Spring 2014 Asa Gray Seminar Series
February 10, 2014
Thomas R. Horton, Ph.D., Associate Professor, Dept. of Environmental and Forest Biology, SUNY ESF
Title: Ectomycorrhizal Ecology Under Primary Succession on Coastal Sand Dunes: Interactions Involving Pinus contorta, Mycorrhizal Fungi and Deer
Abstract: The species of ectomycorrhizal fungi (EMF) supporting primary successional pine seedlings and mechanisms for their establishment were investigated. When seedlings germinate near mature trees they are colonized by mycelial networks from a diverse group of EMF supported by the trees. However, seedlings germinating in new areas such as those associated with primary succession do not have this benefit. Are seedlings colonized by the same EMF observed on mature trees or a subset of EMF observed on mature trees? If it is a subset, is it a random selection of those associated with the trees or a specific group? To find out, we collected field seedlings growing among trees in forested zones and away from trees in nonforested zones at the Oregon Dunes National Recreation Area near Eugene Oregon. We compare the list of EMF on seedlings collected from the different areas and as fruiting bodies in the surrounding forests. Laboratory bioassays were used to capture EMF species capable of colonizing pine seedlings in soils collected from the area. Seedlings were also grown in bioassays using sterile soil inoculated with deer fecal pellets collected from the area. A diverse group of fungi were found on field seedlings growing in amongst trees. However, field seedlings from nonforested zones and all laboratory bioassay seedlings were dominated by EMF species in just two related genera, Suillus and Rhizopogon. We conclude that Suillus and Rhizopogon spp., the so-called suilloid fungi, are the principle EMF species supporting seedlings on the sand dunes, are dispersed from forested areas across the dunes by deer, and can lay dormant in soils as a resistant spore bank analogous to resistant seed banks.
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March 3, 2014
Rebecca A. Pinder, Ph.D., Adjunct Instructor, Science Department, Columbia-Greene Community College, Hudson, NY
Title: Earthworm Ecology In The Riparian Zone
Abstract: My research established the presence of native and exotic earthworms along forested headwater stream banks in New York State, and focused on four aspects of earthworm ecology in riparian zones: species composition and distributions; community structure of earthworm assemblages; food web interactions; and their influence on nutrient cycling.
Earthworm species abundance at 14 headwater streamside sites in the Catskill State Park and the Helderberg Plateau, were tested for patterns among earthworm species assemblages, including correlations with habitat variables often cited as predictors of earthworm community structure. Over 2250 individuals of 19 species were collected over six sampling periods, including the native species Eisenoides lonnbergi. Habitat variables, primarily associated with soil pH, were correlated with distributions of a few species; but the majority were organized in assemblages with distinct but unexplained regional variation, indicating possible differences in dispersal histories or other unexplained variables.
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March 24, 2014
Ewa Szymanska Mroczek, Ph.D., University of Alabama at Birmingham
Title: Graduate School, Basic Immunology, and Antibody Deficiencies
Abstract: Depressed serum immunoglobulin levels (sIgs) and recurrent sinopulmonary infections mark Common Variable Immune Deficiency (CVID). Many family members of CVID patients also suffer recurrent sinopulmonary infection (RESPI) but have normal sIg. We identified HLAB44 positive identical female twins who suffer sinopulmonary infections and are discordant for CVID and RESPI. Flow cytometry subsets showed equivalent numbers of immature B cells (BC) in both twins, but lower numbers of transitional and mature BC in the CVID twin. Deep sequencing of the immunoglobulin (Ig) repertoires expressed by the transitional and mature BC showed a significant divergence in the utilization of VH1 and VH4 family gene segments, with CVID favoring VH4 and RESPI VH1. RESPI twin used JH6 more frequently, whereas CVID twin used JH3. The amino acid composition of CDR-H3 repertoire was compared with a control; the twin and control tyrosine usage in transitional BC was similar (~15%) but greatly diverged in mature BC (control 15%, RESPI 25%, CVID < 10%). Whole genome sequencing revealed homozygosity for a rare CD21 S639N polymorphism and heterozygosity for CD19 L174V. These findings suggest that in addition to an acquired block in BC development at the transitional stage, the CVID twin produces an Ig repertoire that is markedly depleted of tyrosine. This may explain why the function of the Ig repertoire in CVID is more impaired than what might be expected by sIgs levels.
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April 7, 2014
Mira Krendel, Ph.D., Assistant Professor, Dept. Cell and Developmental Biology, SUNY Upstate Medical University
Title: Lessons From Four-Legged Patients: What Mouse Models Can Tell Us About Human Genetic Diseases
Abstract: Mouse models can be used to test whether the loss of function of a specific gene results in disease. Using a knockout mouse model, we discovered that the loss of a cytoskeletal protein, myosin 1e (myo1e), leads to kidney disease in mice, which led us to predict that mutations in the MYO1E gene in humans may cause familial kidney disorders. As predicted, several families with mutations in MYO1E and associated kidney disease have been identified in clinical genetic studies. Myo1e is a component of cell-cell junctions between epithelial cells in the glomerulus, a portion of the nephron that plays a key role in selective filtration of proteins. Mutations in the human MYO1E gene disrupt domains important for Myo1e functions in cells, leading to defects in protein filtration and subsequent kidney failure. Our lab is investigating the role of myo1e in the assembly and maintenance of the renal filtration barrier and the effects that disease-associated mutations have on myo1e activity.
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April 21, 2014
David L. Moore, Ph.D., Asa Gray Distinguished Emeritus Professor of Biology,
Utica College
Title: Asa Gray, Dean of American Botany
Abstract: Of humble origin, Asa Gray was born on a farm in Sauquoit, New York. He spent his early years in central New York, developing an interest in botany even as he completed preparatory work at Fairfield Academy and then a medical degree at Fairfield Medical School. Through his mentor John Torrey of New York City, Asa Gray began a botanical journey that would first introduce him to the foremost American botanists and, eventually, interaction with the greatest European botanists. Gray’s interest in phytogeography and the evolution of plants would influence Charles Darwin, with whom Gray maintained frequent correspondence, and help shape Darwin’s thoughts on evolution. Gray’s impact on plant exploration, classification and the popularization of botany would make him the most important American botanist of the nineteenth century. Asa Gray was the first individual to occupy Harvard University’s Fisher Professorship of Natural History, the first full-time professorship in North America dedicated to Botany. He also established the Gray Herbarium at Harvard University as one of the preeminent botanical and scientific collections in the world.