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GSOLS Connelly Lab
Rochester Institute of Technology College of Science
Where are they now?
Research proposal pursued: UV radiation causes extensive damage and mutation to an organism’s DNA, and with an increases of UV levels in freshwater ecosystems, it is important to explore the effects this phenomenon is causing. This project will focus on the extent of damage and ability of DNA repair after Daphnia species experience exposure to UVA and UVB radiation. The Various daphnia species have been exposed to different types and duration of UV radiation. DNA samples were taken before exposure, immediately after exposure, and after a recovery period. Now that exposures and DNA has been collected, the work of this semester will be to develop an ELISA protocol to measure the amount of mutations in each sample and compare these values. The knowledge obtained from Daphnia can be used as a model for freshwater ecosystems as a whole. Knowledge of UV radiation’s effects will be significant in understanding changes in freshwater ecosystems that may occur as environmental changes continue. It is important to understand not only survival and mutation rates of organisms in the presence of UV but to also the ability to recover. This data will illustrate the varying abilities to repair and levels of adaptability of different species of daphnia as they face increasingly high amounts of UV radiation in their freshwater ecosystems.
Research proposal pursued: Objectives: Determine the anti-predator defenses of Jefferson salamanders on RIT campus and observe correlations between salamander length, color, flight response, tail lift. Kate studied the anti-predator behavior of RIT Jefferson salamanders to find unique relation between their tail responses and physical attributes. She located salamander habitats on RIT campus and performed field data collection of: salamander location, quantity of salamanders at specific site, initial uncovering response (stationary or flee), perform predator behavior stimuli (three count tap), measure body proportions, photograph salamanders for coloration scale. She quantified salamander tail responses include: tail lift below 45 degrees, tail lift above 45 degrees, wriggle, a combination of lift and wriggle, or none and performed statistical analysis of data to determine exact relationship of anti-predator responses. Kate is a co-author on a manuscript in review at American Biology Teacher (June 2016).
Zach Kopp & Robby Keith
Research proposal pursued: Zach and Robby worked together on the following project: Problem: Understanding the role of Vitamin D in aquatic ecosystems, particularly the connection between algae and microinvertebrates. The study of vitamin D3 sequestration in Pseudokircheriella algal biomass will assist collaborative research efforts involving the bio-indicator species, Daphnia pulex. Previous work at the RIT research labs of Connelly, Tan, and Cody has been focused on exposing Daphnia to UV radiation and monitoring the photo-properties of vitamin D3 or the internalized metabolite, 25-hydroxyvitamin-D3. This work will be a continuation of the prior experimental trials, involving the use of fluorescent-labeled compounds of Vitamin D (Cody lab). Previous experimentation showed that under the stress of UV-A, the algae was shown to be hungry for a much larger proportion of the added vitamin D3 than that of the Daphnia. Prior studies have shown that there is a more complex role than expected with the mitigation involving the system of antioxidant uptake and UV irradiation by algae in an aquatic system. Experimentation will include multiple varieties of algal species. Photos of selected algae species are to be taken, in vivo, to determine the location of the vitamin sequestration in the algal body. This continuation is a critical expansion of previous phases of this project and will aid in determining the effects of vitamin D3 on the aquatic ecosystem. Zach and Robby are co-authors on a manuscript published in PLOS ONE (http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0131847)
Steven imaged Daphnia as part of the vitamin D3 project using scanning electron microscopy (SEM). He is a co-author on a manuscript published in PLOS ONE (http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0131847)
Research proposal pursued: Increased levels of ultra-violet radiation have been shown to have detrimental effects on numerous organisms. Therefore, the possibility of photo-protective compounds is increasingly appealing. The focus of this project is the potential photo-protective properties of vitamin D3 in the freshwater micro-crustacean, Daphnia. I hypothesize that vitamin D3 will increase the fitness (survival and reproduction) of Daphnia exposed to UV radiation, both long wave or UV-A, which emits at 400-315nm, and medium wave or UV-B, which emits at 315-280nm. Kelly was part of a collaborative research project that included Dr. Connelly, Dr. Cody, and Dr. Tan labs at RIT. Her side of the project revolves around studying the Daphnia. During summer of 2011 she ran experiments testing the overall health and viability of Daphnia pulicaria under UV and non-UV conditions. Daphnia spp. were raised on fixed concentrations of vitamin D3 (0- 3,000 ng ml-1) and exposed to UV-A radiation (0 - 60 kJ m-2). Control populations (ones with no UV exposure) were compared to populations under variable conditions. The data conclusively showed that Daphnia given vitamin D3 could survive higher doses of UV-A radiation. Her focus was on the effects of vitamin D3 in respect to UV-B exposure. Her project was significant because reduction in Daphnia populations have been shown to have higher food web impacts. Kelly is a co-author on a manuscript published in PLOS ONE (http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0131847)
Research proposal pursued: The continual depletion of the Earth’s stratospheric layer has led to a higher amount of ultraviolet (UV) rays reaching the Earth’s surface 1, severely affecting the global climate, and forcing many organisms to develop mechanisms to survive.2 UV radiation is absorbed by DNA in all organisms and can cause lethal genomic mutations. Because organisms cannot survive high levels of DNA damage, populations must find ways to protect themselves. An organism’s ability to survive stressors will depend on the types and number of mutations induced in their genome. In freshwater organisms, physiological and behavioral changes such as migrating (swimming) away from areas of higher UV exposure or increasing their DNA repair rates to compensate for increased damage, will be triggered by internal mechanisms.2 Daphnia, a freshwater microcrustacean, is a particularly good study organism because they are transparent (potential for high levels of direct DNA damage), are easy to rear in a lab, and are found in most freshwater systems in nearly all climates. Daphnia are parthenogenic organisms (females asexually reproduce female offspring)3, providing a unique opportunity to observe the behavioral and physiological changes in these organisms over many generations without high levels of genetic variability that would be typically observed in sexual organisms. Food availability is known to have significant effects on growth rates in Daphnia, so the appropriate amount of the algal food source was determined to maintain a high fitness level (survival and reproduction). The amount of the algae Selenastrum required to survive and reproduce steadily is 2.0mL D. magna reproduction appear to be unaffected by the different UV-A treatments. D. magna appear to be unaffected by the acute UV-A dose to which they were exposed; D. pulicaria appears to be affected by the dose; D. pulex is significantly affected by increasing acute UV-A in this experiment under both food types.