 1970s involves the scope of the manipulations of the organisms' DNA. Genetic engineers have traditionally made fairly limited modifications of one or at most a small number of genes—for example, changing a gene so that it might become active in the presence of a specific chemical signal or altering a cell so that it made a protein it lacked in nature. In contrast, synthetic biology typically alters an entire suite of interacting genes so that a cell displays a well-controlled set of responses or behaviors across a range of circumstances. Synthetic biologists refer to the genomic constructions that make such programming possible as genetic circuits, which they may assemble from sets of highly well-characterized genomic elements. The Bio-bricks developed by Tom Knight at the Massachusetts Institute of Technology and others represent one such set of standard components commonly used in synthetic biology.
Synthetic biology programs can also embrace even more dramatic departures from natural biological systems. Some researchers have worked on creating entire synthetic chromosomes, which could potentially serve as vectors for introducing extensive synthetic genetic circuitry into organisms and helping to ensure that they would be transmitted between generations. (Botanical investigators have already engineered minichromosomes in certain plants, for example, for experimental study.) Others are studying the possible use of synthetic heredity molecules that emulate DNA but which consist of nucleotide subunits not found in nature, and which might help science understand what extraterrestrial life with profoundly exotic biochemistries might be like. See also: Engineered minichromosomes in plants; Synthetic heredity molecules emulate DNA
One pioneer in synthetic biology is J. Craig Venter, the scientist whose work at The Institute for Genomic Research helped to accelerate the completion of the human genome project and who later founded the genomics company Celera. His research group at the J. Craig Venter Institute created a line of living cells dubbed Synthia that had a genome assembled entirely artificially. Synthia's creators called it the first example of synthetic life—a claim that some other scientists disputed on the grounds that its genes were modeled after those of the natural bacterium Mycoplasma genitalium, not invented from scratch. See also: Genomics; Human genome
Another important figure in the world of synthetic biology is George Church, a molecular geneticist at Harvard University and the director of the Genomes to Life Center at the Pacific Northwest National Laboratory in Richland, Washington. Church, an early proponent of the human genome project, has used his genetics expertise to develop many techniques and tools widely employed by synthetic biology researchers. He is involved with many biotech, genomics, and synthetic biology startup companies.