He adds, "This study should be a massive springboard for using comparative genomics, and it proves without a doubt the value of sequencing the genomes of a wide variety of species."

The Washington University researchers, led by Susan Dutcher, Ph.D., a professor of genetics, study cilia in an alga called Chlamydomonas. The alga provides easier access than other organisms to examine cilia and related structures called flagella, which also help with cells' own movement.

To find new genes and proteins involved in cilia, Dutcher and her team compared all the proteins predicted by the alga's and human's genomes, and then compared those matches to a weed -- the laboratory plant Arabidopsis. The alga and humans both have cilia, but the weed doesn't, so the researchers could eliminate genes and proteins that aren't involved in cilia, says Dutcher.

The alga and humans shared 4,348 "fairly good" matches. Subtracting those also found in the weed cut the number of likely cilia-related proteins and genes to just 688.

To see if these data might help the hunt for disease genes, Dutcher contacted Katsanis. In 1999, a Canadian team of researchers had determined that BBS5 was in a particular region of chromosome 2. In 2003 and 2004, Katsanis, the Canadians and their colleagues presented evidence that faulty cilia and related structures were likely to be the direct cause of problems seen in people with BBS.

Including BBS5, seven BBS genes now have been isolated and "cloned," and another is known to be on chromosome 3. Katsanis fully expects that many more genes are involved in the syndrome.

"The list of cilia-related genes is likely to be invaluable in identifying additional BBS genes, and it likely includes genes already tied to other diseases and conditions whose traits overlap BBS," says Katsanis.

The cellular problems behind BBS, a rare condition, may also be in
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Contact: Joanna Downer
jdowner1@jhmi.edu
410-614-5105
Johns Hopkins Medical Institutions
13-May-2004