Fungal Viruses and Killer Factors — Ustilago maydis Killer Proteins

Abstract

In studies on the genetics and biochemistry of the host—virus interactions, as in many other biological phenomena, the preferred systems are those with a short generation time in which biochemistry and genetics can be studied simultaneously. The fungi, as a relatively simple group of eukaryotic organisms, have played a prominent role in basic research on the genetic expression at the cellular level (Beadle and Tatum, 1941; Beadle, 1946) as a model system that is amenable to both genetic and biochemical analysis. However, in all the research on virus—host interactions the fungi stand out as a unique group in which little reference to viruses was ever made. Numerous extrachro-mosomally inherited phenomena in fungi have been reported, such as unstable somatic segregation (Arlett et al., 1962; Grindle, 1964; Jinks, 1966), senescence (Marcou and Schecroun, 1969), vegetative death (Jinks, 1959), and even plaque formation (Koltin et al., 1973). However, the presence of viruses in the fungi was shown clearly only in the early 1960’s.

The study was supported in part by to the first author the Branch for Basic Research, Isrel Academy of Sciences.