| Citation | Professor Hopwood has done outstanding work on the genetics of actinomycetes. He discovered genetic recombination of Streptomyces and developed original systems of genetic mapping which led him to the demonstration of a circular linkage group. This mapping work was important both in strengthening the generalization that the prokayotes in general have circular chromosomes and in showing a tendency towards symmetry in the map suggestive of evolution by genome doubling. His electron microscope studies (with A. Glauert) showed beyond doubt the prokaryotic affinities of Streptomyces and demonstrated for the first time the existence of membranous "organelles" in continuity with plasma membrane. He has shown that the fertility system of Streptomyces coelicolor involves a sex factor associated with a plasmid. In the course of these studies he has discovered the first clear example of a plasmid-encoded antibiotics synthesis. Hopwood and his group have also extended the genetic analysis to other species of Streptomyces and Nocardia and demonstrated efficient DNA-mediated transformation to Thermoactinomyces. Current studies are directed towards the genetic analysis of development in S. coelicolor. While G. Semonti made some of the basic observations on recombination independently, Hopwood has been the prime mover in most of the advances. He now has an established international reputation as the leading pioneer and authority in what has become a very important aspect of microbial genetics. |