|
For the past several years the Department
of Biological Sciences
at BGSU has put together
a Speakers Bureau. This
Bureau lists faculty members
and the topics they can
present for seminars at
local institutions. Please
browse the list below.
If you are interested in
including any of these
topics in your seminar
program, feel free
to contact the
presenters.
Abstracts for 2008-2009 Faculty Seminars
Verner P. Bingman, Ph.D. (email: vbingma@bgsu.edu;
phone: 419-372-2301)
ADMIRING BIRD BRAINS: THE AVIAN HIPPOCAMPUS
AND THE EXTRAORDINARY MEMORY
AND NAVIGATIONAL ABILITIES OF BIRDS
Brain organization and its relationship to behavior
in any extant group of animals is a reflection of a long evolutionary
history of adaptive change. Birds are the animal world’s supreme
navigators, and aspects of their navigational and spatial memory
ability are dependent on the integrity of the hippocampal formation
of the brain. It follows, therefore, that the hippocampal organization
of birds would be characterized by features adapted to their seemingly
exceptional spatial navigational and memory capacities. Drawing
on data from homing pigeons and other bird species, I will explore
the often remarkable memory and navigational abilities of birds,
and relate those abilities to the organization of the avian hippocampus.
One important property of the avian hippocampus is that, like
in humans, it appears to be functionally lateralized. For example,
in freely moving homing pigeons, the spatial response properties
of left hippocampal neurons differ from the response properties
of right hippocampal neurons. Left and right hippocampal lesions can also have dramatically different effects on
a variety of field and laboratory spatial behavioral challenges.
The observed hippocampal lateralization is likely one adaptive
property of avian hippocampal organization that contributes to
the extraordinary spatial behavior of birds.
Juan L. Bouzat, Ph.D. (email: jbouzat@bgsu.edu;
phone: 419-372-9240)
GENETICS, DEMOGRAPHY, AND THE CONSERVATION STATUS
OF THE GREATER PRAIRIE CHICKEN
The extend to which a species has declined within
its historical range is commonly used as an important criterion
in categorizing the conservation status of wild populations. The
greater prairie chicken has been extirpted from much of the area
it once inhabited. However, within a large part of this area the
species is not considered to be native, warranting no recovery
effort of special protection. Provenance data and genetic information
from museum collections provided insights into the historical
distribution of the Greater Prairie Chicken. Our results suggest
that the current status of the Greater Prairie Chicken should
be re-evaluated within all areas where this species is now considered
non-native. This study demonstrates the value of museum collections
as stores of both ecological and genetic information fundamental
for the conservation of natural populations.
PURGING DURING HISTORICAL
INBREEDING CAN LIMIT
THE THREAT THAT INBREEDING POSES TO POPULATION VIABILITY
An important issue in conservation biology is
the extent to which inbreeding depression can be reduced by natural
selection. If deleterious recessive alleles causing inbreeding
depression can be purged by natural selection, outbred populations
with a history of inbreeding are expected to be less susceptible
to inbreeding depression. Using experimental populations of Drosophila
melanogaster, we show that the magnitude of inbreeding depression
may be reduced by 66% in populations that had a history of inbreeding,
and by 40% in populations with high levels of ancestral inbreeding.
These results suggest that purging can limit the threat that inbreeding
depression poses to population viability and persistence.
George S. Bullerjahn, Ph.D. (email: bullerj@bgsu.edu; phone: 419-372-8527)
STRESS RESPONSES IN BACTERIA
I am currently studying cyanobacteria as models
for how bacteria and phototrophs adapt to changes in environmental
conditions. We have identified several mechanisms that occur during
adaptation to changes in light intensity, and we are also examining
changes in gene expression resulting from nutrient (C, N, S, P)
limitation. This project has identified gene products inducible
during the transition to the stationary phase of growth. Such
work may help define universal rules in the adaptation of bacteria
to changing and extreme environments. Lastly, promoter-gene fusions
employing environmentally-responsive promoters are being developed
as environmental sensors for nutrient bioavailability.
BIOCHEMISTRY OF PHOTOSYNTHETIC
ELECTRON TRANSPORT COMPLEXES
Another project examines the protein/protein
interactions required for productive electron transport to photosystem
I in photosynthesis. This work will help explain the reversible
nature of redox catalyst (plastocyanin/cytochrome c) docking during
biological electron transport reactions.
Michael E. Geusz, Ph.D. (email: mgeusz@bgsu.edu;
phone: 419-372-2433)
THE MAMMALIAN CIRCADIAN TIMING SYSTEM AND THE
ROLE OF DAILY RHYTHMS IN HEALTH AND DISEASE
The tissues of mammals show daily rhythms in
gene expression and protein synthesis. Circadian clock cells in
these tissues are part of a circadian system regulating rhythms
in physiology and behavior that are coordinated with 24-hour cycles
of the environment. The rhythms of the organs and their timing
relationships with each other affect the progression of diseases
and the ability of the brain to function optimally. The circadian
system is disrupted by work schedules, sleep loss, poor health,
and stress acting though both neural and hormonal pathways. To
understand how the circadian system becomes desynchronized, we
are examining molecular changes in response to signaling between
the nervous system and the circadian clocks in mouse pancreas,
cornea, skeletal muscle, and other tissues. In addition, we are
interested in how tumor cell growth is altered by the circadian
system. By characterizing these coupling interactions at the cellular
level, we expect to better understand how the circadian system
of the whole animal is organized and how it can be corrected. The laboratory relies
on molecular imaging of gene expression in cells and tissues of
transgenic mice, histology, pharmacology, neural recording, and
behavioral monitoring of circadian behavior.
Carol A. Heckman, Ph.D. (email: heckman@bgsu.edu;
phone: 419-372-8218)
CANCER AND CELL MOTILITY
Cells undergo a choreographed sequence of cell
shape changes after being treated with a tumor promoter, which
presumably activates protein kinase C. Protein kinase C modulates
aspects of cell differentiation and, in the nervous system, memory.
Because numerous isoforms of this enzyme are present in eukaryotic
cells, it has been difficult to draw a one-to-one correspondence
between each isoform and its function. Since early changes in
shape reflect ruffling activation and the disappearance of filopodia,
small GTPases of the Rho family are implicated in the shape changes.
Two such proteins, rac and cdc42, regulate ruffling and filopodia,
respectively. The investigators seek to determine the role of
protein kinase C isoforms in regulation of these GTPases. The
Rho-family GTPases also have a function in regulating vesicle
trafficking. The research will determine how the morphological
features are related to vesicle trafficking defects of cancer
cells. It will also confirm or deny that different GTPase functions are regulated by individual members of the PKC family.
Robert Huber, Ph.D. (email: lobsterman@caspar.bgsu.edu;
phone: 419-372-0341)
DYNAMIC INTERACTIONS OF BEHAVIOR AND AMINE NEUROCHEMISTRY
DURING ACQUISITION AND
MAINTENANCE OF SOCIAL RANK IN CRAYFISH
Fighting in crayfish is characterized by an
apparent lack of diplomatic skills. Aggressive behavior is stereotyped
and can be described as a sequence of decisions taken by each
individual, e.g., who initiates a fight, whether attack is followed
by retaliation, how quickly fights escalate, and whether or when
an animal chooses to withdraw. The existence of a highly structured
behavioral system in animals with relatively "simple" nervous systems enables us to explore the neurobiological basis of fighting
motivation at levels, which are difficult to achieve in other
systems.
Using this model system, we study the importance of brain chemicals in aggression.
We have shown that the infusion of minute amounts of this substance reverses
the natural dominance relationship -- larger animals no longer prevail. Interdisciplinary
approaches are required to dissect out the processes underlying such decision-making.
Using a combined behavioral, pharmacological, and molecular approach, we are
now exploring the precise roles played by the amine, the dynamic processes
which create and maintain social hierarchies, the signals underlying dominance,
and the particular neuronal centers responsible.
Roudabeh J. Jamasbi, Ph.D. (email: rjamasb@bgsu.edu;
phone: 419-372-8724)
CHARACTERIZATION OF TUMOR-ASSOCIATED ANTIGENS
AND
RECEPTORS BY SPECIFIC MONOCLONAL
ANTIBODIES
Cell transformation and malignancy are often
associated with the expression of tumor-associated antigens (TAA)
that may serve as tumor markers. Tumor-associated antigens are
rarely found to be tumor-specific. However, the expression of
TAAs is often enhanced so that antibodies, particularly monoclonal
antibodies (MAbs), produced against them can differentiate the
tumor cells from the normal tissues. These MAbs are potentially
useful in both cancer immuno-diagnosis and immunotherapy.
Currently, my laboratory is engaged in the production and characterization
of monoclonal antibodies against esophageal carcinomas of both human and experimental
animals. One of the monoclonal antibodies produced recently reacts with an
integrin molecule, which is over-expressed in carcinoma lines. The other monoclonal
antibodies react specifically with glycolipid and/or glycoprotein ( integrin)
molecules associated with cancerous cells. The diagnostic and/or therapeutic
values of these monoclonal antibodies are under investigation. The effect of
curcumin on cancer cell proliferation is also in progress.
The differential expression of several receptors (Cox1, Cox2, Cyclin D1, Cadherin,
and -caterin) in cancerous and non-cancerous cell lines are also being investigated.
In addition, my laboratory is involved in production of monoclonal antibody
to clinically significant microorganisms for the purpose of rapid diagnosis
and epidemiological studies. The mechanisms of pathogenicity of these organisms
are also being investigated.
Ray A. Larsen, Ph.D. (email: larsera@bgsu.edu;
phone (419) 372-9559)
ENERGY TRANSDUCTION IN GRAM-NEGATIVE BACTERIA
The outer membrane of Gram-negative bacteria
is a diffusion barrier that hinders the passage of potential toxins
soluble in typical membranes, while allowing entry of small hydrophilic
nutrients by passive diffusion through aqueous channels formed
by porin proteins. Although it is thermodynamically unlikely that
the integrity of a structure as complex as the outer membrane
can be maintained without energy, it is not energetically self-sufficient;
porin channels preclude the establishment of significant ion gradients,
while the phosphorylated molecules favored as energy currency
do not frequent the adjacent periplasmic space. Thus, any energy-dependent
process at the outer membrane must rely upon imports. The paradigm
for energy delivery to the outer membrane is the TonB system.
This set of proteins couple cytoplasmic membrane-derived energy
to drive the active transport of ferric siderophores and cobalamin
across the outer membrane. While the TonB system itself does not
directly contribute to outer membrane integrity, it shares characteristics with a set of proteins that clearly
does – the Tol system.
The focus of our ongoing research program is two-fold: First, we are using
a biochemical and genetic approach to exploit similarities between the TonB
and the Tol systems to dissect the mechanism by which these systems harvest
the potential energy of the cytoplasmic membrane electrochemical gradient.
Second, we are developing a genetic approach to identify the as yet uncharacterized
proteins that the Tol system energizes to support outer membrane integrity.
Rex L. Lowe, Ph.D. (email:
lowe@bgsu.edu; phone: 419-372-8562)
HOW MANY SPECIES DOES AN ECOSYSTEM SUPPORT?
THE ALL TAXA BIODIVERSITY
INVENTORY OF THE GREAT SMOKY MOUNTAINS NATIONAL PARK.
For the past 11 years there has been a large
international effort to discover every species of life in the
Great Smoky Mountains National Park. This study has been compared
to the ecosystem equivalent of the human genome project. Instead
of mapping every gene in one species we are mapping every species
in one ecosystem. Many surprising discoveries and many species
new to science have been discovered thus far.
FRESHWATER ALGAL BIODIVERSITY ON PACIFIC ISLANDS:
EXPLODING
THE MYTH OF COSMOPOLITAN
DISTRIBUTION.
For many years scientists believed that for
microbial life “everything is everywhere and the habitat selects
what survives." Resent studies in Hawaii, New Zealand, New Caledonia, Vanuatu and elsewhere
that there are an astounding number of endemic species restricted
to specific habitats on specific islands. These discoveries and
the reasons behind them are explored.
R. Michael McKay, Ph.D. (email: rmmckay@bgsu.edu; phone: 419-372-6873)
ASSESSING NUTRIENT BIOAVAILABILITY USING CYANOBACTERIAL
BIOREPORTERS
For decades, our ideas on nutrient availability
in aquatic ecosystems have been informed largely by chemical measurement
of dissolved elements. While this provides a reasonable proxy,
it tells us little about the bioavailability of a given nutrient.
Distinguishing between biologically available, and refractory
forms of a nutrient has been cited as a particular challenge by
the oceanographic community.
The availability of key
nutrients could be better understood if a biological system were
to be used to estimate nutrient supply. Promising in this regard
is the use of genetically-altered organisms as biological reporter
systems to assess the bioavailability of a chemical compound.
The development and use of freshwater cyanobacterial bioreporters
by our group to assess the availability of iron, phosphorus and
nitrogen has been met with interest by aquatic scientists due
to the ability of these tools to offer insight into the availability
of an element from the perspective of an important member of the
endemic phytoplankton community.
Future work in the lab
continues our development and characterization of luminescent
cyanobacterial bioreporters to offer a rapid assessment of nutrient
bioavailability from marine waters. Our recent success in developing
a luminescent whole-cell cyanobacterial bioreporter for measuring
Fe availability in diverse marine environments has provided important
proof of concept. We are now ready to expand the use of bioreporters
to the ocean milieu.
Lee A. Meserve, Ph.D. (email:
lmeserv@bgsu.edu; phone: 419-372-8361)
INFLUENCE OF ENDOCRINE DISRUPTORS ON THYROID
STATUS, DEVELOPMENT, AND
NEUROENDOCRINE CONTROL
MECHANISMS
The alteration of thyroid status during mammalian
development profoundly modifies the rate, and the ultimate completion,
of development of a number of control mechanisms characterized
by the interface of nervous and endocrine systems. For example,
researchers in our lab have demonstrated that depressed thyroid
status delays the development of the hypothalamus-pituitary-adrenal
(HPA) axis response to stress. Appropriate maturation of this
neuroendocrine axis and maintenance of its function are important
to enable an animal to respond physiologically to environmental
challenge. Our current work involves effects in their offspring
of ingestion by pregnant animals of the environmental pollutant
polychlorinated biphenyl (PCB), which also induces hypothyroidism,
and alters HPA axis development as well. Additionally, in young
rats (15 days old) relatively large amounts of dietary PCB (e.g.,
250 ppm) depress the activity of the enzyme choline acetyltransferase
(ChAT), important in the synthesis of the neurotransmitter acetylcholine, in the brain limbic areas: hippocampus and basal forebrain.
While the activity of this enzyme returns to normal by 20 days
of age, deficits in maze learning persist in these animals into
adulthood. On the other hand, smaller amounts of PCB (e.g., 12.5
ppm) have less impact on thyroid status, but more long-lasting
behavioral effects than do large amounts. Current studies are
attempting to tease apart the proportion of PCB effect that is
mediated through thyroid disruption, and the portion that is the
result of other physiological alteration. This is being done through
the use of individual PCB molecular species (congeners), and through
mixtures of small numbers of congeners.
Helen Michaels, Ph.D. (email: hmichae@bgsu.edu;
phone: 419-372-2644)
REPRODUCTIVE ECOLOGY AND CONSERVATION GENETICS
OF PERENNIAL LUPINE
Plants in small and sparse populations often
have low reproductive success, often due to fragmentation of populations
by human activities. We are examining the process of population
decline in Perennial Lupine, a plant species which not only suffers
from habitat loss and fragmentation, but also is an important
indicator species for the imperiled Oak Openings savanna community
of the Great Lakes ecosystem and the only host plant for three
Endangered butterfly species. Studies currently include: 1) the
reproductive biology and mating system 2) the effects of environmental
factors on seedling establishment and 3) the effects of population
size on reproductive success, pollinator services, loss of genetic
diversity, and inbreeding depression.
MOLECULAR EVOLUTION AND ECOLOGY OF ANTENNARIA
Evolutionary relationships within complexes
of asexual polyploid plants are often difficult to resolve with
traditional taxonomic approaches because of extensive overlap
in morphological and ecological characteristics as a result of
hybridization, polyploidy and asexuality. In addition, previously
documented differences in ecological characteristics of sexual
and asexual plants, which might be attributed to the adaptive
advantages of the breeding system, could alternatively be ascribed
to differences in evolutionary history. Phylogenetic relationships
within two agamic polyploid complexes of the Eastern U.S., Antennaria
Parlinii and A. howelli (Asteraceae: Inuleae), were examined using
analysis of chloroplast and nuclear ribosomal DNA restriction
site mutations in order to elucidate the origins of these plants
and to understand the evolution of differences in correlated ecological
charactersitics.
EVOLUTION OF NATIVE HAWAIIAN GERANIUMS
The geraniums endemic to the Hawaiian Islands
have a number of unusual morphological adaptations that are distinc-tive
within genus Geranium. This morphological uniqueness has obscured
both the evolutionary origin of this group and the pattern of
speciation of this small adaptive radiation. Molecular similarities
and differences in chloroplast and nuclear genes are being used
to detrmine the continental source and pattern of relationships
for these unusual plants.
Jeffrey G. Miner, Ph.D. (email: jminer@bgsu.edu;
phone: 419-372-8330)
INVADING SPECIES EFFECTS IN THE GREAT LAKES:
DREISSENID MUSSEL AND ROUND
GOBY EFFECTS ON MACROINVERTEBRATES AND SMALLMOUTH BASS
Invading dreissenid mussels have altered the
Great Lakes community by shifting resources from the pelagic to
the benthos, by clearing the water column increasing light penetration
to the benthos, and increasing habitat structure. Invading round
gobies have increased to the point that there are an estimated
10 billion in the western basin of Lake Erie. As the most productive
region of the Great Lakes, understanding the mechanisms of community
responses to these invasions are essential to predicting and managing
the resource. I present a series of experiments my students, collaborators
and I have conducted to quantify the benthic community responses
to these species invasions and experiments in which we identify
the life stage effects of round gobies on juvenile smallmouth
bass, potentially affecting population dynamics.
OTOLITH MICROCHEMISTRY FINGERPRINTING: FISH
BALANCING ORGAN PROVIDES
INSIGHTS INTO BASIC FISH
POPULATION BIOLOGY
In large aquatic systems like Lake Erie, it
is difficult to monitor important fishery resources. Using laser
ablation, inductively coupled mass spectroscopy (LA-ICPMS) on
fish otoliths (calcium carbonate structures in balancing organs)
we are able to track subpopulations of important sport fishes
to their natal spawning sites (addressing philopatry), distribution
seasonally throughout Lake Erie (migration tracking), and potentially
address important management questions about relative subpopulation
size. I present the conceptual framework for this research with
questions that need to be addressed, explain a series of experiments
we have conducted to determine the extent of philopatry in white
bass and subpopulation identification in western Lake Erie, and
finally address a new project to identify and track the steelhead
trout stocks in Lake Erie using otolith microchemistry.
Paul A. Moore, Ph.D. (email:
pmoore@bgsu.edu; phone: 419-372-8556)
ODOR TRAILS, BEHAVIOR, AND NEURONS: A MULTIDISCIPLINARY
APPROACH TO STUDYING CHEMICAL
ORIENTATION
All organisms must forage, avoid predation,
and reproduce. In a number of organisms, these decisions are guided
by sensory information gathered through smell and taste. By studying
a variety of different organisms (such as lobsters, blue crabs,
copepods, crayfish, catfish and starfish) that live at different
spatial and temporal, we have begun to find general patterns on
how organisms use sensory information in chemical signals to make
decisions on how to locate odor sources in natural habitats.
THE DETERMINANTS OF DOMINANCE
Many organisms exhibit varying degrees of social
behavior in laboratory or natural settings. By using the crayfish
as a model system, w have investigated the external and internal
factors that lead to the structure and organization of social
hierarchies. In crayfish systems, chemical signals play an important
role in providing information on the identity of individuals,
their past history, reproductive state and social status. These
signals have the potential to alter or control subsequent social
behavior exhibited by other individuals. This talk will cover
the role that sensory signals play in structuring social dynamics
in this system.
DARWIN MEETS NEWTON: DESIGN CONSTRAINTS ON SMELLY
APPENDAGES
The laws of physics are like the rules to the
game of life. Organisms participate in this game and are constrained
by these physical rules. By understanding the interplay between
physics and evolution, we can gain insight into the adaptation
of structures and behaviors. This talk outlines how physics and
evolution have interacted to help design the "noses" of different organisms.
Daniel M. Pavuk (email: dmpavuk@bgsu.edu; phone:
419-372-8082)
EFFECTS OF NONCROP HABITATS ON ABUNDANCE AND
DIVERSITY OF PREDATORY
ARTHROPODS AND PARASITOIDS IN AGROECOSYSTEMS
The control of pest arthropods in row crop agroecosystems
has been, and continues to be, a serious problem for corn and
soybean producers in the Midwestern region of the united States.
Pest arthropods of corn and soybean have a major negative impact
on the income and the sustainability of farms throughout the Midwest,
as well as in other parts of the United States. It is highly desirable
and imperative to find control strategies of arthropod pests that
rely more on biological and cultural controls and less on synthetic
pesticides, which tend to have undesirable off-target effects
and contribute to the pollution of the soil and water. In addition,
the problem of pesticide resistance and the cost of pesticides
for producers make strict reliance on these chemicals unsustainable
over the long term. The objective of research in my laboratory
is to intensively investigate noncrop habitats adjacent to crop
fields as sources and refuges of predaceous arthropods and parasitoids,
especially those that feed on pest arthropods of corn and soybean in the North Central Region. Numerous previous
studies of various crops and cropping systems has indicated that
noncrop habitats, such as deciduous woodlots, fencerows, hedgerows,
old fields, grassy strips, and other types of field margin habitats
have genuine potential as beneficial habitats for a wide spectrum
of natural enemies of crop pests., Beneficial as well as pest
arthropods are sampled in edges and centers of corn and soybean
fields using several different sampling methods.
I expect that our research into the positive impact of noncrop habitats on
management of pest arthropods will provide some valuable insights and information
about the utilization of these habitats in the biological control of key arthropod
pests. This research program will significantly increase our awareness and
knowledge of the beneficial aspects of noncrop habitats in the agricultural
landscape. Additionally, the information gained from this research project
could contribute to the enhancement of farm economics and quality of life for
rural communities in the North Central Region. By emphasizing the biological
control of pest arthropods of corn and soybean, this project should further
our understanding and use of biological control as an alternative to conventional
chemical control of pest arthropods in row crop agro-ecosystems.
C. Lee Rockett, Ph.D. (email:
clrocke@bgsu.edu; phone: 419-372-2834)
BACTERIA AS OVIPOSITIONAL ATTRACTANTS FOR AEDES AEGYPTI (DIPTERA:
CULICIDAE)
The effectiveness of selected bacterial species
as ovipositional attractants for Aedes aegyptiI,, Culex pipiens,
and other mosquitoes is being examined. Selected bacterial washes
are utilized as ovipositional substrates and subsequent egg counts
determine the degree of ovipositional attractiveness. Among others,
Bacillus cereus and Pseudomonas aeruginosa have been noted as
being effective attractants. A. aegypti and other mosquitoes appear
to display discriminatory behavior in selecting individual bacterial
species for oviposition.
Work in the laboratory and field is being conducted to fully delineate the
role of bacteria as ovipositional attractants for gravid mosquitoes. It is
tempting to speculate that, in the future, bacteria might be utilized as ovipositional "lures" for
mosquito control purposes.
Scott O. Rogers, Ph.D. (email: srogers@bgsu.edu;
phone: 419-372-2333)
LIFE IN ANCIENT ICE: GENOME RECYCLING AND ITS
IMPLICATIONS
We have isolated and characterized hundreds
of microbes (fungi, bacteria, and viruses) from Greenland and
Antarctic ice cores that are up to two million years old. Many
of the microbes remain viable and can be cultured. We have characterized
the organisms using morphological and molecular methods. Many
of the microbes are very similar to contemporary species, while
others are different from any organism described to date. We are
investigating whether the ancient organisms interact genetically
with the contemporary members of the same species. We have termed
this process "genome recycling." This interaction has evolutionary implications, as well as important ramifications
for the hosts of pathogenic organisms. For example, if a virulent
form of a disease is released from a glacier, it may be capable
of infecting a population of humans that lack immunity to this
organism. We are studying short-term cycles of influenza A virus
preservation by assaying polar and sub-polar lake ice for subtypes
of this virus. Long term survival in ice could be an effective
evolutionary strategy for microbes on earth, as well as those
that may be present on other bodies within the Solar System and
beyond. One related project involves characterizing microbes from
ice above subglacial Lake Vostok (a lake as large as Lake Ontario).
This lake lies beneath 3700m of glacial ice and has been isolated
from the atmosphere for approximately 10 million years. We have
found DNA and viable microbes in ice that originated in Lake Vostok.
There are two additional projects ongoing in
my lab. The first is a study of an extremely small (67 nucleotides)
group I intron located in the ribosomal RNA small subunit gene
of the pathogenic fungus Phiolaphora americana. The intron has
been cloned and in vitro splicing has been demonstrated. We are
now dissecting the intron and studying its function by mutating
selective nucleotides. Also, the intron has been crystalized and
its structure is being determined by x-ray crystallographic methods,
The second project is a molecular analysis of hospital patients'
blood to determine whether fungi are present. Often, patients
have infections that cannot presently be diagnosed because the
organisms cannot be clinically identified. Our molecular approach
will afford doctors another diagnostic tool to quickly identify
all fungi present in a patient's blood sample, so that treatment
can be selected appropriately and rapidly.
Karen V. Root, Ph.D. (email: kvroot@bgsu.edu;
phone: 419-372-8559)
A MULTISPECIES APPROACH TO ECOLOGICAL ASSESSMENT
AND CONSERVATION
The conservation of ecosystems focuses on evaluating
individual sites or landscapes based on their component species.
I have developed methods to compute the community-level risk of
extinction for a site and assign a multispecies conservation value.
These methods have been applied to several case studies in California,
Florida, and Ohio to create a series of multispecies conservation
value maps. The multispecies conservation value provides an independent
measure of the value of a particular site based on its ecological
components using both the habitat suitability and risk of extinction
for each these species. The resulting maps highlight areas that
are of greatest importance to the most vulnerable species, such
as the remaining forested habitat and critical wetland areas.
These methods are very flexible and can accommodate the quantity
and quality of data available for each individual species both
in the development of the habitat suitability maps and the estimation
of the extinction risks. This method provides an important tool to prioritize conservation and recovery actions,
such as the ongoing Everglades restoration, and evaluate land
preservation alternatives.
ASSESSING THE VIABILITY AND POTENTIAL EFFECTS
OF MANAGEMENT OPTIONS FOR
THE ENDANGERED AND THREATENED SPECIES
Many animal species are becoming vulnerable
to extinction as they face rapid human population growth and the
accompanying pressure for development and land conversion in this
country. My research uses detailed habitat suitability and demographic
data to build stochastic, spatially-explicit, stage-based models
for a number of endangered and threatened species, including the
Florida panther, desert tortoise, shortnose sturgeon, and Florida
Scrub-Jay. Using these models, we explore the long-term viability
of the species, the effects of habitat loss, and potential recovery
options such as natural dispersal and translocation to increase
the number of populations. This ecological risk analysis provides
valuable guidelines for the protection and recovery of these vulnerable
species.
Karen L. Sirum, Ph.D. (email: ksirum@bgsu.edu;
phone: 419-372-3877)
SCIENTIFIC TEACHING LEARNING COMMUNITIES
Although there is a need for continued pedagogical
advancement in biology undergraduate education, what is needed
more urgently is more widespread adaptation of pedagogical practices
that research has already shown promote learning in biology. Those
practices includes interactive engagement pedagogies such as active
learning and inquiry based learning, technology integration in
the classroom to promote learning, authentic learning experiences
and assessment, and the importance of introductory level courses
in recruitment, retention, and diversity of biology majors. The
need now is to find ways to integrate and institutionalize these
evidence-based strategies for teaching science and to help biology
faculty learn about and implement them.
Scientific teaching is analogous to the way scientists approach their experimental
research and is teaching based on evidence about what best promotes learning.
In Scientific Teaching Learning Communities (STLCs), faculty and future faculty
meet in collaborative, interactive sessions to discuss the design and implementation
of interactive teaching strategies that promote student learning and teaching
scientifically. A web-based survey was designed and implemented to assess the
impact participation in STLCs had on faculty participants. This survey reveals
not only which aspects of the professional development program the faculty
found valuable, but also how the program impacted student learning in the faculty
member’s classroom.
PROMOTING AND ASSESSING SCIENTIFIC THINKING
IN GATEWAY BIOLOGY COURSES
Undergraduate science education goals include
development of students’ scientific thinking skills, valuing evidence,
and the propensity to use these skills and values in everyday
decisions. An integrated assessment approach, including the design
and implementation of a new instrument called the Experimental
Design Ability Test (EDAT), is being used to assess learning in
biology courses that aim to bring these skills and values to all
students. The EDAT measures gains in students’ understanding of
the criteria for good experimental design through their open-ended
response to a prompt grounded in everyday life science problems.
A simple and specific scoring rubric is used to analyze student
responses and provides for consistent and rapid evaluation. In
addition to the EDAT, the California Critical Thinking Disposition
Inventory is used to assess gains in students’ disposition to
use critical thinking and the Student Assessment of Learning Gains
survey is used to determine students’ self-reported gains in knowledge, skills, and attitudes in science. Further refinement of the EDAT will
provide a new scientific thinking skills test that may help provide
an answer to the question “How do we know there is learning?”
Eileen M. Underwood, Ph.D. (email: eunderw@bgnet.bgsu.edu;
phone: 419-372-8564)
ALL THAT SLITHERS IS NOT SLIMY
REPTILES ARE "COOL"
A lightweight introduction to the world of
reptiles, utilizing a variety of commonly-kept lizards and snakes
to demonstrate the biology and husbandry of these intriguing animals.
A mixture of native species and exotic pets are used to help dispell
common myths and fears of this unique group of organisms. Animals
utilized will vary depending upon who is "preshed" and therefore less predictable in mood, but may include: corn snakes, royal
python, rainbow boa, grey-banded kingsnake, eastern fox snake,
Dumeril's boa, red-tail boa, leopard gecko, crested gecko, bearded
dragon, blue-tongued skink, box turtle. The subject matter lends
itself to a "hands on" presentation, if desired.
GENETICS AND THE COMMON CORNSNAKE
Corn snakes come in a plethora of colors and
patterns: "red albinos," "black albinos," ghost and snow corns, striped and motley corns. This seminar provides an introduction
to the world of Mendellian
genetics utilizing the
phenotypic differences seen in these commonly kept pet snakes.
Moira J. van Staaden, Ph.D. (email: mvs@caspar.bgsu.edu;
phone: 419-372-0341)
SENSORY PROCESSES AND SPECIATION
Communication between individuals determines
the formation of mating pairs, the genetic structure of populations,
and ultimately, the direction of evolution of both populations
and species. Successful communication depends, in turn, on complex
interactions between the environment, signaling, and sensory systems.
My research examines the proximate neural and behavioral mechanisms,
as well as the ultimate genetic and evolutionary result of communication,
using a unique family of bladder grasshoppers that communicate
acoustically over distances greater than a mile. What selective
pressures drove the origin of the dozen ears these animals possess,
and what impact did this have on the adaptive radiation of the
family as a whole? The evolution of complex structures from simple
precursors remains one of the primary challenges for evolutionary
biology today. Combined approaches using species with highly exaggerated
characteristics provide support for this, as well as insight into
aspects of neural evolution, and the processes by which species become differentiated.
Ron C. Woodruff, Ph.D. (email: rwoodru@bgsu.edu;
phone: 419-372-0376)
PREMEIOTIC CLUSTERS OF NEW MUTATIONS IN THE
EVOLUTIONARY LANDSCAPE
Unlike what is usually assumed, new mutant
alleles do not always arise in natural populations as single events.
Premeiotic clusters of mutation, which give rise to a number of
new, identical mutant alleles in an individual, alter many assumptions
of the role of mutation in evolution. For example, they increase
the probability of fixation of new mutations, and influence the
overdispersed molecular clock, the cost of natural selection,
mutation meltdown and the rate of substitutions. In addition,
these clusters should be included in estimations of mutation rates
and may increase the chance of prezygotic reproductive isolation.
Premeiotic clusters of mutation have been observed in every higher
organism studied, including humans, and give an increased role
for mutation in evolution and human health.
Jill H. Zeilstra-Ryalls, Ph.D. (email: jzeilst@bgsu.edu;
phone 419-372-2872)
GENE REGULATION IN THE PHOTOSYNTHETIC BACTERIUM
RHODOBACTER SPHAEROIDES
The a-Proteobacterium R. sphaeroides has the
ability to harvest both chemical and photonic energy. This remarkable
metabolic versatility is enabled by its ability to synthesize
and assemble the various molecular machineries that are required
for these different catabolic processes, including respiratory
chains and (anoxygenic) photosynthesis complexes. We are investigating
at the level of gene transcription how the cells sense and respond
to changes in their environment, using as our model genes those
whose products catalyze the biosynthesis of the tetrapyrroles
heme and bacteriochlorophyll. These "colors of life" provide us with a window into the cell's physiology, since hemes complexed with
cytochromes are essential components of respiratory chains that
support aerobic energy production, while bacteriochlorophyll is
indispensable for photosynthesis, the means by which these cells
obtain energy in the absence of oxygen and the presence of light.
We know that oxygen is a key environmental input controlling which
catabolic pathway is deployed, and we know that this is mediated
by the action of three DNA binding proteins. Our current efforts
are directed towards understanding how these transcription factors
work singly and in combination to achieve the correct and coordinated
transcriptional response to changes in oxygen availability. We
have also recently begun to examine the means by which the cell
responds to changes in other parameters, such as light intensity,
nutrient availability, and so on. Ultimately, we hope to build
a comprehensive picture of how the cell integrates all regulatory
events to establish the metabolic state that is best suited to prevailing conditions.
|