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BIOL2022RUTLEDGE25520 BIOL

Pollen Source and Abundance Effects on Fitness of a Carnivorous Plant

Type: Undergraduate
Author(s): John Rutledge Biology
Advisor(s): John Horner Biology
Location: Basement, Table 5, Position 1, 1:45-3:45

Plants with threatened habitats and fragmented populations may require repatriation efforts to maintain healthy populations. Populations of Sarracenia alata, the pale pitcher plant, are severely fragmented, and the species is near threatened. A complete understanding of its reproduction will be crucial in establishing and maintaining healthy populations. The goals of this study were to determine if 1) S. alata is capable of selfing (reproducing with pollen from the same individual); 2) S. alata is capable of autogamy (selfing without intervention); and 3) pollen load affects reproductive success. We used seed set to measure individual fitness. Thus, it was necessary to determine a reliable method of counting seeds. Two methods were examined, and these gave statistically similar results. We found that while S. alata is capable of selfing, it is not autogamous. Seed set was significantly higher in outcrossed individuals than in selfed individuals . In 2019, plants receiving supplemental pollen yielded more seeds than those in either the control group or a group in which pollinator access was restricted. During 2021 (a year with higher pollinator activity), there was no significant difference between the number of seeds produced by control plants and those receiving supplemental pollen. This study demonstrates the important role of pollinators in maintaining healthy populations in this system.

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BIOL2022SACHDEVA19088 BIOL

There and back again: Using whole genome sequencing to identify the genes associated with migration patterns in rainbow trout

Type: Undergraduate
Author(s): Shriya Sachdeva Biology
Advisor(s): Matt Hale Biology Giridhar Akkaraju Biology Mikaela Stewart Biology Keith Whitworth Biology
Location: Basement, Table 2, Position 2, 11:30-1:30

Migration, which is defined as the seasonal movement for survival or reproductive advantage such as access to resources, is a behavioral phenomenon exhibited by many species including the salmonid Oncorhynchus mykiss. More commonly known as rainbow trout, O. mykiss exists in two life histories: migrants (steelhead trout), and residents (rainbow trout). While there are many factors that contribute to this variation in migration behavior, one of the reasons is their genetic makeup since there is an apparent correlation between the migratory behavior of parents and their offspring. The primary objective of this research project is to identify single nucleotide polymorphisms (SNPs), or genetic differences, which are associated with migratory behavior in rainbow trout. To that end, I used whole genome sequence data from five migrant and five resident rainbow trout. These data were aligned to the trout genome and used to locate genetic differences between the two migratory types. Quantitative PCR (DMAS-qPCR) approaches were used to validate the SNPs and genotype them in a larger set of twenty-five migratory steelhead. Research findings exhibited that Sashin Lake is producing smolts (young migratory steelhead) that are successfully returning to the lake and reproducing at the end of their life cycle. Additionally, while there was not a significant difference seen in terms of marine survival between the sexes, females were more likely to migrate compared to their male counterparts due to the reproductive advantage and greater access to resources that migration offers. This data will support future studies observing trout migratory behavior with larger sample sizes and from different generations and settings and will benefit conservation studies regarding population decline in migratory species.

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BIOL2022SINDELAR15969 BIOL

Determining biochemical and biophysical methods to evaluate the interaction between BRCA1 and estrogen receptor alpha

Type: Undergraduate
Author(s): Molly Sindelar Biology Mikaela Stewart Biology
Advisor(s): Mikaela Stewart Biology
Location: Basement, Table 7, Position 2, 11:30-1:30

BRCA1 is a gene whose protein (also named BRCA1) is found throughout all human cells and engages in DNA repair, cell cycle regulation, gene transcription regulation, and apoptosis. However, mutations in BRCA1 typically confer a higher risk of cancer in estrogen-responsive tissues, including breast epithelial tissue. This increase in incidence of tissue-specific cancers is thought to be in part due to the role of BRCA1 in the estrogen response pathway and interaction with the estrogen receptor alpha (ERα). Previous studies identified possible regions of each protein involved in the binding interface between BRCA1 and ERα. Using these regions (amino acids 177-240 in BRCA1 and the ligand binding domain of ERα) as our constructs, our studies further analyzed the molecular details of this direct interaction and determined methods conducive to studying the BRCA1-ERα interaction. A pull down assay qualitatively confirmed binding between the constructs of BRCA1 and ERα. Data collected from NMR spectroscopy reaffirmed the direct interaction between BRCA1 and ERα first seen in the pull down assay and provided evidence demonstrating that the presence of estrogen in the samples increased binding affinity. Finally, fluorescence spectroscopy of quenching experiments confirmed the previous two results – that a direct interaction between the constructs of BRCA1 and ERα used occurs and the binding affinity increases in the presence of estrogen – and allowed us to describe the binding curve of the system being studied. The molecular details confirmed here provide further avenues of study, such as documenting variants of unknown significance or studying the role estrogen plays in the function of the BRCA1-ERα complex, which could lead to novel findings that expand our understanding of the role either protein plays in cancer development.

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BIOL2022VO2122 BIOL

Antioxidant Therapy: A Potential Treatment for Alzheimer’s Disease & Chronic Inflammation

Type: Undergraduate
Author(s): Margaret Vo Biology Gary Boehm Psychology Paige Braden-Kuhle Psychology Evan Chandlee Psychology Michael Chumley Biology Kayla Green Chemistry & Biochemistry Chelsy Mani Biology Shelby Kay Miller Psychology Caroline O'Connor Biology
Advisor(s): Michael Chumley Biology
Location: Second Floor, Table 1, Position 2, 11:30-1:30

Alzheimer’s disease (AD) affects about 6 million Americans, and hallmark pathologies of AD include amyloid beta (Aβ), inflammation, and oxidative stress. Microglial cells (MGCs) are brain cells that function like immune cells, and they respond to Aβ by secreting pro-inflammatory cytokines. Cytokines induce inflammation at sites of infection, and Aβ continually increases inflammation, resulting in neuronal death. Inflammation is also connected to oxidative stress, and prior research has demonstrated that Nrf2 (a transcription factor) protects cells from oxidative stress by increasing antioxidant enzymes. We will test potential benefits of molecules with antioxidant capabilities, created by Dr. Green (TCU Chemistry), on inflammation and Nrf2 expression in MGCs. Previously, we demonstrated that these compounds, L2 and L4, are powerful antioxidants that protect MGCs from oxidative stress. Currently, we aim to study the effects of L2 and L4 on inflammation, Nrf2 expression and heme oxygenase-1 (antioxidant) production following an inflammatory insult. We will pre-treat MGCs with different concentrations of L2 and L4, and then stimulate MGCs with lipopolysaccharide (LPS), a bacterial mimetic. Subsequently, we will measure pro-inflammatory cytokines, Nrf2 expression and antioxidant response genes. Overall, it is crucial for researchers to investigate effective therapeutics that could relieve AD symptoms, such as antioxidant treatment.

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BIOL2022WIENCEK3133 BIOL

Identifying Alternative Marine Toxicity Testing Methods: Can Mysids and Fish Embryos Replace Larval Fish?

Type: Undergraduate
Author(s): Maddie Wiencek Biology Dalton Allen Biology
Advisor(s): Marlo Jeffries Biology
Location: Second Floor, Table 6, Position 2, 1:45-3:45

Testing of chemicals that enter our waterways is necessary to keep marine environments healthy. The current method of toxicity testing is the larval growth and survival (LGS) test, which exposes larval fish to varying concentrations of an effluent or chemical. Given recent legislation that calls for improvements in the welfare of animals used in toxicity testing, there is a need to identify alternatives to the LGS test. In light of this, the objective of the current study was to determine whether toxicity tests featuring fish embryos or shrimp could be used in place of LGS tests.

To accomplish this, we compared the results of the standard LGS test using inland silverside larvae with the results from two alternative tests, a mysid (e.g., shrimp) test and an inland silverside fish embryo toxicity (FET) test. The results of this study show that both the mysid and FET tests are promising alternative testing methods to the LGS test. The adoption of either test type will meet legislative goals and improve the welfare of fish used in toxicity testing.

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