APEX Presentations
November 1, 2006
Phospholipase Da1 Mediated Signaling in Arabidopsis thaliana
Name: Dan Factor
Major: Biochemistry
Academic and APEX Advisor: Dr. Prudence Hall
Location: Donald Danforth Plant Science Center
Dr. Xuemin Wang
Member and Principal Investigator, Donald Danforth Plant Science Center, and
E. Desmond Lee and Family Fund Professor,
University of Missouri-St. Louis
Donald Danforth Plant Science Center
975 North Warson Road, St. Louis, MO 63132
314.587.1419
Swang@danforthcenter.org
Source of Funding: National Science Foundation, as a Research Experiences for Undergraduates (REU) site
Phospholipase Da1 (PLDa1) catalyzes the conversion of membrane phospholipids in to phosphatidic acid (PA). PA levels vary rapidly and transiently in the cell membrane, and act as a second messenger in several agriculturally significant pathways, including abiotic stress response, pathogen defense, cytoskeletal changes and vesicular trafficking. PA is also believed to be involved with abscisic acid (ABA), one of the most studied plant hormones, in the repression of seed germination and maintenance of stomatal aperture. The germination rate of several genotypes of Arabidopsis on ABA media were compared to determine the effect of variation in PA levels on sensitivity to ABAs effects. The results of the germination assays did not show significant difference in percentage or rate of sprouting. Research shows that phytosphingosine-1-phosphate, the product of sphingosine kinase (At4g21540), affects stomatal aperture, and binds to PA in the region between residues 240 and 340. Site-directed mutagenesis was attempted on two putative binding sites in that region to determine if they were involved in the association. The mutation of residues R243, R245 and R247 were not successful; however, the conversion of R281 and K283 to alanine had no effect on the binding of PA and sphingosine kinase.
Presence and Localization of Surfactant Protein-A in Relation to Menstrual Cycle
Name: Razan Yasin
Major: Biology
Academic Advisors: Dr. Dennis Taylor and Dr. Sandy Madar
APEX Advisor: Dr. Brad Goodner
Location: Penn State College of Medicine/ Penn State Milton S. Hershey Medical Center
Dr. Colin MacNeill
MD and Assistant Professor of Obstetrics and Gynecology
Penn State College of Medicine
Hershey, PA 17033
717.531.5994
cmacneill@psu.edu
The endometrium, which is the inner lining of the uterus, is known to be a key player in the menstrual cycle and proper embryo implantation, but it is also the first line of defense against uterine infection. The interest in research is how this tissue fights infection and still tolerates the implantation of this foreign body; the embryo. An attempt to try studying this phenomenon is to study an immune protein, in this case, Surfactant Protein-A. It is hypothesized that SP-A is differentially produced through the menstrual cycle. Uterine biopsies were obtained from 17 healthy women. Immunoreactions were carried out using antibodies recognizing SP-A, and an RT-PCR reaction was done to further verify the presence of SP-A. SP-A was shown to be found in the endometrium in all phases of the menstrual cycle, with a variation of its localization in the different phases. Genes of SP-A were also transcribed in the endometrium. Finding proteins like SP-A in the endometrium helps identify their function and later expand our understanding of the implantation, and the problems that go with it such as abortion or preterm.
The SUN locus of Lycopersicum – what does it do and where does it act?
Name: Lucas Tomko
Major: Biology
Academic and APEX Advisor: Dr. Matthew Hils
Location: Ohio Agricultural Research and Development Center (OARDC)
Ester van der Knaap
Principal Investigator/Researcher
Department of Horticulture and Crop Science
204A Williams Hall
The Ohio State University/OARDC
Wooster, OH 44691
330.263.3822
Source of Funding: OARDC
Domestic tomatoes have become diversified in many ways from an ancestral small and round phenotype. One of the major genes governing an elongated phenotype in several domesticated species is the SUN locus. Using paraffin- and plastic-embedded microtome sections of early fruits and buds of nearly isogenic lines (NILs) of tomatoes, a microscopic analysis of cell morphology and number was carried out to determine a mode of action for the SUN gene. Simultaneously, a transient assay known as Agroinfiltration was performed to determine if SUN is localized in the nucleus, narrowing its possible affects on fruit shape. Results suggest that when SUN is present septum cells are most elongated, however, fruit wall cells are generally smaller. No conclusive results emerged from the nuclear localization experiments and steps are being taken to ensure that SUN is not nuclear localized, but rather may be active in the cytoplasm. One explanation of the longer septum cells is a timing issue related to a biological clock governing septum elongation during development. This interpretation would also possibly explain why all of the fruit wall cells are smaller since they are under increased stress from the force exerted by longer septum cells.
Manatee Field Research
Name: Dawn Sechler
Major: Biology
Academic and APEX Advisor: Dr. Dennis Taylor
Location: Mote Marine Laboratory
Ester Quintanno Rizzo
Senior Biologist
Mote Marine Laboratory
1600 Ken Thompson Parkway
Sarasota, FL 34236
727.642.9011
equintana@mote.org
As an intern in Mote Marine Laboratory’s Manatee Field Research Program, I participated in a life history long-term study where I photographed individual Florida manatees (Trichechus manatus latirostrus), recorded environmental conditions and behaviors. This internship also consisted of lab work, updating the sighting data sheet database, effort log, and image log database. The image log was used for photo-identification. The conclusions of this life history long-term study are: 1) manatees are site specific 2) manatees have a negative relationship with humans 3) a positive relationship is shown between age and scar pattern. The continuation of this study will help build supportive evidence for areas that need stricter boating regulations in order to protect the manatees and their environment.
The Effects of Green Frog (Rana clamitans) Presence on American Toads (Bufo americanus)
Name: Erin Sams
Major: Biology
Academic and APEX Advisor: Dr. Dennis Taylor
Location: Miami University (Oxford, Ohio)
Dr. Michelle Boone
Assistant Professor, Department of Zoology
212 Pearson Hall
Oxford, OH 45056
513.529.4901
boonemd@muohio.edu
Source of Funding: National Science Foundation (Research Experience for Undergraduates)
Many research studies have focused on the interactions among larval anurans, but relatively little is known about competition and potential predation among postmetamorphic anurans. The purpose of our study was to examine the effects of postmetamorphic Green frogs (Rana clamitans) on postmetamorphic American toads (Bufo americanus) in the terrestrial environment. Through analysis of adapted anti-predator avoidance strategies, we examined the survival, growth, and behavioral responses of recently metamorphosed American Toads in a replicated laboratory experiment with three treatments: 1) exposed to a caged Green Frog, 2) exposed to a free-roaming Green Frog, and 3) no Green Frog (control). Green Frog presence had a significant negative effect on American toad survival in the free-roaming treatment. Our data also reveals trends that suggest negative effects on mass gain and activity in both Green Frog treatments when compared to the control. These results indicate that Green Frogs do exert significant effects on American Toads in the postmetamorphic terrestrial phase, but do not indicate whether the effects are due to predation or competition for resources. The Green frogs are much larger than the American toads, which inhibits mass gain in the toads as a result of their lesser competitive strength. Further research is necessary to examine the nature of these effects.
Genitalia Dissection and Redescription of Prionapteryx nebulifera
Name: Stephanie Larrick
Major: Biology
Academic and APEX Advisor: Dr. Brad Goodner
Mississippi State Entomology Museum
Dr. Richard Brown
Director of Mississippi Entomological Museum Address: Box 9775
Mississippi State, MS 39762-9775
662.325.2085
moth@ra.msstate.edu
This past summer I had the privilege of doing an internship at the Mississippi State Entomological Museum. The museum was founded in 1979 and contains over a million species with 35,000 being added annually. One project that I took on was dissecting the genitalia of the male and female Prionapteryx nebulifera (Steph) for the species redescription. Genitalia are unique to each species in the order Lepidoptera, so using genitalia dissection is a great way to distinguish species. Once dissected and mounted, I made scale drawings of the genitalia. The drawings are going to be used by Edda Martinez, from Mississippi State University and a colleague in Canada. Having the opportunity to work at the Entomology Museum was a valuable experience that has helped shape my outlook on my career field.
Functional Genomics: Characterizing Biofilm Mutants
Name: Lindsey Wilson
Majors: Biology and Theater
Academic and APEX Advisor: Dr. Brad Goodner
Location: Hiram College Genetics Lab
Dr. Brad Goodner
Professor
Hiram College,
Hiram, OH 44234
330.569.5260
goodnerbw@hiram.edu
In forward functional genomics, mutations are introduced into a population of cells and then a particular phenotype is screened for and the disrupted gene isolated, sequenced and identified. Here we screened for and isolated four biofilm mutants in the soil bacterium and plant pathogen Agrobacterium tumefaciens C58, HCA 40, HCA 41, HCA 61, and HCA 82. Along with isolating and sequencing the mutated genes, these four mutants were further characterized by visual inspection of individual colonies, inspection of pellicles under the microscope, binding assays, growth curves, and virulence assays. The most striking difference found between the mutants and wildtype, was the appearance of their pellicles. Wildtype appeared very tightly bound and the mutants, more mucous-like and loosely bound. The mutated genes were identified as adenosylmethionine-8-amino-7-oxononanoate amino transferase (bioA), structural gene (exoY), conserved hypothetical protein, and fructosebisphosphate aldolase, respectively. I will discuss the potential connections between the functions of these genes and biofilm formation.