HHMI Life Science Freshman Research Scholars

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Recent Submissions

  • Publication
    Effects of L protein on MreB and cell lysis
    (Oklahoma State University, 2018-04-19) Templon, Alannah; Karthik, Reddy; Young, Ry
    The MS2 bacteriophage is a single-stranded, positive-strand RNA virus that contains four genes: mat, coat, rep, and L. The L protein is responsible for cell lysis, although relatively little is known about its mode of action. Unlike other viral lysis proteins, which inhibit cell wall synthesis at the division site causing midcell blebs, L protein appears to cause lysis at random cellular locations, as seen by bleb formation throughout the cell. We hypothesized that L protein works with MreB, an essential protein for cell wall synthesis, which is localized throughout the cell body. We seek to identify how L protein affects MreB by possibly: causing the mislocalization of MreB at specific sites of lysis, activating a section of MreB to form a hotspot for cell wall synthesis, or deactivating a section of the MreB pool, causing cell defects. To begin to determine which mechanism is correct, we will measure the localization of MreB in cells undergoing lysis to see if there is a correlation between MreB localization and L protein induced lysis. We will then examine if there is a direct interaction between L protein and MreB using biomolecular fluorescent complementation. Learning how L protein lyses cells will provide us with a better understanding of single gene lysis, which can be applied to phage therapy to kill disease causing bacteria and to effectively prevent bacteriophages from killing helpful bacteria that assist in preventing disease or are important for industrial purposes.
  • Publication
    Phylogeny of Sonoran Desert milkweeds resolved with plastid genome sequences
    (Oklahoma State University, 2019-04-27) Gentry, Shelby
    The Sonoran Desert Clade milkweeds have very unusual traits, including species that are nearly leafless and shrubby. This clade includes 9 species for which we estimate a phylogenetic tree and use this information to better understand why species within this clade are diverging from their ancestral species. To do this we use plastid genomes to find genetic differences among the species. We assembled and aligned plastomes for multiple individuals of each species and found the maximum likelihood phylogenic tree. From the results we found that the Sonoran Desert Clade forms one clade rather than multiple. We found interesting relations between some of the species within the Sonoran Desert Clade. There was hybridization that we found within the results. This will help us further our study on the evolution of the Asclepias species.
  • Publication
    Effects of paternal deprivation on nestling zebra finches (Taeniopygia guttata)
    (Oklahoma State University, 2019-04-27) Giddens, Emily
    Early interactions between parents and offspring have been shown to influence behavior development in avian offspring, which links to their fitness as adults. In bi-parental species, previous research has looked at what developmental alterations have occurred when the mother is removed from the nest during the developmental stage. By looking at the behaviors of the offspring when the father is removed during the nestling stage, we can better understand where the developmental alterations are stemming from. In this study, zebra finches were assigned to control and paternal removal groups, and from post-hatch day 1 through 18, we quantified important parent-offspring interactions that occurred during 1-hour long video recordings inside nests. We are still in the process of quantifying behaviors from all 19 nests, but we expect that the mother will attempt to compensate for the lack of paternal care in the paternal removal group, but not be fully successful. As a result, offspring will have fewer interactions with a parent in the paternal removal group. Determining the effects of paternal deprivation during the nestling stage will allow us to further understand the importance of bi-parental care during development.
  • Publication
    Dying light: Detecting tree mortality risk with chlorophyll fluorescence
    (Oklahoma State University, 2019-04-27) Giddens, Megan
    Increased greenhouse emissions have altered Earth's climate, resulting in rapid climate change which has brought warm droughts-especially in semi-arid regions-leading to forest die-off and dieback. Physiological stresses associated with climate change pose a great risk to tree survival, as future climate changes are likely to increase the intensity of drought. Some of these effects can be observed in species such as pinon pine (Pinus edulis), which typically have a high drought tolerance but have succumbed to widespread drought-induced mortality in recent decades, likely due to hydraulic failure. Currently, remotely sensing hydraulic failure is not possible. However, our results suggest chlorophyll fluorescence in dark-adapted samples is an indicator of water stress and the variation of chlorophyll fluorescence within a tree increases as drought stress prolongs. With continued observation, we believe chlorophyll fluorescence will show to be a useful proxy for hydraulic failure to aid mortality predictions as well as predict how future climate changes will impact terrestrial vegetation and climate feedback loops.
  • Publication
    Distribution of Daphnia resting eggs: Invasive vs native and their effects
    (Oklahoma State University, 2019-04-27) Enders, Kacie
    Daphnia lumholtzi is an example of a successful aquatic invasive species. When conditions are less favorable, D. lumholtzi switch from producing female eggs to the production of diapausing eggs (called ephippia) that are encased in chitinous shells and can form an egg bank in the sediment. Southern reservoirs do not experience extreme seasonal changes in temperature, so D.lumholtzi may rely less on resting eggs for maintaining their populations, because they can survive through most of the year compared to D. lumholtzi populations in northern reservoirs. The purpose of this study was to document the densities of ephippia from D. lumholtzi and native Daphnia in a sediment core collected from Grand Lake, OK. The D. lumholtzi ephippia were dispersed at a relatively constant rate throughout the vertical core. Daphnia lumholtzi did not appear to have a negative effect on the native Daphnia spp. based on the results that the ephippia of native Daphnia were not negatively related to the ephippia of D. lumholtzi. Future efforts should focus on spatial dynamics within reservoirs to determine how egg bank composition differs spatially, as well as, methods for identifying native Daphnia ephippia to the species level.
  • Publication
    Effects of vancomycin and ceftazidime on biofilm formation in Elizabethkingia
    (Oklahoma State University, 2019-04-27) Fritch, Bradley R.; Lanier, Braden M.
    Elizabethkingia infections are associated with high mortality rates which is due in part to the antibiotic resistance expressed by all Gram-negative Elizabethkingia species. Biofilm formation by Elizabethkingia provides the bacteria with further defense against the action of antibiotics. Vancomycin is an unusual drug used to treat Elizabethkingia infections, but its use is controversial, since it is normally only used to treat Gram-positive infections. Our study tests the effect of vancomycin and ceftazidime on biofilm formation for all known species of Elizabethkingia. Biofilm formation was measured at 24, 48, and 72-hour timepoints using a crystal violet biofilm assay. Biofilm formation occurred in all positive control wells for all three timepoints for all species. The biofilms of Elizabethkingia meningoseptica in the presence of subinhibitory vancomycin concentrations, and Elizabethkingia ursingii in the presence of inhibitory ceftazidime concentrations, were reduced compared to the controls. This suggests that both drugs can inhibit biofilm formation in a species-specific manner.
  • Publication
    Examining the role of MekA and YakA in Dictyostelium signaling
    (Oklahoma State University, 2019-04-27) Dreadfulwater, Stormie
    A series of trials were conducted to determine how each protein or kinase plays a role in the signaling of a cell. Among the factors tested were response time, extent of response, and the response under varying stimuli (stimuli included cAMP and folic acid). The primary focus of my individual tests was the role of the kinases mekA and yakA, and I collaborated with my partner to study PakF. Throughout these tests it was shown that yakA- cells respond to either stimuli similar to wild-type cells but mekA- cells show a slower response or no response at all. With these results in mind, MekA was shown to play a possible role in the adaptation of the response, bringing a cell back to its unstimulated state. It is unclear what role YakA plays within a cell, but it does not seem to play a role in this signaling process.
  • Publication
    Effect of idiographic worry on emotional processing
    (Oklahoma State University, 2019-04-27) Watkins, Austin K.
    Emotional processing to internal threat is increasingly being studied as a way to evaluate the effect of worry on attention. The current study seeks to use event related potentials (ERPs), specifically the Late-Positive Potential (LPP), to determine how an idiographic worry episode effects the amount of neural resources individuals use to emotionally process internally produced threat. Participants will engage in thought manipulations intended to provoke either worry or positive emotion towards several daily topics while viewing a cue for each topic. Then the visual cues for each topic will be displayed on a computer screen and an electroencephalogram will be collected to obtain the LPP Potential to assess the amount of emotional processing the participants engage in. We anticipate the worry manipulation group will exhibit higher levels of emotional processing. These results would suggest that worry causes individuals to use more neural resources to emotionally process threat. This increase in threat processing could disrupt the balance between stimulus and goal driven attention systems resulting in impaired attentional control.
  • Publication
    How temperature may affect horses: Using ethograms to examine horse behavior based on variations in weather
    (Oklahoma State University, 2019-04-27) Davidson, Madissen T.
    This study is to serve as a baseline for future research regarding horses. The study was conducted by observing the horse's behavior and characteristics in various weather conditions from a proximal distance of 75 ft (25 yd). A chart of the animal's behavior and characteristics (ethogram) was created as a guide for learning how horses respond to weather. The preliminary results indicate that horses will adapt to their surroundings. When the temperature averages above or below 60 degrees Fahrenheit (15.6 degree Celsius) the horses displayed characteristics of relaxation and comfort.
  • Publication
    Interacting effects of soil microbes and spiders on plant growth
    (Oklahoma State University, 2019-04-27) Smith, Gabriella
    Biotic factors contribute greatly to the success of nutrient cycling, this is done by recycling and translocating nutrients microbe. Research has shown that high densities of predators affect the amount of nutrients deposited into soil and the flow of nutrients within an ecosystem. A recent study has shown that spiders consume 400-800 million tons of food per year, although, for such a large group of predators little is known about the relationship between spiders and nutrient cycling. The goal of this study was to test if the presence of a single spider and the presence of soil microbes plant growth. To do this, we collected soil and female Carolina wolf spiders (Hogna carolinensis) from a local field. Half of the soil was sterilized, while the other half was left natural. Within these two groups of sterile and natural soil, some containers contained a spider while others were left empty to act as controls. After feeding the spiders for 2 months I soil respiration, and plant growth. interaction between spiders and soil microbes plant mass, plant height, and the number of flowers produced.
  • Publication
    Client depletion assay comparison of paclitaxel to Hsp90 inhibitors
    (Oklahoma State University, 2019-04-27) Wagner, Lori; Cartmell, Taylor; Jurczak, Joanna; Kiel, Klaudia
    Many researchers have claimed they have found a successful inhibitor of Hsp90; however, we suspect they are only successful when the inhibitor is used in large quantities. On top of being one of the easiest ways to show an effective inhibitor, researchers are claiming they have found an inhibitor when only meeting as few as two hallmarks. Due to the researchers' inhibitors only meeting two of the criteria, we are trying to show whether these limited expectations are a valid way in identifying Hsp90 inhibitors. We think the client depletion assay test is not specific to Hsp90 inhibitors but instead is a generalized cell response to cell death. At this point in our research, we know a lot about client depletion assays and Hsp90s; however, we do not know if the claims these researchers are making are valid claims because of the amount of Hsp90 inhibitor they are using.
  • Publication
    How can the measurement of fluorescence help with Eastern Red Cedar disaster?
    (Oklahoma State University, 2019-04-27) Roopnarinesingh, Christian
    Juniperus virginiana, more commonly known as the Eastern Red Cedar, has caused excess economic damage due to its dynamic flammability in the Great Plains. Research on the variables in which Eastern Red Cedars are flammable have been proven useful in combating these tragic events. Recording live fuel moisture (LFM) and water potential are accurate when a researcher wants to know the flammability of the plant. However, fluorescence can be used as a more convenient way of measuring water potential, and therefore flammability due to its user-friendly and less costly fluorometer instrument.
  • Publication
    Effect of microhabitat and body size on toe pad size in arboreal, semi-arboreal, and torrential frogs
    (Oklahoma State University, 2019-04-27) Butefish, Alexis
    Frogs can be classified into specialized microhabitats, and for our study, we chose to focus on arboreal (tree dwelling), semi-arboreal (tree and terrestrial dwelling), and torrential (freshwater stream dwelling) species. These species are characterized by their ability to adhere to substrates in their environments, and the adaptations that support these adhesive abilities are enlarged finger and toe pads on the distal tips of each digit and specialized ventral epithelia. A distinction between arboreal and torrential species is that arboreal and semi-arboreal species rely on finger/toe pads alone to adhere, whereas torrential species utilize pads and ventral surfaces. Previous studies have focused on the relationship between morphology and adhesive efficiency, but we sought to analyze the influence of microhabitat and body size on finger/toe pad size. We hypothesized that arboreal species would have the greatest toe pad size in relation to a given body size, followed by torrential and then semi-arboreal with the smallest toe pad area. We measured the body size and toe pad area of 230 specimens, and our results supported our hypothesis. We found that microhabitat and body size have a significant effect on toe pad size.
  • Publication
    Beta-lactamases in the multidrug resistance opportunistic bacterial pathogen Elizabethkingia anophelis
    (Oklahoma State University, 2019-04-27) Perdue, Sidney; Tolliver, Hunter
    Beta-lactamases are bacterial enzymes that pose a serious threat within the healthcare field due to their antibiotic resistance towards commonly prescribed antibiotics, including penicillins, cephalosporins, and cephamycins. Elizabethkingia anophelis, originally discovered from the Anopheles mosquito gut, is the most healthcare relevant species of Elizabethkingia due to the severity of the diseases it causes in humans, including meningitis and respiratory infections in populations with weakened immune systems. The work presented here is the beginning stages of identifying unknown beta-lactamases within E. anophelis. In this study, we have examined the genome of E. anophelis R26 and found 3 known beta-lactamases and 17 additional putative beta-lactamases that we will use for further identification testing. In addition, we have started the cloning process with the native promoter in each of the putative beta-lactamases.
  • Publication
    DNA barcoding for identifying zooplankton
    (Oklahoma State University, 2019-04-27) Phelps, Braylen
    DNA barcoding is still a relatively new field of study that is gaining popularity as it becomes more available. But there is no single protocol that works consistently and efficiently. While there are protocols that have been developed and proven to be successful, they are for specific organisms. In this article, I took the approach of focusing on a zooplankton species, Daphnia magna, to develop a protocol that worked consistently for DNA barcoding freshwater zooplankton. A series of experiments was run to optimize each step of DNA barcoding until a control protocol was developed that could be applied to other species of zooplankton. I expect the final optimized protocol to be robust and capable of being applied to different organisms.
  • Publication
    Single step polyfluoroarylation of amides
    (Oklahoma State University, 2019-04-27) Noel, Alyssa; Hamilton, Matthew; Jesperson, Daniel; Keen, Brockton
    Per- and polyfluoroarenes are important synthetic chemistry targets because they are active components in many pharmaceuticals, agrichemicals, and industrial manufacturing products. Many of the current methods of synthesizing these fluoroarenes involves selectively adding fluorines one at a time. These procedures are rudimentary and often demand long and harsh reaction conditions and often result in poor yields. Novel substrates can be reached, however, through selective hydrodefluorination or functionalization, i.e. fluorine sculpting. This research compliments recently developed chemistry which synthesizes starting material fluoroarenes in two steps by shortening the synthesis by 50%. This chemistry utilizes nucleophilic aromatic substitution to synthesize per- and poly-fluoroaryl amides in a single step under mild reaction conditions which can then be utilized for fluorine sculpting.
  • Publication
    Cellular senescence in cultured human brainstem astrocytes: Effect of oxidative stress
    (Oklahoma State University, 2019-04-27) Leibhart, Zane
    Cardiovascular diseases are one of the leading causes of mortality in the elderly. A central role in the contraction of cardiovascular diseases by means of aging could be played by cellular senescence. Senescent cells accumulate with age in various tissues of the body including the brain. Recent studies from our lab have shown that there is increased senescent cell accumulation in the brainstem in aged mice. Neurons in the brainstem is responsible for the control of sympathetic nerve activity to several vascular beds and overactivity of the sympathetic neurons would lead to increased risk for cardiovascular diseases. It is well documented that neurons are post mitotic and do not undergo senescence, however glial cells could undergo senescence and have implications in neuronal function. In this study we developed a cell culture model to study senescence in vitro. We have used cultured human astrocytes and subjected them to oxidative stress by means of hydrogen peroxide treatment. We believe that increasing levels of hydrogen peroxide will lead to an increase in the number of senescent cells present within the cultured human brain stem astrocytes. Our results showed that there are increased levels of senescence marker p16 and senescence associated secretory phenotype IL6 upregulated after hydrogen peroxide treatment along with decreased levels of laminB1. These results suggest that we were able to induce senescence in human brainstem astrocytes and it could be used as a suitable model to study senescence in vitro. We were able to establish a model using human cells, replicating the cellular senescence in the mice and our future goal would involve understanding the mechanism by which senescence cells in the brainstem would affect the sympathetic regulation.
  • Publication
    Determining the role of Gɑ3, Gɑ8, and PakF in Dictyostelium signaling
    (Oklahoma State University, 2019-04-27) Kiger, Nicholas
    Dictyostelium discoideum is a free-living amoeba found in the soil. Dictyostelium (commonly referred to as "slime mold") exists as a unicellular amoeba in optimal environmental conditions. In suboptimal conditions (specifically when food is scarce) Dictyostelium does something that many other amoebas cannot. Individual Dictyostelium cells release chemicals into the environment, signaling nearby cells to converge into a multicellular aggregate. This allows for the formation of spores until nutrients again become readily available. Dictyostelium can be useful as a model organism for studying the various pathways through which chemotaxis, the movement of cells in response to a chemical in the cell's environment, takes place. Many of the cell signaling pathways through which chemotaxis occurs in Dictyostelium are similar to those in mammalian cells, specifically human white blood cells (leukocytes). Not only is Dictyostelium simpler and less difficult to culture than leukocytes, it is haploid, which makes mutations in target genes easier to perform than in diploid human cells. For these reasons, Dictyostelium is a useful model organism to understand the cell signaling pathway when stimulated with chemoattractants, and results gained will help provide insights into the cell signaling pathway in other cells, specifically the immune cells of humans.
  • Publication
    Feeding behavior of Acheta domesticus infected with Paragordius varius
    (Oklahoma State University, 2019-04-27) Lagarde, Bailey; Dixon, Kierra; Henneha, Beau
    There has not been a lot of research on the phylum nematomorpha, hairworms. There is a large gap in the knowledge of hairworms in their host-parasite relationship, especially on their dietary habits. Our study observed the food consumption of house crickets (Acheta domesticus) by hairworms (Paragordius varius). We recorded the mass of the amount of food consumed by the crickets every five days. Our study did not identify a difference between crickets exposed to hairworms and those not exposed but this may be due to unexpected deaths of the crickets and a small sample size of infected crickets further research needs to be conducted to determine if the food consumption of crickets infected with hairworms differs from uninfected crickets.
  • Publication
    Evaluating the core microbiome of Manduca sexta
    (Oklahoma State University, 2019-04-27) Johnson, Macy
    Microbiomes are complex communities of microorganisms that colonize many surfaces of an animal's body, especially those niches lined with carbohydrate-rich mucosal layers such as the eyes, male and female reproductive tracts, and the gastrointestinal tract. While a vast majority of data from microbiome studies has relied almost extensively on metagenomics-based approaches to identify individual species within these small complex communities, the contributions of these communities to host physiology remain poorly understood. We used a combination of culture- and non culture-based approaches to identify and begin functionally characterizing microbial inhabitants stably colonized in the midgut epithelium of the invertebrate model Manduca sexta (tobacco hornworm), an agriculture pest of Nicotiana attenuata (wild-tobacco) and many additional solanaceous plants.