2020 Abstracts

Hess, Kavan; Herring, Jacob; Yang, Haokun; Tessem, Jeff (Brigham Young University)
Faculty Advisor: Tessem, Jeff (Brigham Young University; Department of Nutrition, Dietetics, and Food Science)

Diabetes is the seventh leading cause of death in the United States, and often accompanies other life-threating complications. There are two main types of diabetes that are both characterized by disfunction or destruction of insulin producing beta cells found in the islets of Langerhans. Islets of Langerhans are composed of endocrine hormone secreting cells, including alpha cells (glucagon), beta cells (insulin) delta cells (somatostatin), epsilon cells (ghrelin) and PP cells (pancreatic polypeptide). While alpha and beta cells make up ~90% of all the cells in the islet, delta cells comprise only ~10% and are responsible for cross talk in the islet. Delta cells regulate intra-islet cross talk through the secretion of somatostatin-14. It has been shown that Nr4a1 and Nr4a3 overexpression induces beta cell proliferation, while Nr4a1 or Nr4a3 deletion inhibits insulin secretion when challenged with glucose. Delta cells contain three times the amount of Nr4a1 mRNA than beta cells. However, no research has been done on the role of either of these transcription factors in the cross talk between the different cell types of the islet. Here we aim to show how a lack of Nr4a1 and Nr4a3 affects delta cell somatostatin release when challenged with glucose.

Leavitt, Amanda; Harris, Heather; Szanter, Kathryn; Stokes, Alexis (Weber State University)
Faculty Advisor: Dunn, Charles (Weber State University, Child and Family Studies); Hubler, Daniel (Weber State University, Child and Family Studies); Osai, Keith (Weber State University, Child and Family Studies)

How a child is parented can influence their success socially, mentally, physically, and emotionally. Agarwal (2017) states that "Parenting plays the most important part in any child's life, it can help a child by teaching them to deal with people, situations and adapt to a better living standard" (p.1335). Parents help form worldviews, shape a child's attitude towards personal achievement, teach how to approach adversity in life, and satisfy their needs whether it be psychological and/or physiological. Much is known about how the base of one's childhood is built upon one's primary caregivers' parenting style, however, less is known about the intergenerational transmission of parenting philosophies.

The current study was designed to assess how parenting styles affect child delinquency and bullying. Through social media invitations and snowball sampling, 200 people accepted invitations to participate in an online survey incorporating both open-ended and quantitative items. Participants were asked to reflect on how they were parented and then state what they have maintained or changed in their own parenting styles. Considering the rich nature of the responses to the qualitative items, a corroborative narrative came together through personal stories.

Through thematic analysis, several themes emerged. When participants reported being parented with: open communication, flexibility, love, trust, and higher expectations they wanted to keep those traits. When asked what participants carried on from their parents one participant stated, "Cherish the family and the moments we have together." Additionally, 28% (n = 113) of our participants shared the importance of spending quality time together. However, when participants' parents did not display those traits, most participants indicated that similar traits, namely communication, flexibility, love, quality time, trust, and higher expectations were desired in their homes. The findings from the current study can be used to inform future parenting research assessing influence on subsequent generations.

Miriam Reber; Ethan Del Toro; Holden Lyman; Weston Hargis; Travis Ficklin (Dixie State University)
Faculty Advisor: Ficklin, Travis (Dixie State University, Health and Human Performance)

In recent years sport climbing has increased in popularity, and with that have come questions regarding what factors improve performance. While multiple studies have examined the effect of anthropometric factors on injury in climbing, few have examined their relationship with climbing performance. Therefore, the purpose of this study is to compare the anthropometric measures of high-level to intermediate level climbers to determine if certain body types, or dimensions, lend themselves to better performance in climbing.

Twenty-one subjects were divided into an intermediate (INT) or high-level (HL) group based on highest graded climb achieved. Various measures including height, limb lengths, and experience. These were compared between the two groups using t-tests.

Significant differences were found in the number of days climbed per week (HL 2.9±1.1, INT 2.17±0.6, p = 0.03), and the ratios of upper arm to full arm length (HL 0.44±0.05, INT 0.41±0.02, p=0.03), and trunk to height (HL 0.26±0.03, INT 0.23±0.01, p=0.01). There were also statistical trends towards years of experience (HL 5.46±3.8, INT 3.39±1.8, p = 0.06), and trunk length (HL 44.96±7.1cm, INT 41.28±2.7cm, p=0.06).

The current data suggest that for the levels of climbing examined (5.9-5.13b on the Yosemite Decimal Scale) a greater trunk to height ratio, greater upper arm to arm length ratio, and increased frequency of practice (a variable within the climber's control) may positively impact climbing ability.

LeBaron, Josh; Obray, J Daniel; Steffensen, Scott (Brigham Young University)
Faculty Advisor: Steffensen, Scott (Family, Home, and Social Sciences, Psychology)

Dopamine neurons in the substancia nigra (SN) and ventral tegmental area (VTA) are inhibited by dopamine (DA) via dopamine 2 receptor (D2R) activation. D2R expression in the striatum is a well-known biomarker for brain DA levels, drug abuse, and dependence. Markers of D2R expression are not only detectable in the brain but are also expressed in peripheral tissues, including the blood, where DA appears to play a pivotal role in mediating communication between the nervous and immune systems. Alteration in lympocytic D2Rs are seen in chronic psychostimulant use (Ersche et al., 2011). For the last two decades it has been generally accepted that D2R expression in the striatum is reduced by chronic ethanol use. Additionally, research has suggested that these changes mirror changes in DA levels in the striatum and predict risk of relapse. Despite this, the timecourse over which these changes occur has not been demonstrated. Further, recent research has challenged both the reduction in D2R expression produced by chronic ethanol and the mechanism whereby it was believed to be produced (reductions in striatal DA levels). This research has suggested that alterations in D2R levels may be due to disruption of sleep in individuals with substance use disorders. Here we demonstrate that dopamine 2 receptor expression in the brain and the blood follows brain and blood dopamine levels on a timescale of minutes to hours following an acute dose of ethanol. This research provides evidence for transient changes in D2R expression following a single dose of ethanol.

Tonks, Adam; Domgaard, Hannah; Crowley, Valerie; Neumann, Gina; Keiser, Dylan; Metcalf, Josie; Guo, Hongjie; Zhou, Yi; Begemann, Mathew; Taylor, David; Jackson, Ryan (Utah State University)
Faculty Advisor: Jackson, Ryan (College of Science, Chemistry and Biochemistry)

Cms1 is a Type V endonuclease that contains a novel domain, shares little sequence homology with other Type V endonucleases, and in some organisms, is found near genes coding for other single-subunit nucleases. Studies in rice (Oryza sativa) have shown Cms1 capable of RNA-directed DNA editing. However, the mechanism of DNA cleavage remains unknown.
Here we present biochemical data that demonstrate Cms1 from Sulfuricurvum processes an RNA guide and binds/cleaves single- and double-stranded DNA through RuvC nuclease motifs. 2-D classification of structures obtained by negative staining electron microscopy show a major conformational change between SuCms1 bound and unbound to an RNA guide. The predicted global structure appears to be different than those reported for other Type V effectors. These data provide for a greater understanding of Type V endonucleases and may provide an alternative tool for genome editing applications.

Hutchison, Cortland; Preece, J. Caleb; Seibold, Tanner; Feland, J. Brent (Brigham Young University)
Faculty Advisor: Feland, Brent (Life Sciences, Exercise Science)

BACKGROUND: Muscle morphology changes with age and the fibrous/fatty infiltration should affect the overall stiffness of aging muscle. However, little info intrinsic stiffness as measured by SWE is available on aging muscle and the effect of gender using this measurement is not clear.
PURPOSE: This study aimed to determine how gender affects cross sectional area (CSA) and SWE of both the medial and lateral heads of the gastrocnemius muscle of the dominant leg in active older athletes participating in the HuntsmanWorld Senior Games.
METHODS: Data was collected from 116 volunteers (participants in the Huntsman World Senior Games) in St. George, Utah, 2019. Subjects (62 males: mean age = 68.9 ± 7.8 yrs, Ht = 177.4 ± 8.1 cm, Wt= 85.4±20 kg; 54 females: mean age = 66.9 ± 8.5 yrs, Ht =164.4 ± 7.2 cm, Wt= 69.8±18 kg) signed an approved consent form and then lay prone on a treatment table for ultrasonic measurement of both CSA and SWE of both heads of the gastrocnemius.
ANALYSIS: All data were analyzed a generalized linear model analysis using SPSS ver25 comparing CSA and SWE of both medial and lateral gastrocnemius heads by gender with age, height and weight as covariates.
RESULTS & CONCLUSION: We hypothesized that gender would affect both CSA and SWE with males exhibiting increases in both CSA and SWE values. We found a significant difference in CSA of both the medial and lateral gastroc (p=.000 for both) between genders, but no significant difference in lateral gastroc SWE (p=.337) or medial gastroc SWE (p=.320). Both age (p=.004) and weight (p=.000) were also found to significantly affect CSA and SWE between genders. The larger CSA values for men in this study may be more of a function of overall body size and weight since both populations are active athletes.

Tessem, Jeffery; Lloyd, Trevor; Brown, Nathan (Brigham Young University)
Faculty Advisor: Tessem, Jeffery (Brigham Young University; Nutrition, Dietetics and Food Science)

Diabetes is a global epidemic affecting millions of people. The total estimated cost of diabetes in the U.S. during 2017 was 327 billion dollars [1]. Diabetes is characterized by the loss of pancreatic β-cell function which is caused by an autoimmune disorder in Type 1 diabetes or insulin resistance and β-cell exhaustion in Type 2 (T2D) diabetes. Lifestyle changes in diet are beneficial in treating T2D. Phytochemicals are commonly utilized in these diets, and recent studies show diets high in flavanols exert beneficial bioactivity for β-cells. While flavanols demonstrate beneficial effects on β-cells, these flavanols are rarely observed in circulation, suggesting a necessary intermediate step. Flavanols are metabolized by gut bacteria to smaller metabolites that are absorbable. We hypothesize that these gut bacteria derived flavanol metabolites cross the gut and affect β-cell function. We have fed rats catechin supplemented or unsupplemented diets and collected urine as a means to isolate all absorbable gut flavanol metabolites. Here we present the effects of these absorbed metabolites on β-cell proliferation. This study begins to explain the mechanism by which flavanols exert their beneficial effect on glucose metabolism through the β-cell.

Rollins, Jay; Whitney, Jordan; Hope, Sandra; Mizrachi, Dario (Brigham Young University)
Faculty Advisor: Mizrachi, Dario (Brigham Young University, Physiology and Developmental Biology)

Epithelial and endothelial tissues form selectively permeable barriers, with the permeability largely controlled by intercellular tight junctions. Claudin (CLDN) proteins are critical components of these tight junctions, making them the gatekeepers that control the paracellular space in multicellular organisms. CLDN proteins are thus targets for studies on epithelial and endothelial absorption, to therefore learn how to regulate them for potential drug delivery or therapeutics. CLDN characterization is still in progress. Previously, the relative strength of each member of the CLDN family was unknown. Additionally, no high-throughput method to study absorption enhancers or inhibitors had been found.
Through CLDN expression in Escherichia coli, we determined the relative strength of each CLDN protein and confirmed the effects of various absorption enhancers from previous studies. Therefore, we propose that CLDN expression in Escherichia coli is a valid model for the study of tight junctions and that, through flow cytometry, it is a high-throughput method for interrogating large libraries of potential drug delivery compounds. Using CLDN 2 because of its role in cancer-metastasis prevention and its measured sensitivity towards epithelial modulators, we studied a fifty thousand compound library (DIVERSet-CL Library) to identify absorption moderators, drug delivery compounds, and possible cancer-metastasis prevention.

Beales, Joseph; Lloyd, Trevor; Krueger, Emily; Barlow, Andrew (Brigham Young University)
Faculty Advisor: Tessem, Jeffery (Life Sciences; Nutritional, Dietetics, and Food Science)

Worldwide, an estimated 415 million people suffer from diabetes.1 Diabetes is characterized by chronic dysfunction of the pancreatic ß-cell, which leads to unregulated insulin secretion and abnormal blood glucose levels. Therefore, methods which increase the number of ß-cells or improve their function have potential for complementary treatment of type 2 diabetes. Compounds such as antioxidants and their gut metabolites have received attention in literature as having potential ß-cell-regulating properties.2,3 Therefore, we hypothesize that supplementation of grape seed extract (GSE), which is rich in antioxidants, will enhance ß-cell proliferation and insulin secretion. Accordingly, we obtained metabolites, derived from rats on either a control or grape seed extract diet, to measure the metabolites' impact on ß-cell function through in vitro assays such as glucose stimulated insulin secretion (GSIS) and 3H-thymidine incorporation. Discoveries regarding GSE metabolites' effects on ß-cell function could be fundamental to understanding ß-cell regulation and potential pharmaceutical or dietary treatments for diabetes.

1 Ogurtsova, K., et al. "IDF Diabetes Atlas: Global Estimates for the Prevalence of Diabetes for 2015 and 2040." Diabetes Research and Clinical Practice, Elsevier, 31 Mar. 2017, www.sciencedirect.com/science/article/pii/S0168822717303753?via%3Dihub.

2 Bajaj, Sarita, and Afreen Khan. "Antioxidants and diabetes." Indian journal of endocrinology and metabolism vol. 16,Suppl 2 (2012): S267-71. Doi:10.4103/2230-8210.104057

3 Tsuda, Takanori. "Recent Progress in Anti-Obesity and Anti-Diabetes Effect of Berries." MDPI, Multidisciplinary Digital Publishing Institute, 6 Apr. 2016, www.mdpi.com/2076-3921/5/2/13.

Walker, Carson; Burke, Tyler; Tanner, Call; Chaston, John (Brigham Young University)
Faculty Advisor: Chaston, John (Brigham Young University, Plant and Wildlife Sciences)

Host-microbe interactions can dramatically influence Drosophila melanogaster phenotypes, but few studies have explained how these microbes are recognized by the host. For example, fruit flies from one area, Maine, prefer to consume diets inoculated with Lactic Acid Bacteria (LABs) over diets containing Acetic acid bacteria (AABs); whereas flies from another area, Florida, show no preference for either LAB or AAB. However, the bacterial mechanisms responsible for this preference are unknown. My follow-up analyses further suggest the hypothesis that Maine flies avoid AAB, rather than are attracted to LAB. Therefore, I propose a forward genetic approach to define the AAB processes that shape this fly preference. I will do this by comparing the feeding preferences of Maine and Florida flies to diets incorporated with LAB versus specific bacterial molecules, such as acetic acid, peptidoglycan, and lipopolysaccharides. Alternatively, if these molecules do not mediate the effects I will perform a metagenome wide association assay (MGWA) to identify genes linked to this preference. Together, these approaches will help to reveal the bacterial factors that influence fly feeding preferences.

Desdames, Chloe; Smith, Mick (Salt Lake Community College)
Faculty Advisor: Seaboch, Melissa (Salt Lake Community College, Anthropology)

Spider monkeys (genus Ateles) is one of the many endangered species in Costa Rica and they can now only be found in very few places due to deforestation. It is important for conservation reasons to know what forest types spider monkeys prefer. According to prior research in Surinam, Mexico, and Bolivia, Ateles prefers primary forests (undisturbed, high canopy) over secondary forests (degraded, lower canopy). Ateles are frugivores and their habitat preference depends highly on fruit availability. Fruit is more abundant in primary over secondary forests. This goal of this study was to determine whether spider monkeys in Costa Rica have a similar habitat preference. I hypothesize that spider monkeys will be found more often in high canopy primary forests compared to secondary forests. This research was conducted at La Selva Biological Station in northeastern Costa Rica. La Selva is a protected lowland tropical rainforest consisting of both primary forest (55%) and secondary forest in various stages of regeneration. I conducted a census of Ateles geoffroyi by walking established trails, with markers every 50 meters, in May 2019. Whenever a spider monkey was spotted, the trail name, nearest meter marker, and forest type were recorded. On a census of 9 trails, five Ateles groups were located, with four of the sightings being in primary forests. My hypothesis, that Ateles geoffroyi would be found in primary over secondary forests, was supported because 80% of the sightings were in primary forests. This is especially significant because, of the 20.5 kilometers censused, only 4.6 km censused (22%) were in primary forests with the remaining 15.9 km (78%) in secondary forests. This preference for primary forests agrees with prior studies on Ateles in other Neotropical forests. This highlights the importance of conserving primary forest for the well-being of spider monkeys.

MacLachlan, Aileen; Berges, Bradford (Brigham Young University)
Faculty Advisor: Berges, Bradford (Life Sciences, Microbiology and Molecular Biology)

Staphylococcus Aureus (SA) is a well-known human pathogen causing infection in hospital settings world-wide. Given that SA is becoming increasingly resistant to antibiotics, the need to discover alternative treatments is urgent. One path that SA uses to combat antibiotics is by forming biofilms. Biofilms are microbial cell communities that form on surfaces and employ a complex extracellular polysaccharide matrix to protect the bacteria. In the past, bacteriophage (phage) has been investigated as a potential alternative to treat methicillin-resistant SA (MRSA) and break down its biofilm. Recently, students from Dr. Berges' laboratory isolated 6 novel strains of phage. In a recently published paper from Dr. Berges' lab, these phages demonstrated significant reduction of planktonic strains of SA and MRSA.

In this project, we further explore the ability of these 6 phages in breaking down biofilms from hospital associated SA strains. We plan to measure the reduction of SA biofilms caused by these novel phages against a control. The reduction results will be analyzed with previous research results to detect the presence of a polysaccharide degrading enzyme for the purpose of future research. In addition, we also plan on measuring the ability of the phage in preventing biofilm formation.

Bursell, Madeline; Dikow, Rebecca; Johnson, Warren; Koepfli, Klaus-Peter; Frandsen, Paul (Brigham Young University)
Faculty Advisor: Frandsen, Paul (Life Sciences, Plant and Wildlife Sciences)

Due to decreasing costs in genome sequencing, conservation genomics is a field that has experienced immense growth over the last few years. By comparing whole genome data within threatened and endangered populations, we can estimate important elements in conservation such as levels of homozygosity and demographic histories that reveal the level of endangerment of a species. This information informs conservation priorities and captive breeding programs. In the present study, we focus on two species of clouded leopards: Neofelis nebulosa and Neofelis diardi. N. nebulosa is a species of clouded leopard that lives in mainland southeast Asia. N.diardi inhabits the islands of Sumatra and Borneo in Indonesia. While these two species were initially thought to be a single species, evidence, such as differences in fur color and sizes of cloud markings, hint that they have diverged into two species. To shed more light on the genomic differences between them, we sequenced, assembled, and annotated whole genomes from both species. With genomes, we will explore differences in demographic histories, variation in blocks of homozygosity, and generate a whole genome phylogeny with other large cat species. Using these analyses, we share insights that will inform the conservation status of the two species.

Allen, Sierra; Meyer-Ficca, Mirella; Wandersee, Miles (Utah State University)
Faculty Advisor: Meyer-Ficca, Mirella (College of Agriculture and Applied Sciences; Animal, Dairy, and Veterinary Sciences Department)

Niacin, a component of vitamin B3, is necessary for the synthesis of nicotinamide adenine dinucleotide (NAD+). NAD+ is an essential coenzyme in several metabolic processes, including those that regulate glucose and fat homeostasis in the body. Niacin is available to humans in its dietary form through foods such as meat, various legumes, nuts and vegetables. Niacin deficiency has been linked to health problems including age-related decline of cognitive abilities, as seen in Alzheimer's disease, and impaired dermal repair. In cases of extreme niacin deficiency, individuals may even develop pellagra, a disease characterized by dermatitis, diarrhea and dementia. Recent studies in niacin deficient mice indicate that niacin deficiency impairs proper glucose metabolism. Compared to mice with adequate niacin levels, niacin deficient mice experience a significant loss of total body weight and body fat and have impaired glucose regulation in response to insulin. We hypothesize that these metabolic defects result from inadequate levels of NAD+ preventing the conversion of lactate to pyruvate in the gluconeogenesis pathway, which in turn results in decreased blood glucose levels. Another potential explanation is that niacin deficiency results in decreased glycogen stores in the liver, also impeding glucose production. To test these hypotheses, we are studying the relationship between dietary niacin and glucose metabolism in a transgenic mouse model with acquired niacin dependency that accurately represents human niacin metabolism. Results of this study will contribute to better understanding of niacin's role in proper glucose metabolism, with important implications for diabetes and other glucose-related diseases, particularly in populations with limited access to quality food.

Bonnie K. Baxter (Westminster College)
Faculty Advisor: Baxter, Bonnie (Westminster College, Biology)

Gypsum is a calcium sulfate mineral in a hydrated form. NASA's Mars Exploration Rover, Opportunity, found veins of gypsum deposited by water in 2011(Figure 7), and gypsum has been detected on Mars as early as 2005 by the ESA's Mars Express Orbiter. On Earth, gypsum is formed in hypersaline environments, in minerals left behind when water evaporates and it can trap microorganisms in fluid inclusions. Gypsum obtained from Great Salt Lake was used to develop a method to extract halophilic archaea and culture it in the lab. Our studies show that the mineral was difficult to dissolve in aqueous microbiological media. We tested various methods of dissolution involving mechanical crushing and tested solvents including microbiological media. We also employed a variety of cultivation methods. We will present data on best practices for obtaining halophilic microorganisms from gypsum samples. The method obtained could be used to isolate potential microorganisms present in gypsum samples from Mars.

Sirrine, Michael; Grose, Julianne (Brigham Young University)
Faculty Advisor: Grose, Julianne (Brigham Young University, Microbiology and Molecular Biology)

PAS kinase is a serine/threonine protein kinase known to regulate the pivotal switch between cellular respiration and lipid biosynthesis. One substrate of PAS kinase is Cbf1, a known transcription factor which regulates lipid biosynthesis in yeast and mammalian cells (human homolog USF1). USF1 is associated with hyperlipidemia and hypercholesterolemia in several GWAS studies. We have recently identified and characterized a role for Cbf1 in the regulation of respiration as well, making it a key player in partitioning cellular resources towards respiration versus lipid metabolism. The goal of this proposal is to use the powerful tools of yeast genetics to identify physical interactors of Cbf1 in order to characterize the molecular mechanisms of its action.

Lemmon, Skyler; Chaston, John (Brigham Young University)
Faculty Advisor: Chaston, John (Life Sciences, Plant and Wildlife Sciences)

Over the course of the last year, I have dedicated most of my time in the lab to learning about CRISPR/Cas9 and practicing the laboratory techniques that are necessary to make genetic changes in Drosophila melanogaster. Here I aim to expand on that expertise by applying CRISPR to study a genetic question: how the microbial composition of the D. melanogaster microbiome is affected by the modification of 4 specifically selected genes in flies from Florida and Maine. For each of the selected genes, the Florida fly allele will be put into the Maine fly genome and the Maine fly allele will be put into the Florida fly genome. The microbiome composition of these two new flies will be compared against the original lines in a factorial design. Embryos will be injected with the necessary plasmids for a double-stranded cut to take place. After injection, homology dependent repair that will incorporate the new allele. Sanger sequencing will be used to screen for successful knock-in of the allele. Finally, the concentrations of each type of bacteria found in the microbiota of the flies will be measured and compared against the flies from which the allele came from.

Marchant, Nathan; Marchant Erik; Elison, Weston; Herring, Jacob; Yang, Haokun; Tessem, Jeffrey; Hancock, Chad (Brigham Young University)
Faculty Advisor: Hancock, Chad (Brigham Young University; Nutrition, Dietetics, and Food Science); Tessem, Jeffrey (Brigham Young University; Nutrition, Dietetics, and Food Science)

Purpose: To analyze the effect of the Nr4a3 gene on respiratory capacity of mitochondria in skeletal muscle of mice on a normal or high fat diet.

Methods: Nr4a3-/- and WT mice were fed a normal chow (NC) or high fat diet (HF) for at least 20 weeks. After euthanasia, soleus muscle was harvested and wet weight was measured and prepared for respirometry. Mitochondrial respiration was evaluated using an Oroboros Oxygraph Respirometer. Respiratory capacity comparisons were made with a two-way ANOVA and Tukey multiple comparison test.

Results: Oxygen consumption is reported as pmol/(s*mg wet tissue) and statistics are represented as mean ± SEM. In the WT male mice there was a decrease in coupled complex I supported respiration in HF vs. NC diet (25.9 ± 7.3 vs. 64.5 ± 5.0, p=0.004). In the HF WT group there was also a decrease in uncoupled respiration (61.4 ± 15.0 vs. 107.8 ± 7.1, p=0.0004) compared to NC WT. In female mice there was also a decrease between HF WT and NC WT in complex I (28.2 ± 3.7 vs. 57.4 ± 5.7, p=0.0005) and uncoupled respiration (87.1 ± 7.1 vs. 119.4 ± 8.9, p=0.0001). However, there was no significant difference between the WT NC mice and either of the Nr4a3-/- groups. Coupled complex I and uncoupled respiration states in both Nr4a3-/- groups were not significantly different from WT.

Conclusion: Feeding mice a high fat diet impairs proper mitochondrial function in muscle when compared to a normal chow diet. The decrease in respiration from the HF diet is dependent upon the function of the Nr4a3 gene, as no decrease was observed in Nr4a3-/- mice.