SCIENTISTS who headed teams that independently demonstrated the interruption of coding sequences in eukaryote genes are this year's recipients of the Nobel Prize for Physiology or Medicine. They are Kentucky-born Phillip A. Sharp, PhD, 49, who heads the Biology Department, Massachusetts Institute of Technology (MIT), Cambridge, and Richard J. Roberts, PhD, 50, born in Great Britain but now research director, New England Biolabs, Beverly, Mass.
Both teams reported on the so-called split genes in 1977 while working with adenoviruses. Until then, many assumed that genes had continuous stretches of chromosomal DNA, serving as templates for RNA molecules and directly corresponding to amino acid sequences of the proteins that they specify.
Introns and Exons
But the teams' work confirmed the presence of intervening "nonsense segments" called introns—found in the genes of organisms more complicated than bacteria—that have no role in the normal coding of protein structure. If not properly snipped out