fruit genome projects ripen on the vine

250 NATURE MEDICINE • VOLUME 9 • NUMBER 3 • MARCH 2003

NEWS

Now that scientists have finished farmingthe human genome, they are turning farafield for new ventures. Several genomeprojects that will begin this year are quiteliterally rooted in the field: grapevines, cit-rus and peach trees, and even the hum-drum broccoli.

The grape is one of the most economi-cally important fruit crops in the world,and yet the biology of grapevines is rela-tively unknown, says Australian researcherMark Thomas, who chairs theInternational Grape Genome Project. Thegroup has recently released a white paperoutlining research goals and is seeking sci-entists to join the project. Sequencing thegrape genome could improve crop yield,fruit and wine quality, and resistance topests and diseases.

Plant genome research is expected to geta boost when the US National PlantGenome Initiative releases its five-yearplan for 2003–2008. The plan calls for de-tailed genetic analysis of “key plantspecies,” which officials have thus far de-clined to name.

Some genome projects that appearready to bear fruit include the peach tree,viewed as the best candidate for deep ge-netic sequencing. The peach, which has a

relatively small genome, could serve as amodel for a wide range of trees, saysMikeal L. Roose of the University ofCalifornia-Riverside. “We don’t have agood model for fruit trees, and the peach isrelated to almost all the important fruitand nut trees,” he says.

Citrus researchers, meanwhile, arejuiced up about a proposal to establish aninternational citrus genome steering com-mittee. Spanish researcher VicenteConejero has offered to host a meeting toprioritize genome projects of interest tocitrus researchers and discuss an open-ac-cess collaborative citrus genome database.

Brassica, a family of plants includingbroccoli and cabbage, is the subject of an-other international project. The plants

may offer insight into polyploidy, one ofthe stranger genetic characteristics ofplants—and one that can make plantgenomes hard to study, says Ian Bancroftof the John Innes Center in Norfolk, UK.

Several of the schemes were announcedin January at the eleventh annual Plant andAnimal Genomes Conference in San Diego.The meeting allows agricultural researchersto be exposed to a wide variety of work inother species, says meeting organizerStephen R. Heller. “You might call it a placewhere a lot of cross-pollinating occurs.”

Some researchers argue that comparingone plant’s sequence to a model genomehastens analysis of specific genes. But be-cause there is significant genetic diversity,others question whether model plants willhave much value.

Many plant genome researchers also sayfinding funding for genome projects canbe difficult. “Agricultural genomics is theRodney Dangerfield field of science,” saysHeller. “It gets no respect.” The USNational Science Foundation is investing$50 to $60 million in plant genome re-search, he says. “But that money repre-sents just a day of work on the humangenome project.”

Damaris Christensen, San Diego

Fruit genome projects ripen on the vine

Direct-to-consumer marketing of genetictesting services in the UK is likely to bestrictly regulated under new proposals bythe government-appointed HumanGenetics Commission (HGC).

The commission wants a statutory regu-lation scheme modeled on one currently inuse for medicines, where products have tobe granted Department of Health clearancebefore they are launched. The departmentwill also specify whether tests can be mar-keted over the counter, under pharmacists’supervision, or only with a doctor’s pre-scription.

The UK does not currently have statu-tory control over suppliers of direct-to-con-sumer genetic testing services, only avoluntary compliance agreement datingback to 1997. HGC began re-examiningthe issue in 2002 when a company calledSciona announced its intention to markettests for lifestyle and dietary issues such asalcohol and vitamin intake—somethingthe existing guidelines did not cover.

Last November, HGC indicated it still fa-vored a non-statutory system of self-regula-tion by suppliers. But at a public meeting

on 5 February 2003, chairman HelenaKennedy said subsequent public consulta-tion had shown that most people wantedgenetic testing to be delivered through theNational Health Service (NHS), at least fortests related to serious diseases. As a result,she said, the commission was now con-vinced it needed statutory controls insteadof a “free-for-all.”

“We have moved away from a libertarianposition,” she said. “We now believe testingwith a serious implication for your healthshould go through a medical practitioner.”

Details of which tests would be desig-nated prescription-only would be left tothe Medicines and Healthcare ProductsRegulatory Agency, said Philip Webb,chairman of the HGC’s working group ondirect genetic testing. Webb expects thatthe prescription-only category wouldapply to “more serious” tests, such as thosefor the Huntington chorea gene. “Others,like paternity testing or genealogy testing,could be available through less regulatedsources,” he said.

Not all HGC members are enthusiasticabout the proposed regulations, however.

Several expressed concerns that limitedNHS budgets and staff shortages would re-move patients’ access to prescription-onlygenetic tests.

“We know that the prescription-onlyclassification is used by the NHS as a way ofrationing, and sometimes entirely to pre-vent access to drugs,” said member JohnBurn, professor of genetics at NewcastleUniversity. “This places huge emphasis onthe amount of resources to be given to test-ing.” Without adequate NHS resources, hesaid, patients would be more likely to turnto cheap Internet sources for their tests.

One of the leading independent pressuregroups in the field, Human Genetics Alert,criticized the commission as “weak” and“failing in its duty to protect the public.”

Demanding a ban on over-the-countermarketing of all genetic tests, the organiza-tion’s director, David King, claimed HGChad “ignored mounting evidence inBritain and the United States of the harmthat can arise from the exploitative market-ing of scientifically unvalidated and uneth-ical tests.”

Peter Mitchell, London

UK to regulate ‘serious’ genetic tests

Kimberly Homer

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