December 19, 2014
College of Computer, Mathematical, and Natural Sciences

Raymond John St. Leger

Raymond St. Leger

Professor

Contact

Office Phone: 301-405-5402
Fax: 301-314-9290
Office Address: University of Maryland * Entomology Department * Plant Sciences Building * College Park, MD 20742

Teaching

  • ENTM 788, Insect Pathology & Biotechnology
  • CPSP 218L, Biotechnology
  • BSCI 222 (Principles of genetics)

Graduate Program Affiliations

  • Entomology
  • BISI - BISI-Molecular & Cellular Biology (MOCB)

Research Interests

My research is primarily directed towards understanding the biochemistry and molecular biology of entomopathogenic fungi with the aim of using them as a source of innovation for the agricultural industries. Many of my studies have employed the insect pathogenic fungus Metarhizium anisopliae as a model for understanding how fungi respond to changing environments, initiate host invasion, colonize insect tissues, and counter host immune responses. The identification and characterization of fungal toxic products, which are often specific to particular biochemical/organ systems in the insect, has provided a vast resource of genes which we are employing to enhance the pathogenicity of insecticidal fungi and viruses, and to produce insect-resistant plants. The Entomopathogen Genome Resourse (TEGR) at the University of Maryland (http://TEGR.umd.edu) is being used to self-publish our EST projects with M. anisopliae, Conidiobolus coronatus and other fungi. ESTs were used to fabricate M. anisopliae microarrays for genome-wide analysis of the changes in gene expression accompanying infection and other disease processes, and to investigate the genetic circuitry that regulates and executes this program. By comparing genic content and gene expression patterns in ecologically divergent strains of M. anisopliae we are also addressing the origins of intraspecific differences (gene loss/gain, modulation of gene expression) and the mechanisms by which novel pathogens emerge. In terms of Metarhizium biology (specifically) and pathogenic fungi (in general) this approach is providing great insight into: 1) the number, nature and networking of genes that regulate and execute infection processes, 2) factors contolling aggresiveness and the evolution of specificity, and 3) is identifying key factors for precision alterations of pathogen performance. In terms of broader impact genetic variation is proving a powerful tool to study host switching and the molecular basis of adaptation (one of the "Holy Grails" of evolutionary biology) of pathogens.

Recent Publications

  • St. Leger, R.J., Frank, D.C., Roberts, D.W. and Staples, R.C. 1992. Molecular cloning and regulatory analysis of the cuticle-degrading protease structural gene from the entomopathogenic fungus Metarhizium anisopliae. Eur. J. Biochem. 204: 991-1001.
  • Bidochka, M.J. S.R.A. Walsh, M.E. Ramos, R.J. St. Leger, J.C. Silver and D.W. Roberts. 1995. Fate of biological control introductions: Monitoring an Australian fungal pathogen of grasshoppers in North America. Proc. Natl. Acad. Sci. USA 93: 918-921.
  • St. Leger, R.J., Joshi, L., Bidochka, M.J., and Roberts, D.W. 1996. Characterization of chitinases from Metarhizium anisopliae, M. falvoviride and Beauveria bassiana, and ultrastructural localization of chitinase production during invasion of insect cuticle. Appl. Environ. Microbiol. 62: 907-912.
  • St. Leger, R.J., Joshi, L., Bidochka, M.J., and Roberts, D.W. 1996. Construction of an improved mycoinsecticide over-expressing a toxic protease. Proc. Natl. Acad. Sci. USA 93: 6349-6354.
  • St. Leger, R.J., Joshi, L. and Roberts, D.W. 1997. Adaptation of proteases and carbohydrases of saprophytic, phytopathogenic and entomopathogenic fungi to the requirements of their ecological niches. Microbiology 143: 1983-1992.
  • St. Leger, R.J., Joshi, L., and Roberts, D. 1998. Ambient pH is a major determinant in the expression of cuticle-degrading enzymes and hydrophobin by Metarhizium anisopliae. Applied and Environmental Microbiology 64: 709-713.
  • Joshi, L. and St. Leger, R.J. 1999. Cloning, expression and substrate specificity of MeCPA; a Zn-carboxypeptidase that is secreted by an insect pathogenic fungi into infected tissues. J. Biol. Chem. 274: 9803-9811
  • St. Leger, R.J., Screen, S.T., and Nelson, J.O. 1999. The entomopathogenic fungus Metarhizium anisopliae, alters ambient pH, allowing extracellular protease production and activity. Microbiology 145: 2691-2699
  • Bidochka, M.J., St. Leger, R.J., Stuart, A., and Gowanlock, K. 1999. Nuclear rDNA phylogeny in the fungal genus Verticillium and the relationship to insect and plant virulence, extracellular proteases and carbohydrases. Microbiology 145: 955-963
  • St. Leger, R.J., and Screen, S.T. 2000. In vitro. utilization of mucin, lung polymers, plant cell walls and insect cuticle by Aspergillus fumigatus, Metarhizium anisopliae, and Nectria haematococca. Mycol. Research 104: 463-471.
  • Screen, S. E. and St. Leger, R. J. 2000. Cloning, expression and substrate specificity of a fungal chymotrypsin. J. Biol. Chem. 275: 6689-6694.
  • St. Leger, R.J. 2001. Development and testing of genetically improved mycoinsecticides In Enhancing biocontrol agents and handling risks. J. Gressel, T. Butts, G. Harman, A. Pilgeram, R. St. Leger and D. Nuss, editors. Proceedings of a NATO Advanced Research Workshop, June 9-15, 2001. Published (for NATO) by IOS Press, Amsterdam, The Netherlands. Pp, 229-239
  • Screen, S and St. Leger, R.J. (Screen, S. E. and St. Leger, R. J. 2000. Cloning, expression and substrate specificity of a fungal chymotrypsin. J. Biol. Chem. 275: 6689-6694.2000)
  • St. Leger, R.J. and Screen, S. 2001. Prospects for strain improvement of fungal pathogens of insects and weeds. In: Fungal biocontrol agents: Progress, problems and potential. Butt, T.M., Jackson, C., and Morgan, N., eds. CAB International. pp, 219-238
  • Hu, G and St. Leger, R.J. 2002. Field studies using a recombinant mycoinsecticide (Metarhizium anisopliae) reveal that it is rhizosphere competent. Appl. Environ. Microbiol. 68: 6383-6387.
  • Freimoser, F.M., Screen, S., Baga, S., Hu, G. and St. Leger, R.J.(2003) Expressed sequence tag (EST) analysis of two subspecies of Metarhizium anisopliae reveals a plethora of secreted proteins with potential activity in insect hosts. Microbiology 149: 239-247
  • Freimoser, F.M., Screen, S., Hu, G and St. Leger, R.J. (2003) EST analysis of genes expressed by the zygomycete pathogen Conidiobolus coronatus during growth on insect cuticle Microbiology 149: 1893-1900
  • Bagga, S., Screen, S. E. and St. Leger, R.J. 2004. Reconstructing the diversification of subtilisins in the pathogenic fungus Metarhizium anisopliae. Gene.324: 159-169
  • Hu, G. and St. Leger, R.J. 2004 A phylogenomic approach to reconstructing the diversification of serine proteases in fungi. J. Evol. Biol. 17: 1204-1214
  • Wang, C., Hu, G and St. Leger, R.J. 2005. Differential gene expression by Metarhizium anisopliae growing in root exudate and host (Manduca sexta) cuticle or hemolymph reveals mechanisms of physiological adaptation. Fungal Genetics and Biology 42: 704-718
  • Wang, C., Butt, T.M. and St. Leger, R.J. 2005. Colony sectorization of Metarhizium anisopliae is a sign of ageing. Microbiology 151: 3223-3236
  • Freimoser, F. M., Hu, G and St. Leger, R.J. 2005.Variation in gene expression patterns as the insect pathogen Metarhizium anisopliae adapts to different host cuticles or nutrient deprivation in vitro. Microbiol. 151: 361-371
  • Wang, C and St. Leger, R.J. 2005.Developmental and transcriptional responses to host and non host cuticles by the specific locust pathogen Metarhizium anisopliae sf. acridum. Eukaryotic Cell.4: 937-947
  • Wang, C. and St. Leger, R.J. 2006 A collagenous protective coat enables Metarhizium anisopliae to evade insect immune responses. Proc. Natl. Acad. Sci. USA 103: 6647-6652
  • Pal, S., St. Leger, R.J. and Wu, L.P. 2007. Fungal Peptide Destruxin A Plays a Specific Role in Suppressing the Innate Immune Response in Drosophila melanogaster J. Biol. Chem. 282: 8969 - 8977
  • Wang, C. and St. Leger, R.J. 2007 Metarhizium anisopliae perilipin homolog MPL1 regulates lipid metabolism, appressorial turgor pressure and virulence. J. Biol. Chem. 282: 21110-21115
  • Wang, C. and St. Leger, R.J. 2007.The MAD1 adhesin of Metarhizium anisopliae links adhesion with blastospore production and virulence to insects: the MAD2 adhesin enables attachment to plants. Eukaryotic Cell 6: 808-816.
  • Wang, C. and St. Leger, R.J. 2007. A scorpion neurotoxin increases the potency of a fungal insecticide. Nature Biotech.  25: 1455-1456
  • Wang, C and St. Leger, R.J., 2008 MOS1 Osmosensor of Metarhizium anisopliae is required for adaptation to insect host hemolymph. Eukaryotic Cell 7:  doi:10.1128/EC.00310-07
  • Pava-Ripoll, M., Posada, FJ., Momen, B., Wang, C and St. Leger, RJ. 2008. Increased pathogenicity against coffee berry borer, Hypothenemus hampei (Coleoptera: Curculionidae) by Metarhizium anisopliae expressing the scorpion toxin (AaIT) gene. J. Invertebre. Pathol. 99: 220-226
  • Li L., Pischetsrieder M., St. Leger R. J., Wang C. S. 2008. Associated links among mtDNA glycation, oxidative stress and colony sectorization in Metarhizium anisopliae. Fungal Genetics and Biology, 45: 1300-1306.
  • Fang, W., Pava-Ripoll, M., Wang, S. & St. Leger, R.J. 2009 Protein kinase A regulates production of virulence determinants by the entomopathogenic fungus, Metarhizium anisopliae. Fungal Genetics and Biology 46: 277-285
  • Wang, S., Leclerque A, Pava-Ripoll, M., Fang W, & St. Leger R.J. 2009. Comparative genomics using microarrays reveals divergence and loss of virulence associated genes in host specific strains of the insect pathogen Metarhizium anisopliae. Eukaryotic Cell doi:10.1128/EC.00058-09
  • Sibao Wang, Andreas Leclerque, Monica Pava-Ripoll, and St. Leger 2009.  Comparative Genomics Using Microarrays reveals divergence and loss of virulence associated Genes in Host-Specific Strains of the Insect Pathogen Metarhizium anisopliae Eukaryotic Cell 8 888-898
  • Fang, W and St. Leger, R.J. 2010. RNA binding proteins mediate the ability of a fungus to adapt to the cold. Environ. Microbiol. 12 810-820. [Abstract]
  • Fang, W and St. Leger, R.J., 2010 Mrt, a gene unique to fungi, encodes an oligosaccharide transporter and facilitates rhizosphere competency in Metarhizium robertsii Plant Physiol. 154: 1549-1557 [Article]
  • Fang W, Fernandes EK, Roberts DW, Bidochka MJ, St Leger RJ. 2010 A laccase exclusively expressed by Metarhizium anisopliae during isotropic growth is involved in pigmentation, tolerance to abiotic stresses and virulence. Fungal Genet Biol; 47:602-7 [Article]
  • Pava-Ripoll, M., Angelini, C, Fang W., Wang, S, Posada F, St. Leger, R. 2011 The rhizosphere competent entomopathogen Metarhizium anisopliae expresses a specific subset of genes in plant root exudates. Microbiology 157: 47-55 [Article]
  • Gao Q, Jin K, Ying S-H, Zhang Y, Xiao G, et al. (2011) Genome Sequencing and Comparative Transcriptomics of the Model Entomopathogenic Fungi Metarhizium anisopliae and M. acridum. PLoS Genet 7(1): e1001264. doi:10.1371/journal.pgen.1001264 [Article]
  • Fang W, Vega-Rodriguez, J., Ghosh, A.K., Jacobs-Lorena, M., Khang, A and St. Leger, R.J., 2011. Development of transgenic fungi that kill human malaria parasites in mosquitoes Science 331: 1074-1077. [Article]

Awards

  • University of Maryland Distinguished Scholar-Teacher Award, 2009-2010
  • Founder's Lecturer Award, Society of Invertebrate Pathology, 2008
  • College of Life Sciences Faculty Research Award, 2002

Education

  • Ph.D. (1985) and Post-doc (1987) Crop Protection, University of Bath, Avon, U.K.
  • M.Sc. 1980. Entomology, University of London, London,U.K.
  • B.Sc. (Honors.). 1978. Biology, Exeter University, U.K.