Contact Information Denis H. Lynn |
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Areas of Focus
- Molecular/cellular evolution
- Ecology of the microbial loop
- Biology of ciliates
Current and Recent Grad Students
- Chantangsi, Chitchai
- Gentekaki, Eleni
- Noyes, Megan
- Rip, Jason (co-advised by Kevin McCann)
Education
- BSc Guelph 1969
- PhD Toronto 1975
Teaching
- ZOO*2050DE Natural History of Ontario
- ZOO*2070 Invertebrate Zoology II
- ZOO*2080 Invertebrate Zoology II
- ZOO*3000 Comparative Histology
- ZOO*3500 Research in Zoology
- ZOO*6060 Special Topics in Evolution
Research Related Web Sites
Research Interests
My research program is broadly focused on the biology of ciliated protozoa. I am interested in a variety of aspects of their biology, from explaining how they function as unicellular organisms to exploring their role in a variety of ecosystems to describing their adaptive diversity and evolution. Research questions in my lab are generally carried out under the two major topics below, providing flexibility to students to choose a research question of interest to them.
Ecology of ciliated protozoa
Ciliates are the most conspicuous unicellular organisms in a variety of microbial ecosystems. They are found from the poles to the equator, in sea ice and in hot springs, in desert soils and tropical forest litter, and in small temporary ponds to the major oceans. Our research has developed quantitative cytological procedures for sampling the diversity of ciliates in aquatic and terrestrial ecosystems. We have explored the diversity and abundance of ciliates in temperate and tropical marine ecosystems and in temperate and tropical freshwater ecosystems. This research has demonstrated their significant role as links in the flow of energy in these ecosystems. Current research is focusing on factors that control ciliate biodiversity in temperate and tropical soils. Many ciliates feed upon bacterial populations, which are the major mineralizers of organic matter in these ecosystems. We are addressing such questions as how is ciliate biodiversity influenced: 1) by the diversity of these prey bacterial populations; 2) by the complex organic exudates that might vary among plant root system microhabitats; and 3) by variations in temperature, moisture and other physicochemical parameters of the soil matrix?
Biodiversity and phylogeny of ciliated protozoa
Our ecological research depends upon our ability to recognize ciliate diversity. We are able to do this using a variety of techniques and instruments - from cytological stains and light microscopes to gene sequences and computer-constructed phylogenies of molecules. Our research has resulted in a revision of the major lines of evolution in the Phylum Ciliophora. This has relied on data provided by light microscopy, electron microscopy, and gene sequences. We are currently directing our research in molecular phylogenetics along three themes: 1) resolving relationships among ecologically significant groups of ciliates; 2) exploring the origin and relationships of parasitic and other symbiotic species; and 3) discovering genes that may enable identification of species without the need for cytological staining. However, descriptions of cell morphology will continue to be the benchmark requirement for establishing new species. We have described over 30 new species of ciliates from various aquatic ecosystems. There is still much left to learn about the absolute magnitude of the global diversity of ciliates and how loss and change of habitat may influence this diversity.
Selected Research Publications
- Lynn, D.H., Small, E.B.
2002. Phylum Ciliophora. In: An Illustrated Guide to the Protozoa.
Lee, J.J., Bradbury, P.C.,Leedale, G.F. (eds.). Society of Protozoologists,
Lawrence, Kansas. Pp.
371-656
- Acosta, D., Lynn, D.H. 2002.
A preliminary assessment of spatial patterns of soil ciliate diversity
in two subtropical forests in Puerto Rico and its implications for designing
an appropriate sampling approach. Soil Biol. Biochem. 34:125-128.
- Yasindi, A.W., Lynn, D.H.,
Taylor, W.D. 2002. Ciliated protozoa in Lake Nakuru, a shallow alkaline-saline
lake in Kenya: Seasonal variation, estimated production, and role in
the food web. Arch. Hydrobiol. 154:311-325.
- Strueder-Kypke, M., Wright, A.-D.G., Jerome, C.A., Lynn, D.H. 2001. Parallel evolution of histophagy in ciliates of the genus Tetrahymena. BMC Evol. Biol., 5:1. [http://www.biomedcentral.com/1471-2148/1/5]
- Strueder-Kypke, M.C., Wright, A.-D.G., Fokin, S.I., Lynn, D.H. 2000. Phylogenetic relationships of the subclass Peniculia Oligohymenophorea, Ciliophora inferred from small subunit rRNA gene sequences. J. Eukaryot. Microbiol. 47:419-429.
- Lynn, D.H., Munawar, M. 1999. Abundance, biomass, and diversity of planktonic ciliates Ciliophora in Lake Erie. In Munawar, M., Edsall, T., Munawar, I.F. (eds,) State of Lake Erie (SOLE) - Past, Present and Future. Ecovision World Monograph Series, Leiden. Pp. 155-168.
- Dale, T., Lynn, D.H. 1998. Stomatogenesis of the ciliate genus Strombidinopsis with an improved description of S. spiniferum and S. acuminatum. J. Euk. Microbiol. 45:210-217.
- Lynn, D.H., Gilron, G.L. 1993. Strombidiid ciliates from coastal waters near Kingston Harbour, Jamaica Ciliophora, Oligotrichia, Strombidiidae. J. Mar. Biol. Assoc. U.K. 73: 47-65.
- Montagnes, D.J.S., Lynn, D.H. 1993. A quantitative protargol stain (QPS) for ciliates and other protists. In Kemp, P.F., Sherr, B.F., Sherr, E.B., Cole, J.J. (eds.), Aquatic Microbial Ecology. Lewis Publishers, Boca Raton. Ch. 27, pp. 229-240.
- Lynn, D.H., Roff, J.C., Hopcroft, R. 1991. The annual cycle of abundance and biomass of aloricate ciliates in tropical neritic waters off Kingston, Jamaica. Mar. Biol. 110: 437-448.
- Lynn, D.H., Corliss, J.O. 1991. Phylum Ciliophora. in Harrison, F.W., Corliss, J.O. (eds.), Microscopic Anatomy of Invertebrates. Alan R. Liss, New York. Ch. 5, pp. 333-467.
