Because the specific metabolite produced is unknown, these segments are known as "orphan gene clusters."
It's likely that some orphan gene clusters produce enzymes that could make new antibiotics.
"Orphan gene clusters represent the potential to discover new antibiotics, drugs, and chemicals," says Joyce Loper, a plant pathologist at ARS's Horticultural Crops Research Laboratory (HCRL) in Corvallis, Oregon.
Working with scientists at Scripps Institution of Oceanography at the University of California-San Diego; Oregon State University; and Northland College, in Ashland, Wisconsin, Loper investigated a new method for determining the products of orphan gene clusters.
To do this, the scientists label the chemical building blocks with isotopes and then place the labeled molecules in a culture of the Pseudomonas bacterium that has the orphan gene cluster.
A joint project conducted by Loper and Harry Gross, at the University of Bonn, Germany, demonstrated that a second Pseudomonas orphan gene cluster codes for biosynthesis of compounds related to rhizoxin--an antibiotic and potential antitumor substance.
During early regenerative growth, genes called orphan genes are active, Anoop Kumar of University College London and colleagues report October 26 in Nature Communications.
"It becomes tempting to think that amniotes are hiding a latent capacity to perform complex regeneration, and the correlation with a potential molecular mechanism, orphan genes, points to a good place to start."