Arber , Werner

(1929–) Swiss microbiologist

Arber, who was born in Gränichen, Switzerland, graduated from the Swiss Federal Institute of Technology in 1953 and gained his PhD from the University of Geneva in 1958. He spent a year at the University of Southern California before returning to Geneva where he became professor of molecular genetics in 1965. In 1971 Arber moved to Basel to take the chair of molecular biology.

In the early 1950s Giuseppe Bertani reported a phenomenon he described as ‘host-controlled variation’ in which phage (the viruses that infect bacteria) successfully growing on one host found it difficult to establish themselves on a different bacterium. In 1962, he proposed that bacteria possess highly specific enzymes capable of destroying invading phage by cutting up their DNA. The existence of such ‘restriction enzymes’ as they came to be called was later established by Hamilton Smith.

It turned out that, as Arber had proposed, the enzymes attack the invading DNA at a specific site, always cutting them at exactly the same place. It was this property that endowed restriction enzymes with such interest for if strands of DNA could be so manipulated to be cut at particular known points, it only needed the power to join such strands together in desired combinations for genetic engineering to be a reality. As restriction enzymes were found to leave DNA strands ‘sticky’ and ready to combine with certain other ‘sticky’ strands it was soon apparent to molecular biologists that genetic engineering was at last a practical proposition.

For his work on restriction enzymes Arber shared the 1978 Nobel Prize for physiology or medicine with Smith and Daniel Nathans.