Sharp, Phillip Allen (1944– )

US molecular biologist who was awarded a Nobel Prize for Physiology or Medicine in 1993 with Richard Roberts for their discovery of split genes (genes interrupted by nonsense segments of DNA). Using his technique for measuring nucleic acid fragments on genes, he found that genes consist of regions of DNA (genetic material) separated by regions that do not contain genetic information, called introns.

Sharp developed S1 nuclease mapping, a technique to measure the size of nucleic acid fragments in genes. He then used this technique to determine that genes are split into several regions.

In 1977, he and Roberts independently reported that a single adenovirus messenger RNA molecule corresponded to four distinct regions of DNA, and that different regions of DNA are separated by introns that do not carry genetic information.

Up until that meeting it had generally been thought that genes were continuous stretches of DNA which served as direct templates for messenger RNA (mRNA) molecules, and that these mRNA molecules were themselves templates for protein synthesis. However, before the protein can be translated from the messenger RNA, these introns have to be spliced out. Most eukaryotic genes are now known to have introns and failure to be able to remove an intron is known to cause genetic diseases, for example some forms of thalassaemia.

Sharp was born in Kentucky and educated at Union College and the University of Illinois. He worked at the Cold Spring Harbor laboratories in New York and then at the Massachusetts Institute of Technology in Boston.