Browse the Biology/Ecology Collections
Molecular Evolution of Immune Epitopes in Ebola Virus (EBOV, Filoviridae): Insights Into Host-Pathogen Interactions03/21/2017The purpose of this project is to analyze the evolution of the Ebola virus. After the latest outbreak enough Ebola strains have been sequenced to allow a through evolutionary study. Comparing patterns of mutation in regions that have been identified as epitopes to non-epitope protein regions will allow conclusions to be drawn regarding Ebola’s interaction with the human immune system and whether it will remain a deadly acute disease. If the regions have a universal level of mutation, then there is no sign of immune pressure. This means that the virus is not changing in response to interaction with the human immune system. If this is the case, Ebola will remain an acute infection and probably a very deadly one. However, if there are patterns of higher rates of evolution in epitope regions Ebola may become more acclimated to humans and transition to a less fatal or chronic disease. This behavior is seen in influenza where a highly virulent strain often evolves to be less deadly. There is evidence already that Ebola can be an asymptomatic infection in some cases. The reservoir of the Ebola virus is still unknown. Whether the virus is an acute or chronic infection in its reservoir is also unknown. If it is a chronic disease in its reservoir host then it has the ability to become chronic in humans. Thus, I am mapping point mutations in the Ebola virus protein and ascertaining whether or not these mutations are in regions of structural or antigenic importance. |
Mechanisms of alternative splicing of Vascular Endothelial Growth Factor in hypoxia03/21/2017Vascular endothelial growth factor (VEGF) promotes angiogenesis. VEGF has different isoforms with different functions that are generated by alternative splicing (AS).There are several proteins that participate in splicing, including serine-arginine-rich splicing factors (SRSF).SRSF are activated by kinases such as serine arginine rich protein kinases (SRPKs). Hypoxia has been shown to upregulate VEGF in several cancers. Others have demonstrated that hypoxia up-regulates SRSF proteins, which subsequently increases just the VEGF 121 isoforms in endometrial carcinoma cells. We previously showed that in hypoxic leukemia cells VEGF isoforms were spliced differently and VEGF 121 levels were inversely correlated with levels of WT1, a transcription factor. In acute lymphoblastic leukemia cells, VEGF165 and WT1 were significantly increased by hypoxia. In chronic myelogenous leukemia cells, hypoxia increased both VEGF165 and VEGF121 levels with little change in WT1 levels. Since others have shown that WT1 suppresses SRPK1 levels in sarcoma cells, our data in leukemia cells were consistent with an inverse relation between WT1 and VEGF 121 levels. The aim of this study was to determine if hypoxic conditions activated SRPK1/SRPK2 in leukemic cells to alter splicing of VEGF isoforms. The results indicated that hypoxia does not change mRNA levels of SRPK1/SRPK2, although protein levels need to be examined. Another possible explanation could be that other splicing kinases may be responsible for altering the VEGF 121 levels in leukemia cells. A better understanding of the mechanism of AS of VEGF could lead to new therapy targeting specific isoforms. |
Expression of RACK1 and APP is increased in human Down syndrome fibroblasts03/21/2017Down syndrome results from the trisomy of human chromosome 21 and is the most prevalent genetic cause of intellectual disability. Down syndrome results in various developmental changes that can be observed on a cellular level, including a change in the expression of certain proteins. Because receptor for activated C kinase 1 (RACK1) and amyloid precursor protein (APP) have both been implicated in the pathogenesis of Down syndrome and play a role in cell adhesion and motility, we hypothesized that their expression may vary in Down syndrome. Fibroblasts were obtained from a human diagnosed by karyotype for Down syndrome and a healthy human subject that was age, sex and race matched to the individual with Down syndrome. RACK1 and APP expression in these fibroblasts were labeled using quantitative immunocytochemistry. Preliminary results demonstrate that both RACK1 and APP are overexpressed in Down syndrome fibroblasts. Thus, it is likely that the overexpression of APP and RACK1 in Down syndrome may lead to inappropriate cell adhesion and motility, and contribute to the pathogenesis of this disorder. In future experiments, we will examine how RACK1 mRNA localization may be dysregulated in Down syndrome. In addition, the expression of APP and RACK1 in Down syndrome neurons, instead of fibroblasts, will be examined to further understand how these proteins contribute to the formation of brain connectivity. These experiments will further advance the understanding of Down syndrome, its connection to Alzheimer's disease, and aid in the development of treatments for these disorders. |
Examining the Effects of Road Salt Usage on Pond Snails03/21/2017Deicing salts are commonly applied during the winter months to prevent roads and sidewalks from freezing and increase traction. Once dissolved in run-off, dissociated chloride ions can rapidly enter aquatic ecosystems, leading to increased salinity that can be toxic to aquatic macroinvertebrates. Macroinvertebrates are crucial organisms at many trophic levels within aquatic ecosystems, and these organisms are sensitive to elevated salinity. By impairing macroinvertebrate communities, increases in salinity caused by salts threaten entire aquatic ecosystems. The purpose of this study was to assess the effects of deicing salt on the salinity of five freshwater ecosystems on the campus of Kent State University. Additionally, chronic toxicity tests assessed how pond snails (Lymnaea stagnalis) tolerated these levels of salinity. We hypothesized that the increased concentrations of chloride ions would negatively impact pond snail growth and survival. Water samples from five locations were collected following a snow event and were measured for conductivity and ionic content. Individual snails (1-3 days old) were introduced to these water samples, and growth and mortality were monitored over a period of four weeks. Preliminary data indicates a correlation between road salt usage and increased levels of chloride in Kent waterways. |
Evaluating Stereoscopic Effects with EEG of Memory Formation and Regional Brain Activity03/21/2017A current line of research is focusing on the processes of spatial learning. Previous studies have indicated that students have trouble learning concepts which have a spatial component to them. Topics such as molecular geometry within the field of chemistry are notably difficult. Recent research has suggested that stereoscopic presentation of these objects may promote better learning. To understand the processes which contribute to spatial learning a neurophysiological approach is necessary. Therefore, in order to investigate the effectiveness of stereoscopic presentation and the neural correlates of it, an Electroencephalograph (EEG) was used. Participants were fitted with an EEG cap and had electrical scalp activity recorded using Brain Vision software. Participants were presented with images in both 3-D and 2-D of the organic molecule Hemoglobin. During the tasks, the molecule rotated across three different planes, changed colors, and changed focal distance. The data collected was then analyzed using EEGLAB for MATLAB. Individual components associated with visual processing (visual cortex), executive processing (pre-frontal cortex), and memory (hippocampus) were identified using an Independent Components Analysis (ICA) and dipole modeling. The brainwave activity in these components were recorded and the components were correlated with one another. |
Effects of stream quality on insect-gut associated denitrifying bacteria abundance03/21/2017Gut bacteria in macroinvertebrates in streams and rivers contribute to nitrous oxide (N2O) emissions from these systems through partial denitrification. Denitrification is an anaerobic microbial process which converts nitrates (NO3−) to dinitrogen (N2), removing excess nitrogen from these ecosystems. Poor stream quality negatively impacts the diversity and abundance of certain macroinvertebrate taxa, such as stoneflies, mayflies and caddisflies. The objective of this project was to quantify the abundance of gut-associated denitrifying bacteria in insects from freshwater bodies that differ in quality (Tinker’s Creek, TC and West Branch of the Mahoning River, WBM) and determine if stream quality impacts both insect taxa, as well as gut-associated denitrifying bacteria. Samples of insects, water, and biofilms from debris were collected from these streams. Stream quality impacted macroinvertebrate taxa, with more sensitive insect taxa present in WB relative to TC. Four insect families, Chironomidae, Elmidae, Hydropsychidae and Cambaridae were common in both streams. The insect family Lestidae was only found in TC and Baetidae, Perlidae and Empididae were only found in WB. Bacterial 16S rDNA, and the denitrification genes nirK and nosZ were detected in all samples. This will be followed by quantitative PCR (qPCR) to determine if stream quality also impacts gut-associated denitrifying bacteria among the insect taxa common to both streams. |
Effects of elephants on vegetation along a fenceline contrast in South Africa03/21/2017We assessed the degree of damage of two common plant species, marula Sclerocarya birrea and the mountain aloe or flat-flowered aloe Aloe marlothii in two neighboring game reserves along a fenceline with respect to the presence of African elephants Loxodonta africana. One of these reserves, Thornybush, had 40-50 elephants while the other reserve, the Wits Rural facility, contained no elephants, although elephants had broken into a select region briefly during a recent drought. We measured the browse height of S. birrea relative to overall tree height and trunk circumference to establish the differences among the three different areas. We also measured the presence/absence of A. marlothii in these game reserves. We found no A. marlothii in the reserve with elephants, while this plant species was quite common where there were no elephants, despite the absence of soil differences. In the section of the Wits Rural facility where the elephants had broken in, there were considerably more damaged A. marlothii than in the scetion of this reserve without elephants. We also established the association between the size of the aloe and elephant consumption. |
Dung beetle diversity and species richness across three habitats in South African savannah03/21/2017We examined dung beetle diversity and richness at the Wits Rural Facility in Limpopo Province, South Africa. The dung beetle community was assessed in three separate habitats: grassland, woodland, and the ecotone. For our experiment one kilogram of cow dung was placed at each of 10 locations in each habitat, with samples located 25 meters apart. This was done on two different occasions, once to measure species diversity and the other to measure species richness of the dung beetles that came to each pile. Diversity was measured by collecting one individual of each morphotype at each site. The collection of specimens was done the day the dung was put out and after 24 hours. We counted 26 different morphotypes from the two days combined. Several morphotypes were unique to the second day and were not present on the first. Species richness over time was measured by going out to the dung pile locations during different times throughout the day. We went out to view an hour after the piles were placed in the morning, four hours later at midday, and two hours after that in the early evening. We counted the number of beetles from each morphotype at each location. The number of morphotypes, and density of individuals of each morphotype, decreased over time as the dung piles decreased in volume. |
Does Cx43 Modulate the Motility of Prostate Cancer Cells03/21/2017Prostate cancer (PC) is one of the most common male cancers in United States. PC lethality is due to metastatic growth, when cancer cells move from the primary tumor site to a secondary site. A key step is the acquisition of motility. Connexins (Cx) play a major role in cell-cell communication and contribute to motility. Cx43 is up-regulated in cultured PC3 metastatic prostate cancer cells. To understand the role of Cx43 in migration we asked whether silencing Connexin 43 would decrease PC3 cell migration. Using cells in which short interfering RNA (si-RNA) silenced Cx43 mRNA, we showed that silencing Cx43 decreased motility of si-Cx43 PC3 cells in Boyden chamber assays. To confirm these results in another biological system, we performed cellular wound healing assays. Silencing Cx43 decreased motility of PC3 cells reducing movement to wounded area, leaving more area open in the Cx43 inhibited cell lines. These results supported those of our Boyden assays showing that loss of Cx43 decreases the migration ability of PC3. Next we asked whether overexpression of Cx43 in LNCaP cells, non-migratory prostate cancer cells that lack Cx43 expression, would increase their motility. Currently we are working to engineer Cx43 expression in a modified LNCaP cell line. A comparison of cell lines engineered to overexpress or to silence Cx43 will confirm the importance of Cx43 in the motility of prostate cancer cells in vitro. Cx43 relevance will later be tested in vivo and could lead to new targeting strategies for men suffering from metastatic prostate cancer. |
Comparison of Self-Directed & Social Behaviors amongst a Captive Group of Mandrills (Mandrillus sphinx)03/21/2017Mandrills (Mandrillus sphinx) are social and group-oriented primates. Like many primates, mandrills utilize self-directed and social behavior, but the function of these behaviors in this species is poorly understood. Broadening the knowledge of mandrill behavior could lead to more information on many other primate species including Homo sapiens. In this project the mandrills of the Cleveland Metroparks Zoo were observed to better understand the role of these behaviors. Each self-directed and social behavior of the four individuals on exhibit –Linus (α ♂), Woody (♂), Eebi (α ♀), and Zenani (♀)—was identified and compared to refine comprehension of the social hierarchies amongst a given captive group. Hypotheses formed were: (1) males will exhibit more self-directed behaviors than the females; (2) individuals with higher social rank will exhibit less self-directed behaviors; and (3) there will be a higher rate of self-directed behavior post-conflict. Results found that none of these hypotheses could be supported either due to small population size or misconceptions on complex social animal behaviors. Key words: Mandrills (Mandrillus sphinx); self-directed behavior; social behavior; gender; social hierarchy; |