21337MGR%MSU@PUCC.PRINCETON.EDU ("Jonathan.Walton") (05/09/91)
Research Opportunity in Molecular Evolution I am looking for a postdoctoral researcher to work on a novel biological system with some interesting evolutionary ramifications. My laboratory studies primarily the biochemical and molecular genetic aspects of plant pathogenic fungi. We are studying genes that control biosynthesis of toxins that are causally related to virulence and pathogenicity. The natural history of these fungi and their toxins suggests that toxicogenesis has evolved in the evolutionarily very recent past, and we are interested in testing the possibility that the toxin genes have moved between fungal species by horizontal gene transfer. Ideally I would like to entice an evolutionary biologist who would be competitive for one of the Sloan Fellowships in molecular evolution. The person should be a recent Ph.D. and preferably changing fields. The applications are due September 6. The filamentous fungus Helminthosporium (aka Cochliobolus) has caused several severe epidemics in the U.S., notably the Southern Corn Leaf blight epidemic of 1970. The susceptible genotype of corn had only been grown for 10 years before a new race of the fungus appeared making a toxin (a polyketide) that is toxic only to that one kind of corn. Toxin production is controlled by a sing le Mendelian gene. (The fungus has nice classical genetics and can be transformed easily. Transformation is homologous so gene disruptions can be done). We have cloned another "toxin" gene from a related fungus. This "gene" is actually a 22 kb cluster and is completely lacking in all other races and species of Helminthosporium. Another three unrelated fungi are known to make closely related compounds (a cyclic tetrapeptide in this case). We would like to test if the TOX DNA moved horizontally from one of these other fungi into Helminthosporium, thereby enhancing its pathogenic fitness. For more details on the system: Walton, JD (1991) In: SA Leong and RM Berka "Molecular Industrial Mycology", M. Dekker, New York, p. 225. Jonathan Walton (21337mgr@msu), (517)353-4885, DOE-Plant Research Laboratory, Michigan State University, E. Lansing, MI 48824 USA.