Francis S. Collins and J. Craig Venter

A decade after the human-genome project, biological science is poised on the edge of something wonderful

Ten years ago, on June 26th 2000, a race ended. The result was declared a dead heat and both runners won the prize of shaking the hand of President Bill Clinton. The runners were J. Craig Venter for the private sector and Francis Collins for the public. The race was to sequence the human genome, all 3 billion genetic letters of it, and as headline writers put it – read the book of life.

There was the drama of a maverick upstart, in the form of Dr Venter and his newly created firm, Celera, taking on the medical establishment, in the form of Dr Collins’s International Human Genome Sequencing Consortium. There was the promise of a cornucopia of new drugs as genetic targets previously unknown to biologists succumbed to pharmacological investigation. There was talk of an era of “personalized medicine” in which treatments would be tailored to an individual’s genetic make-up.

As The Economist observed at the time, the race Dr Venter and Dr Collins had been engaged in was a race not to the finish but to the starting line. Moreover, compared with the sprint they had been running in the closing years of the 1990s, the new race marked by that starting line was a marathon. The competitors ran into numerous obstacles. They found at first that there were far fewer genes than they had expected, only to discover later that there were far more. These discoveries changed the meaning of the word “gene”. They found the way genes are switched on and off is at least as important, both biologically and medically, as the composition of those genes. They found that their methods for linking genetic variation to disease were inadequate. And they found, above all, that they did not have enough genomes to work on. Each human genome is different, and that matters.

One by one, however, these obstacles are falling away and the science of biology is being transformed. It seems quite likely that future historians of science will divide biology into the pre- and post-genomic eras. In one way, post-genomic biology – biology 2.0, has finally killed the idea of vitalism, the persistent belief that to explain how living things work, something more is needed than just an understanding of their physics and chemistry. So it is with the new biology. The chemicals in a cell are the hardware. The information encoded in the DNA is the preloaded software. The interactions between the cellular chemicals are like the constantly changing states of processing and memory chips. Though understanding the genome has proved more complicated than expected, no discovery made so far suggests anything other than that all the information needed to make a cell is squirreled away in the DNA. Yet the whole is somehow greater than the sum of its parts.

The past few weeks have seen an announcement that may turn out to have been as portentous as the sequencing of the human genome: Dr Venter’s construction of an organism with a completely synthetic genome. The ability to write new genomes in this way brings true biological engineering – as opposed to the tinkering that passes for biotechnology at the moment – a step closer. A second portentous announcement, of the genome of mankind’s closest – albeit extinct -relative, Neanderthal man, shows the power of biology 2.0 in a different way. Putting together some 1.3 billion fragments of 40,000-year-old DNA, contaminated as they were with the fungi and bacteria of millennia of decay and the personal genetic imprints of the dozens of archaeologists who had handled the bones, demonstrates how far the technology of genomics has advanced over the course of the past decade. It also shows that biology 2.0 can solve the other great question besides how life works: how it has evolved and diversified over the course of time.

As is often the way with scientific discovery, technological breakthroughs of the sort that have given science the Neanderthal genome have been as important to the development of genomics as intellectual insights have been. The telescope revolutionized astronomy; the microscope, biology; and the spectroscope, chemistry. The genomic revolution depends on two technological changes. One, in computing power, is generic – though computer-makers are slavering at the amount of data that biology 2.0 will need to process, and the amount of kit that will be needed to do the processing. This torrent of data, however, is the result of the second technological change that is driving genomics, in the power of DNA sequencing.

Eric Lander, the head of the Broad Institute, in Cambridge, Massachusetts, which is America’s largest DNA-sequencing center, calculates that the cost of DNA sequencing at the institute has fallen to a hundred-thousandth of what it was a decade ago. The genome sequenced by the International Human Genome Sequencing Consortium took 13 years and cost $3 billion. Now, using the latest sequencers from Illumina, of San Diego, California, a human genome can be read in eight days at a cost of about $10,000. Another Californian firm, Pacific Biosciences, of Menlo Park, has a technology that can read genomes from single DNA molecules. It thinks that in three years’ time this will be able to map a human genome in 15 minutes for less than $1,000.

Even before cheap sequencing became available, huge databases were being built up. In alliance with pathology samples, doctors’ notes and – most valuable of all – long-term studies of particular groups of individuals, genetic information can be linked to what biologists refer to as the phenotype. This is an organism’s outward expression: its anatomy, physiology and behavior, whether healthy or pathological. The goal of the new biology is to tie these things together reliably and to understand how the phenotype emerges from the genotype. That will lead to better medical diagnosis and treatment. It will result in the ability to manipulate animals, plants, fungi and bacteria to human ends and it may help to explain the history of life and what it is to be human. Source: by Geoffrey Carr, The Economist (US). Economist Newspaper Ltd. 2010

Comments

Leave a Reply

You must be logged in to post a comment.