Harvard Researchers Acclaim New British Genetic Discovery

Harvard scientists received as a "delightful surprise" the discovery by British researchers that the same gene can figure in an organism's production of not one, as previously thought, but two proteins.

"It's as good as being able to play squash and take a nap at the same time," David H. Dressler, associate professor of Biochemistry, said yesterday.

While determining the entire 5375 nucleotide sequence which determines the genetic make-up of the virus Phi-X174, the group at the Laboratory of Molecular Biology in Cambridge, England found that the same portions of the sequence could be 'read' in two different ways, each leading to the synthesis of a different protein.

In a chain of twelve nucleotides, for example, each three successive nucleotides determine a protein. The Cambridge group found that the same nucleotide may be part of different triplet patterns beginning with the first in the sequence and the second or third.

Dressler said this phenomenon is similar to being able to read a string of letters such as "I saw a cat" divided differently into "Is aw ac at." In this example, as in most sentences and genetic sequences, the alternative reading is nonsense.

The discovery in connection with the virus is unusual in that alternative readings sometimes do make genetic sense and are possible, Dressler said, about as often as one might expect with language.

One Gene, One Vote?

This possibility of dual readings allows the virus to store its genetic information compactly, and is "what you'd expect in a virus which has a very small amount of DNA," Matthew S. Meselson, Cabot Professor of the Natural Sciences, said yesterday.

Although the discovery did uproot the belief that each gene was involved in the production of only a single protein, it is an infrequent enough phenomenon not to require any fundamental re-evaluation of current research, Meselson said.