June 24, 2010

10 Years Of The Human Genome

It has been ten years since the human genome was first sequenced, and in the time since, there have been many great findings in understanding the origins and evolution of mankind.

"With this profound new knowledge, humankind is on the verge of gaining immense, new power to heal. It will revolutionize the diagnosis, prevention and treatment of most, if not all, human diseases." So declared then US President Bill Clinton on June 26, 2000, at an event held to hail the completion of the first draft of the human genome sequence by two fierce rivals, the publicly funded international Human Genome Project and its private-sector competitor Celera Genomics of Rockville, Maryland.

Tens of billions of dollars were spent on genomics research since the landmark event, but the genome has yet to deliver a revolution against human disease, and a poll of more than 1,000 life scientists shows that most do not anticipate that it will for decades to come.

What the sequencing has done, though, is bring about a revolution in biology. It has transformed the professional lives of scientists, inspiring them to tackle new biological problems and take on new challenges along the way.

In 2002, following the first draft of the human genetic code, scientists at the International HapMap Project began mapping genes and identifying those which were involved in complex disease.

The effort also began shedding light on the movements of early humans, which migrated out of Africa some 50,000 years ago reaching every corner of the globe.

Collecting DNA samples over the past ten years, researchers have studied the genetic makeup of more than 3,000 individuals from 121 populations in Africa, four African-American communities and 60 non-African groups including Europeans.

According to a study published last year, geneticists determined that the genetic diversity of Africans is higher than any other population in the world. They were even able to confirm the origins of modern man emerging out of Africa, specifically from the region between South Africa and Namibia.

Comparing sequences of the Neanderthal genome and modern humans has also confirmed interbreeding between both species.

"The Neanderthal genome sequence allows us to begin to define all those features in our genome where we differ from all other organisms on the planet, including our closest evolutionary relative, the Neanderthals," said Svante Paabo, director of the genetics department of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

Research published in the United States in early June revealed the distinct genetics of the Jewish Diaspora, according to its unique genome.

"We have shown that despite the fact that individuals from the Diaspora have distinctive features that are representative of each group's genetic history, they also share a set of common genetic threads," said Harry Ostrer, professor of Medicine at New York University, at the time.

Great potential for further discoveries using genome maps lies with a dramatic decline in the cost of sequencing since the early days, say scientists. California companies Illumina and Life Technologies can now do the job in a single day for around $6,000.

The decline in the price has enabled scientists to peer into the DNA maps of a whole range of non-human species. They have mapped the genomes of more than 3,800 organisms.

In a poll conducted by Nature, 69 percent of scientists who responded to the survey said that human genome projects inspired them either to become a scientist or to change the direction of their research. 90 percent said that their own research has benefited from human genome sequencing, with 46 percent saying it has done so "significantly."

A third of scientists said they use sequencing "almost daily" in their research. "For young researchers like me it's hard to imagine how biologists managed without it," wrote one scientist.

The survey also revealed how researchers are confronting the increasing availability of information about their own genomes. Some 15 percent of respondents said that they have taken a genetic test in a medical setting, and almost one in ten has used a direct-to-consumer genetic testing service.

When asked what the scientists would sequence if they could sequence anything, most listed their own genomes, their children or those of other family members. Some also listed pet cats and dogs.

Nature's poll also weighed out where the sequence has had the greatest impact on the science itself. Although nearly 60 percent of those polled said they thought that basic biological science had benefited significantly from human genome sequences. About 20 percent felt the same was true for clinical medicine.


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