Since 1987, UMaine biochemistry professor Mary Rumpho-Kennedy has been studying Elysia chlorotica—a tiny “solar-powered” sea slug found in saltwater marshes along the East Coast.
Her recent research offers insight into the potential for evolution of photosynthesis in an animal through symbiosis and gene transfer.
This sea slug looks and acts like a leaf and reacts to sunlight in much the same way as a plant, opening up when exposed to sunlight.
Sea slugs suck out the cellular contents of their algal prey and retain the green chloroplasts in cells lining their digestive gut. This DNA, if not digested, may be either taken up freely floating by cells lining the gut or transferred by some type of vector, possibly a virus. The foreign DNA then becomes part of the animal nuclear DNA, transferring genetic information from the algal nucleus to the sea slug.
With this special type of symbiosis, sea slugs never need to eat again. Instead, they survive for months on sunlight and air—just like a plant—by carrying out photosynthesis.
Rumpho-Kennedy ultimately hopes to discover how the sea slug is able to get the algal DNA into its system and make it work, determine the minimal requirements for photosynthesis, and understand how the foreign material avoids destruction in the sea slug.
Searching for Solutions
Students in UMaine’s Graduate School of Biomedical Sciences (GSBS) collaborate with more than 80 world-class researchers from UMaine and six partners—The Jackson Laboratory; Mount Desert Island Biological Laboratory; Maine Medical Center Research Institute; University of New England; Maine Institute of Human Genetics & Health; and University of Southern Maine.
The springboard for GSBS was a research triangle—UMaine, The Jackson Laboratory and Maine Medical Center Research Institute—that offered the state’s first Functional Genomics Ph.D. Program, funded in 2002 by a $2.6 million National Science Foundation (NSF) Integrative Graduate Education and Research Traineeship (IGERT) grant.
Initial funding for GSBS student support came from the MaineLegislature using scholarship funding from the racino revenues, followed by two years of funding through the Maine Economic Improvement Fund. Funding for the next two years was appropriated by the Legislature as a result of the enhanced Federal Medical Assistance Percentage provided in the 2009 American Recovery and Reinvestment Act.
The program provides up to two years of financial support for students, including $23,000 in stipends, tuition and fees, and health insurance. After their first two years in the program, students complete their education and research at UMaine or a partner institution. The final years are typically supported by external grants from agencies such as NSF or the National Institutes of Health.
Detecting Breast Cancer With Geometry
UMaine assistant professor of mathematics Andre Khalil recently received a grant of more than $73,000 from the Maine Cancer Foundation to build on initial research done by his colleagues in France— Pierre Kestener and Alain Arneodo—concerning use of wavelet-based image analysis to detect tumors and improve early detection of breast cancer.
The Two-Dimensional Wavelet-Transform Modulus Maxima method detects the difference between dense and fatty breast tissue, and reveals microcalcifications. The technology also may be able to discriminate between benign and malignant breast tumors.
Khalil will use the wavelet technology to analyze more than 3,000 images in the online Digital Database for Screening Mammography, maintained by the University of South Florida.
Based on Kestener’s research, Khalil hypothesizes that the software can detect a benign tumor based on its geometry, possibly even before it could be seen by a radiologist. It’s believed that benign tumors are fairly typical in shape—a circle or square. It is when the tumor has a more complex fractal or branch-like structure that it is more likely to become more invasive and, thus, malignant.
Relating Competition and Conservation
Five UMaine professors have joined forces under the leadership of principal investigator James Wilson, professor of marine sciences, to gain a better understanding of the relationship between competition in the fishing industry and conservation.
The project is funded by an approximately $1 million grant from the National Science Foundation. Researchers will look at the way competition among fishermen leads to private incentives and informal social arrangements that are—or aren’t—consistent with conservation of the resource.
These informal arrangements and incentives are important because they can help explain to what extent private interests might reinforce or impair ongoing resource management and, consequently, the sustainability of coupled human and natural systems.
Looking at three Gulf of Maine fisheries—sea urchins, lobster, and cod—researchers will use a computer modeling program to mimic the way those in the fishing industry use their experience to refine their knowledge about their natural and social environment.
Each fishery will be modeled using a biophysical simulator of the natural system and a tightly integrated multi-agent learning classifier system that simulates the learning and interactions of fishermen. The design of each model will be based in part on extensive interviews with fishermen about their knowledge of the dynamics of the fisheries in which they work.
Image Description: SeaSlugs007
Image Description: Lobster Institute