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Research - Faye Murrin

My research has focused on two aspects of fungal biology. I am presently working on ectomycorrhizal basidiomycetes, key components of boreal forest ecosystems. Most of my earlier research focused on the cell biology of Entomophaga aulicae, an insect-pathogenic fungus which is an aggressive pathogen of several important forest pests.

Cortinarius mucosus1) Ectomycorrhizal Basidiomycetes in Boreal Forests

Protoplasts of Entomophaga2) Cell Biology of insect pathogenic fungi

1)Ectomycorrhizal Basidiomycetes in Boreal Forests

Overview: Our long-term goal is the quantitative study of ectomycorrhizal fungal communities associated with mature and disturbed Balsam Fir within Terra Nova National Park and the assessment of disturbance on these communities and on forest structure. Increasing environmental stress and the accompanying decrease in biodiversity foreshadows a decline in the stability of ecosystems world wide. In Terra Nova National Park , Balsam Fir stands are being replaced by Black Spruce as a result of natural and anthropogenic activities, decreasing biodiversity within the Boreal Forest. Fungi are critical to ecosystem function in a variety of ways including in their roles as saprotrophs, pathogens and symbionts. Many basidiomycetes act as ectomycorrhizal symbionts of forest trees, forming intimate associations with tree roots, enhancing tree health and affecting forest structure. These ectomycorrhizal fungi (EMF) produce macroscopic fruit bodies in the form of mushrooms.

Because so little is known about the EMF species of TNNP, or of the island of Newfoundland , the first focus of our study is an inventory of ectomycorrhizal mushrooms of mature and disturbed fir stands in the Park. Over a three year period our goal was to produce species descriptions and a regional key to the species of EMF associated with Balsam Fir. The five year's data (2000-2004) from several thousand collections resulted in the identification of approximately 180 species of EMF associated with Balsam Fir and other species in the Park. Most recently, 2005 and 2006 we have used these data as the basis for quantitative studies on disturbance effects.

Reports:

Murrin, F. Quantitative analyses of mycorrhizal basidiomycetes in disturbed areas of TNNP. Parks Canada. May 2006.

Murrin, F. The Tip of the Iceberg: a five year study of mycorrhizal mushrooms in Terra Nova National Park . Parks Canada. 2005.

Murrin, F. Ectomycorrhizal Basidiomycetes of Terra Nova National Park. Years 1-3. Parks Cananda. 2001-3.

Student Thesis:

2005-6 LeCointre, C. Quantitative analysis of ectomycorrhizal basidiomycetes in disturbed areas of Terra Nova National Park.

Presentations:

Murrin, F. & LeCointre, C. Ectomycorrhizal mushroom communities in the boreal forest of the island of Newfoundland : the impact of introduced moose. Mycological Society of Annual Meeting, Baton Rouge, Louisiana , August 2007.

Murrin, F. The Tip of the Iceberg: A five year study of mycorrhizal biodiversity in the boreal forest of coastal Newfoundland. Mycological Society of Annual Meeting, Hilo, Hawaii, July 2005.

Murrin, F. Commercial mushrooms of Newfoundland. Canadian Botanical Association. Montreal, Quebec. 2005. (invited symposium presentation)

Murrin, F. Mushrooms as non-timber forest products in Newfoundland and the Atlantic Region. Third International Workshop on Edible Mushrooms. University of Victoria, British Columbia, August 2003. (invited symposium presentation)

Murrin, F. Commercial mushroom harvesting in the Atlantic Provinces. Canadian Botanical Association. Kalowna, BC. 2003. (invited symposium presentation)

Murrin, F. The epigeous ectomycorrhizal basidiomycete community in balsam fir-dominated, coastal boreal forest, Newfoundland. Mycological Society of Annual Meeting, 2003.

Murrin, F. Ectomycorrhizal basidiomycetes associated with Balsam Fir in Terra Nova National Park, Newfoundland. Mycological Society of Annual Meeting, 2002.

2) Cell Biology of insect pathogenic fungi

Overview: My research in this area centred on the organization and function of the cytoskeleton of insect pathogenic fungi, using the zygomycete, Entomophaga aulicae, as a model system. This fungus undergoes a unique developmental sequence during infection, which can be reproduced in vitro. In the hemolymph of its larval host, it produces a wall-free protoplast which exhibits a complex shape and undulating movements. My early work focused on the nucleus and mitotic microtubules and later on the cytoplasmic cytoskeleton. in particular changes in its organization and regulation during developmental changes from the tip growth characteristic of hyphae to the unique protoplast form.

Research & development: Entomophaga aulicae is an aggressive pathogen of forest pests, including hemlock looper and spruce budworm. Earlier collaborations with Richard Nolan introduced me to the biocontrol applications of research on this organism. After his death, in collaboration with Seabright Corporation and with funding from Forestry Canada, I was able to finish the requirements for a patent that he had in progress, and that patent was granted in his name in 1996. I also was able to extend his work on the mass fermentation production of hyphal bodies of Entomophaga to include another economically important species, E. maimaiga, a pathogen of gypsy moth.

Selected publications, student theses, presentations and workshops

Selected Publications & reports:

Murrin, F. Fungi and Insects. 1996. In THE MYCOTA, Vol.VI Animal & Human Relationships. K. Esser & P. Lemke, eds. Springer-Verlag, Heidelberg, . pp 365-388. Invited Review Chapter.

Murrin, F. The mass fermentation of the gypsy moth pathogen, Entomophaga maimaiga. Prepared for the Canadian Forestry Service, April 1995.

Murrin, F., and R.A. Nolan. 1989. Ultrastructure of conidial germ tube development in vitro by the insect pathogen Entomophaga aulicae. J. Bot. 67: 754-762.

Murrin, F., W. Newcomb, and I.B. Heath. 1988. Ultrastructure and timing of events in the nuclear cycle of the fungus Entomophaga aulicae. J. Cell Sci. 90: 501-516.

Murrin, F., and R.A. Nolan. 1987. Ultrastructure of the infection of spruce budworm by the fungus Entomophaga aulicae. J. Bot. 65: 1694-1706.

Murrin, F., J. Holtby, R.A. Nolan and W.S. Davidson. 1986. The Genome of Entomophaga aulicae (Entomophthorales, Zygomycetes): Base Composition and Size. Experimental Mycology 10: 65-75.

Murrin, F., I.B. Heath and W. Newcomb. 1984. The taxonomic significance of the mitotic spindle and nucleus-associated organelle in Entomophaga aulicae. Protoplasma 120: 84-90.

Student theses:

M.Sc. Graduate Students:

1998 - 2001 Li, Bing. A preliminary report on an integrin-like protein in prototoplasts of the entomopathogenic fungus Entomophaga aulicae

1995 - 1997 Lamb, Mary. Osmotolerance and potassium ion channels in protoplasts of entomophthoralean fungi.

1992 – (1996) Power, D. The actin cytoskeleton of the entomopathogenic fungus, Entomophaga aulicae.

B.Sc. Honors Students:

2004 - Hardy, Thomas W The effect of FM4-64 on the ultrastructure of the insect pathogenic fungus, Entomophaga maimaiga.

2001/2 - Driscoll, J. The microtubule cytoskeleton in protoplasts of the insect pathogenic fungus Entomophaga maimaiga.

1999- Beaurepaire, C. Anti-microtubule drugs inhibit nuclear division (but not nuclear migration) in conidia of the insect pathogenic fungus Entomophaga aulicae.

1998- Pike, Krista Effects of the microtubule inhibitor nocodazole on two stages of an insect pathogenic fungus Entomophaga aulicae.

1998- Borden, Stephanie Effects of the actin inhibitor latrunculin B on two stages of an insect pathogenic fungus Entomophaga aulicae.

1994 Lake , Norbert Attachment and scanning electron microscopy of protoplasts of Entomophaga aulicae.

1992 Taylor , Rodney Microtubules in protoplasts of the fungus, Entomophaga aulicae: a computer-aided three- dimensional reconstruction.

NSERC Undergraduate Awardees:

1999 Kennedy, Robert Osmotolerance and ion channels in fungi.

1995 Hicks, Kelley Ion channels in fungal protoplasts

1994 Hicks, Kelley Freeze substitution of fungal cells

1993 Jenkins, Debbie Freeze substitution of fungal cells

Presentations at Scientific Meetings:

Murrin. F. Integrating cytoskeletal function in entomopathogenic fungi. In “Cell Biology of Fungi” Invited Symposium Presentation. Mycological Society of Annual Meeting, Sault Lake City, Utah , August 2001.

Murrin, F. Nuclear movement in germ tubes and protoplasts of the zygomycete Entomophaga aulicae. Mycological Society of Annual Meeting, Vermont , August 2000.

Li, B & Murrin, F. Integrin in the insect-pathogenic fungus, Entomophaga aulicae. Mycological Society of Annual Meeting, Vermont , August 2000

Borden, S, B. Li, & K. Pike. Cytoskeleton inhibitors MBC, Taxol, and Latrunculin B, differentially affect two infective stages of an insect‑pathogenic fungus. Poster presented at the Canadian Microscopy Society of Canada Meetings, Memorial University , September 1998.

Murrin, F. & N. Lake . Attachment and scanning electron microscopy of protoplasts of the insect pathogen, Entomophaga aulicae. Mycological Society of Annual Meeting, Montreal , August 1997.

Lamb, M., P. Moody-Corbett & F. Murrin. Osmotic tolerance and ion channels in entomophthoralean protoplasts. Mycological Society of Annual Meeting, Indianapolis, Indiana , June 1996.

Murrin F. Freeze substitution of protoplasts and hyphae of the zygomycete, Entomophaga aulicae. Mycological Society of Annual Meeting, San Diego, California , August 1995.

Murrin, F., K. Hicks, M. Lamb & P. Moody Corbett. Osmotic tolerance and potassium ion channels in protoplasts of entomophthoralean fungi. Society of Invertebrate Pathology. Ithaca, New York , July 1995.

Murrin, F. Motility of entomophthoralean protoplasts: mechanism & function. 5th International Mycological Congress. Vancouver , B.C. August 1994.

Jenkins, D. & F. Murrin. Preservation of the fine structure of an insect-pathogenic fungus using freeze substitution techniques. Atlantic Universities Undergraduate Conference. Charlottown, PEI . March 1994.

Murrin, F. The function of the cytoskeleton in protoplasts of the entomopathogen E. aulicae. Mycological Society of Annual Meeting. Athens, . June 1993.

Murrin, F., R. Taylor & D. Power. The function of the cytoskeleton during development in the insect-pathogenic fungus Entomophaga aulicae. Mycological Society of Annual Meeting. Portland, Oregon . August 1992.

Murrin, F. Evolutionary implications of the cytoskeleton of the zygomycete fungus Entomophaga aulicae. International Society of Evolutionary Protistology. Universite de Paris Sud, Orsay, . July 1992.

Power, D., & F. Murrin. The actin cytoskeleton of the insect-pathogenic fungus Entomophaga aulicae. Canadian Society for Plant Physiology Annual Meeting. St. John's , Nfld. July 1992.

Taylor, R. & F. Murrin. The microtubule cytoskeleton of the insect-pathogenic fungus Entomophaga aulicae: Computer-aided reconstructions of serial sections. Canadian Microbiological Society Annual Meeting. St. John's , Nfld. June 1992.



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