How do scientists decide which animal genome to sequence next?

Answers to your questions about the news.
July 17 2009 2:58 PM

The Sequence of Sequencing

How do we decide which genome to map next?

Mouse.
How do scientists decide which animal genome to sequence next?

In the July 16 issue of Nature, genetic researchers announced that they had finished sequencing the genomes of two species of parasitic flatworms that cause the disease known as snail fever. The flatworm is just the latest in an expanding list of sequenced genomes that now includes the human, the fruit fly, the mouse, the cat, the duck-billed platypus, various bacteria, and hundreds of other species. How do scientists decide which genome to sequence next? They follow the money. The National Institutes of Health, which helps fund at least half of the nation's genome-sequencing research, regularly receives project proposals from scientists. In a white paper, researchers explain why they want a particular organism sequenced—why it's useful, what they hope to learn, etc. (See a group of scientists make the case for the rhesus macaque.) An NIH advisory committee then decides which proposals to prioritize by looking at several criteria: the odds that the newly mapped genome will improve human health and biological understanding, cost of sequencing, suitability of the organism for experimentation, and demand in the scientific community for the new sequence data. NIH then allocates funds accordingly. (Check out the list of completed, pending, and future sequencing projects.)

Scientists often target organisms that are already used in the laboratory, since their genomes are likely to be the most useful. Accordingly, the mouse, the fruit fly, the zebra fish, and the roundworm were among the first sequenced genomes. (NIH is still going through all the different types of fruit fly.) Researchers may also choose a particular organism in order to compare its genome with one they already have. Such comparisons help reveal which DNA sequences correlate with which physical characteristics, like eye color or having a head. Other times, scientists will compare genomes within a single species. For example, the researchers behind the 1,000 Genomes Project are comparing 1,000 human genomes and examining the variations among them. The Cancer Sequencing Project, meanwhile, compares human genomes to find the DNA coding associated with particular tumor types.

Advertisement

If you have enough money, you can always fund your own sequencing. But the vast majority of funding comes from government agencies. The U.S. Department of Agriculture, for example, put up funds to sequence the horse genome. Australian researchers with help from the NIH sequenced the kangaroo genome. Chinese scientists at the Beijing Genomics Institute, meanwhile, sequenced the giant-panda genome.

How much does sequencing cost? The original Human Genome Project cost $300 million and took more than a decade. But that project established a template that made every subsequent undertaking quicker. These days, you can get a complete individual human genome sequenced for about $50,000. (That doesn't include the fixed costs of the sequencing machine, lab space, etc.) But that cost is plummeting. One independent company will sequence part of your genome—usually the parts related to particular genetic diseases—for $5,000. And some genetic scientists predict that sequencing an entire genome will soon cost $1,000 and take 20 minutes.

Got a question about today's news? Ask the Explainer.

Explainer thanks Adam Felsenfeld and Larry Thompson of the National Human Genome Research Institute.

Christopher Beam is a writer living in Beijing.

TODAY IN SLATE

Medical Examiner

Here’s Where We Stand With Ebola

Even experienced international disaster responders are shocked at how bad it’s gotten.

Why Are Lighter-Skinned Latinos and Asians More Likely to Vote Republican?

A Woman Who Escaped the Extreme Babymaking Christian Fundamentalism of Quiverfull

The XX Factor
Sept. 22 2014 12:29 PM A Woman Who Escaped the Extreme Babymaking Christian Fundamentalism of Quiverfull

Subprime Loans Are Back

And believe it or not, that’s a good thing.

It Is Very Stupid to Compare Hope Solo to Ray Rice

Building a Better Workplace

In Defense of HR

Startups and small businesses shouldn’t skip over a human resources department.

How Ted Cruz and Scott Brown Misunderstand What It Means to Be an American Citizen

Divestment Is Fine but Mostly Symbolic. There’s a Better Way for Universities to Fight Climate Change.

  News & Politics
Politics
Sept. 22 2014 6:30 PM What Does It Mean to Be an American? Ted Cruz and Scott Brown think it’s about ideology. It’s really about culture.
  Business
Moneybox
Sept. 22 2014 5:38 PM Apple Won't Shut Down Beats Music After All (But Will Probably Rename It)
  Life
Outward
Sept. 22 2014 4:45 PM Why Can’t the Census Count Gay Couples Accurately?
  Double X
The XX Factor
Sept. 22 2014 7:43 PM Emma Watson Threatened With Nude Photo Leak for Speaking Out About Women's Equality
  Slate Plus
Slate Plus
Sept. 22 2014 1:52 PM Tell Us What You Think About Slate Plus Help us improve our new membership program.
  Arts
Brow Beat
Sept. 22 2014 9:17 PM Trent Reznor’s Gone Girl Soundtrack Sounds Like an Eerie, Innovative Success
  Technology
Future Tense
Sept. 22 2014 6:27 PM Should We All Be Learning How to Type in Virtual Reality?
  Health & Science
Medical Examiner
Sept. 22 2014 4:34 PM Here’s Where We Stand With Ebola Even experienced international disaster responders are shocked at how bad it’s gotten.
  Sports
Sports Nut
Sept. 18 2014 11:42 AM Grandmaster Clash One of the most amazing feats in chess history just happened, and no one noticed.