Biology

Undergraduate Research

Waldorf C O L L E G E

Over 3000 hectares (7500 acres) of wetlands have been restored in Winnebago County, IA – like “islands in an ocean of agricultural land.” How quickly will amphibians find these new “islands” and what landscape features facilitate their movements? Using a combination of radio-telemetry, genetic analysis, biophysical models, a Global Positioning System, and a Geographic Information System, we learned that frogs and toads take 1-3 years to find new wetlands, depending on the location of new wetlands from older ones. We also learned that frogs travel through agricultural fields far less than toads and follow different paths to find new wetlands. This work was funded by the U.S. Geological Survey, the Iowa Science Foundation, and the Hanson Foundation. Its results have been presented at national conferences of The Wildlife Society and the Joint Meeting of Ichthyologists & Herpetologists, and the Iowa Academy of Science.

Tumor suppressor genes prevent cancer in normal body cells. When cancer occurs, tumor suppressor genes are frequently found to have been lost, damaged, or turned off. NIAM is a newly discovered potential tumor suppressor gene that may prevent cancer by preventing cells from accumulating damage in their chromosomes. My research focused on two questions about NIAM’s role normal and cancer cells. First, are NIAM levels really reduced in Glioblastoma (a kind of brain tumor)? I obtained tissue samples from surgeries on Glioblastoma patients and measured NIAM mRNA levels relative to levels in noncancerous neural tissue (from epilepsy patients). I showed that NIAM mRNA levels were significantly reduced in 67% of glioblastomas. Second, I assisted in breeding and characterizing mice in an effort to produce a line of NIAM knockout mice. Knockout mice help determine the roles genes play in physiology and disease. I identified several mouse pups which had one allele of NIAM knocked out. These mice can now be bred with each other to produce double allele knockouts. Both the single and double knockouts will be studied for increased susceptibility to glioblastoma and other cancers. Data from these studies has been presented in talks and a poster session at the University of Iowa Carver College of Medicine, and have been incorporated into an RO1 grant application for research funding from the National Institutes of Health.

Staphylococcus aureus is a commonly occurring bacterium on human skin that can cause serious skin infections when it enters scrapes or other wounds. Methicillin resistant S. aureus (MRSA) is especially problematic because it is resistant to many antibiotics. Persistent incidence of Staphylococcal infections among Waldorf College wrestlers in recent years prompted me to ask: 1) What is the source of S. aureus producing wrestling associated infections, and 2) Are the S. aureus bacteria that are afflicting wrestlers developing resistance to the skin disinfectant benzethonium chloride? I swabbed the skin of participating wrestlers, their clothing, equipment, and surfaces in wrestling and locker rooms, then cultured them 48 hours in media selective for Staphylococci. Resulting cultures positive for growth were streaked on mannitol salt agar plates to confirm whether they contained S. aureus. Results indicate the primary source of S. aureus to be on or about the wrestlers’ heads. The most prevalent secondary source was headgear. Results were presented in Waldorf’s Inquirere seminar series. Ongoing studies include characterization of a strain of MRSA isolated from an infected wrestler, and efforts to identify new antimicrobials that would be effective against this strain of MRSA.

Zoos are key to educating the public about wildlife conservation and maintaining captive populations of wildlife. To facilitate the health and natural behaviors of these animals, zoos must understand their normal social behaviors and activities. Our goal in on-going study is to better understand female dominance hierarchy within a troop of Japanese macaques at the Minnesota Zoo, and how rank influences social relationships. We focused on dominant and submissive behaviors to estimate hierarchy and to quantify the troop’s activity budget. The results will allow zoo managers to design better enrichment activities and allow successful interactions among members of two different macaque troops.

Cells in our bodies coordinate their normal growth and activities by producing and responding to chemical signals. When normal signaling is altered, cancers can develop. Excessive Wnt signaling is often implicated in colon and other cancers. Triptolide and iron binding small molecules inhibit Wnt by blocking beta-catenin mediated transcription. We pursued two different approaches of study to better understand how each molecule works. The National Cancer Institute (NCI) accepted our molecules into a screening program that examined toxicity of these molecules and their ability to inhibit growth in 60 different cancer cell lines. With this NCI data, we identified compounds with known mechanisms of action that had similar toxicity or growth inhibition profiles. We also found genes whose expression levels correlate with relative toxicity or growth inhibition of each compound. Preliminary results indicate that triptolide functions as a general inhibitor of gene transcription, and that compounds which bind to iron do not all exert their anticancer effects via a common mechanism. In our second approach, we introduced a tagged TCF4 gene into a colon cancer cell line and selected for clones of cells that stably express the tagged protein. These cells allow the beta-catenin/TCF transcription complex to be purified so that proteins which participate in the complex in the presence or absence of a drug can be identified. This on-going work was presented in Waldorf’s Inquirere seminar series.

When one wishes to follow the movements and daily habits of wild animals, there is no substitute for radio-telemetry. Attaching miniature radios to frogs and toads for an entire season is difficult, however, because their skin is thin and delicate. And, different features of frogs and toads require different attachment methods. We developed an effective method for attaching radios to both frogs and toads for months (the life of the radio). This work was funded by the U.S. Geological Survey and will appear in Herpetological Review in spring 2012.

In the latter 1990s, Winnebago County residents were concerned about how large livestock confinements might affect water quality in the County. In response, we began sampling water several times a month from 20 different sites scattered across the County for levels of nitrogen (ammonia and nitrates), phosphates, salts (chloride), and oxygen. After 10 years, we found that where producers were careful, nutrient levels changed slightly. At other sites, however, levels of nitrates doubled or tripled, phosphates doubled, chloride increased substantially, and dissolved oxygen levels dropped. Our work was funded by the Winnebago County Board of Supervisors and resulted in cleaning up two point sources of pollution and encouraged the planting of additional buffer strips along streams.

Since the mid-1990s, studies have focused on the movements and daily habits of amphibians. In the latter ‘90s, we used radio-telemetry, a Global Positioning System, and a Geographic Information System to follow the movements of Northern leopard frogs on the Union Slough National Wildlife Refuge (Kossuth County, IA). Many frogs left the Refuge after breeding and used road ditches and grassy surface drainage-ways of adjacent agricultural lands. This work was funded by the U.S. Fish & Wildlife Service (FWS) and was the first “Challenge Cost-share” study in Region 3 of the FWS. Results of this study were presented to the Iowa Academy of Science and Iowa Chapter of the Wildlife Society and were integrated into the Refuge management plans.

In 1983, trees on the Medicine Bow National Forest (Wyoming) were cut to the very edges of some ponds, contrary to recommendations of the forest Biologist. Because these ponds were used for breeding by a relict population of Wood frogs, we tested how this logging affected the population of frogs. Removal of protective canopy from around these ponds raised mortality of developing eggs and larvae up to 70%. The study was funded by the U.S. Forest Service and led to strengthening protections of wetlands in timber harvest areas. It also initiated annual amphibian surveys on the Forest.