|Spotting the Fakes: 20,000 Human “Pseudogenes”|
By Edward R. Winstead
Posted: January 9, 2004
German researchers have identified about 20,000 human “pseudo” genes—or look-alike genes—in the human genome and say the total number may be much higher.
“We think we’ve only seen the tip of the iceberg,” says Peer Bork of the European Molecular Biology Laboratories in Heidelberg, Germany, who led the study.
Pseudogenes are stretches of DNA that look like genes but do not produce any gene products. Sometimes referred to as “dead” genes, they have accumulated in the human genome over the course of evolution.
Bork’s group undertook the study three years ago with the goal of helping the genome-sequencing community “clean up” the lists of human genes by eliminating pseudogenes that ended up on the lists by mistake. The new findings appear in Genome Research.
In a separate study, scientists from Yale University in New Haven, Connecticut, identified 8,000 pseudogenes, of the type known as “processed” pseudogenes.
The researchers plan to use the information to study the evolution of the human genome, but they point out that some processed pseudogenes are relevant to human health. For instance, at least four pseudogenes resemble cytokeratin 19, a gene that is active in breast and lung tumors.
Thus, scientists studying cytokeratin 19 should be aware of the pseudogenes when conducting experiments involving the gene, notes the Yale team, led by Mark Gerstein. Their findings also appear in Genome Research.
“Pseudogenes have a lot to say about evolution, and they’re worth studying in their own right,” says Gerstein.