Matching Items (85)
Description
High fiber diets have been associated with improved cardiometabolic health with specific efforts to lower circulating levels of low-density lipoprotein (LDL cholesterol). Whole grain and grain-based foods are major contributors of dietary fiber in the American diet, of which wheat has been extensively studied. Corn, however, has not been well studied for its cholesterol-lowering properties. Further, the mechanisms by which grains improve cardiometabolic health require further exploration with regard to the human microbiome. The objective of this single-blind randomized controlled, crossover trial was to assess the impact of three different corn flours (whole grain, refined, and bran-enhanced refined flour mixture) on serum LDL cholesterol and the gut microbiota diversity and composition. Twenty-three participants were recruited, between the ages of 18-70 with hypercholesterolemia (Male = 10, Female = 13, LDL >120 mg/dL) who were not taking any cholesterol-lowering medications. Participants consumed each flour mixture for 4 weeks prepared as muffins and pita breads. At the beginning and end of each 4-week period serum for cholesterol assessment, anthropometrics, and stool samples were obtained. Serum cholesterol was assessed using a clinical analyzer. Stool samples were processed, and microbial DNA extracted and sequenced based on the 16S rRNA gene. A generalized linear model demonstrated a significant treatment effect (p=0.016) on LDL cholesterol and explained a majority of the variance (R-squared= 0.89). Post hoc tests revealed bran-enhanced refined flour had a significant effect on cholesterol in comparison to whole grain flour (p=0.001). No statistically significant differences were observed for gut microbial community composition (Jaccard and weighted Unifrac) after corn consumption. However, relative abundance analysis (LEfSE) identified Mycobacterium celatum (p=0.048 FDR=0.975) as a potential marker of post-corn consumption with this microbe being differentially less abundant following bran-enhanced flour treatment. These data suggest that corn flour consumption may be beneficial for individuals with hypercholesterolemia but the role of gut microbiota in this relationship requires further exploration, especially given the small sample size. Further research and analysis of a fully powered cohort is needed to more accurately describe the associations and potential mechanisms of corn-derived dietary fiber on circulating LDL cholesterol and the gut microbiota.
ContributorsWilson, Shannon L (Author) / Whisner, Corrie M (Thesis advisor) / Sears, Dorothy (Committee member) / Buman, Matthew (Committee member) / Dickinson, Jared (Committee member) / Zhu, Qiyun (Committee member) / Arizona State University (Publisher)
Created2022
Description
Bats are a highly diverse mammal species with a dense virome and fascinating immune system. The following project utilizes metagenomics in order to identify DNA viruses present in populations of silver-haired bats and Mexican free-tailed bats from southern Arizona. A significant number of DNA viruses and novel viruses were identified in the Cressdnaviricota phylum and Microvirdae family.
ContributorsHarding, Ciara (Author) / Varsani, Arvind (Thesis director) / Dolby, Greer (Committee member) / Kraberger, Simona (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Watts College of Public Service & Community Solut (Contributor)
Created2022-05
Description
Wild horses have roamed the Salt River in Mesa, Arizona since the early 1800s and contribute to the great diversity of the region. Conservation of the herd has been a primary focus for many years and a current focus is population stabilization, but little is known about their virome. Circoviridae, Genomoviridae, and Smacoviridae are the three Cressdnaviricota viruses that have been identified in horses to date. Smacoviridae is classified by the rolling circle replication-associated proteins (Rep) and has a small (2.3-2.9kb), circular, single-stranded genome. The goal of this study was to identify DNA viruses within the fecal samples of the Salt River horses. Samples were collected along the lower Salt River and analyzed in the lab using a metagenomics approach. There were 422 full novel genomes of smacoviruses detected across all samples that were grouped into 144 species based on the similarity of the pairwise identity. Phylogenetic analysis shows the smacoviruses from this study fall into 3 classified genera and the rest cluster into 11 new clades. These results expand the viral diversity associated with wild horses and Smacoviridae, and further studies are needed to determine the host of these viruses.
ContributorsMcGraw, Hannah (Author) / Varsani, Arvind (Thesis director) / Murphree, Julie (Committee member) / Kraberger, Simona (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2024-05
Description
Scorpions are predatory arachnids that are among the most ancient terrestrial invertebrates. They are typically found residing in desert and riparian environments. Viruses associated with scorpions have been explored in the past, unveiling partial RNA virus sequences and polyomaviruses, but more research in this area is necessary. Cycloviruses are non-enveloped viruses with circular single-stranded DNA genomes (~1.7 to 1.9 kb). Cycloviruses were initially identified in mammals and have now been detected in samples from a wide range of mammalian and insect species. Polyomaviruses are double-stranded DNA viruses (~4 to 7 kb). They are known for causing tumors in the host it infects, and have previously been identified in a diverse array of organisms, including scorpions. The objective for this study was to identify known and novel viruses in scorpions. Using high-throughput sequencing and traditional molecular techniques we determine the genome sequences of cycloviruses and polyomaviruses. Sixteen of the forty-three scorpion samples were positive for eight different species of cycloviruses. According to ICTV guidelines, seven of the eight species were novel cycloviruses which were found in bark scorpions, stripe-tailed scorpions, yellow ground scorpions, and giant hairy scorpions (Centruroides sculpturatus, Paravaejovis spinigerus, Paravaejovis confusus & Hadrurus arizonensis) from Maricopa, Pinal, and Pima county in Arizona, USA. Additionally, one previously known cyclovirus species was recovered in bark scorpions (Centruroides sculpturatus) in Pima county which had previously been documented in guano from a Mexican free-tailed bat in Arizona. There were ten scorpions out of forty-three for which we recovered polyomavirus scorpion samples that grouped into four different polyomavirus species. Polyomaviruses were only identified in bark scorpions (Centruroides sculpturatus) from Maricopa, Pinal, and Pima county. Of the polyomavirus genomes recovered three belong to previously identified scorpion polyomavirus 1 and five to scorpion polyomavirus 3, and two represent two new species named scorpion polyomavirus 4 and scorpion polyomavirus 5. The implications of the discovery of cycloviruses and polyomaviruses from this study contributes to our understanding of viral diversity associated with Scorpions.
ContributorsGomez, Magali (Author) / Neil, Julia (Co-author) / Varsani, Arvind (Thesis director) / Kraberger, Simona (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / School of Life Sciences (Contributor)
Created2024-05
Description
Scorpions are predatory arachnids that are among the most ancient terrestrial invertebrates. They are typically found residing in desert and riparian environments. Viruses associated with scorpions have been explored in the past, unveiling partial RNA virus sequences and polyomaviruses, but more research in this area is necessary. Cycloviruses are non-enveloped viruses with circular single-stranded DNA genomes (~1.7 to 1.9 kb). Cycloviruses were initially identified in mammals and have now been detected in samples from a wide range of mammalian and insect species. Polyomaviruses are double-stranded DNA viruses (~4 to 7 kb). They are known for causing tumors in the host it infects, and have previously been identified in a diverse array of organisms, including scorpions. The objective for this study was to identify known and novel viruses in scorpions. Using high-throughput sequencing and traditional molecular techniques we determine the genome sequences of cycloviruses and polyomaviruses. Sixteen of the forty-three scorpion samples were positive for eight different species of cycloviruses. According to ICTV guidelines, seven of the eight species were novel cycloviruses which were found in bark scorpions, stripe-tailed scorpions, yellow ground scorpions, and giant hairy scorpions (Centruroides sculpturatus, Paravaejovis spinigerus, Paravaejovis confusus & Hadrurus arizonensis) from Maricopa, Pinal, and Pima county in Arizona, USA. Additionally, one previously known cyclovirus species was recovered in bark scorpions (Centruroides sculpturatus) in Pima county which had previously been documented in guano from a Mexican free-tailed bat in Arizona. There were ten scorpions out of forty-three for which we recovered polyomavirus scorpion samples that grouped into four different polyomavirus species. Polyomaviruses were only identified in bark scorpions (Centruroides sculpturatus) from Maricopa, Pinal, and Pima county. Of the polyomavirus genomes recovered three belong to previously identified scorpion polyomavirus 1 and five to scorpion polyomavirus 3, and two represent two new species named scorpion polyomavirus 4 and scorpion polyomavirus 5. The implications of the discovery of cycloviruses and polyomaviruses from this study contributes to our understanding of viral diversity associated with Scorpions.
ContributorsNeil, Julia (Author) / Gomez, Magali (Co-author) / Varsani, Arvind (Thesis director) / Kraberger, Simona (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Politics and Global Studies (Contributor)
Created2024-05
Description
Precise modulation of gene expression is essential for proper tissue and cell-specific differentiation and function. Multiple distinct post-transcriptional regulatory mechanisms, such as miRNA (microRNA)-based regulation and alternative polyadenylation (APA), are an intrinsic part of this modulation and orchestrate intricate pathways to achieve and maintain balanced gene expression.MiRNA-based regulation and APA function through sequence motifs located in the 3’ Untranslated Region (3’UTR) of mRNA transcripts. MiRNAs are short (~22 nt) non-coding RNA molecules that bind target sequences within the 3’UTR of an mRNA transcript, inhibiting its translation or promoting its degradation. APA occurs during RNA transcription termination and leads to the preparation of mature mRNAs with different 3’UTR lengths, allowing shorter 3’UTRs to bypass miRNA regulation.
In addition to these two post-transcriptional forms of regulation, co-transcriptional mechanisms such as alternative RNA splicing, which produces distinct gene products from a precursor mRNA, are also important in controlling gene expression.
While miRNA-based regulation, APA, and alternative RNA splicing are important regulatory mechanisms, there is a lack of comprehensive understanding of how they interact and communicate with each other. This thesis studies these three forms of gene regulation in the nematode C. elegans, with the goal of extracting rules and mechanisms used by each of them in development to establish and maintain somatic tissue identity.
After isolating miRNA targets in multiple C. elegans somatic tissues, it was found that miRNAs can modulate the abundance of hnRNPs and SR proteins, which are known to control alternative RNA splicing in a dosage-dependent manner.To identify tissue-specific miRNAs, a nuclear fluorescent cell sorting (FACS)-based methodology named Nuc-Seq, was developed to isolate and sequence tissue-specific miRNAs from body muscle tissue. Nuc-Seq identified 2,848 muscle-specific protein-coding genes and 16 body muscle-specific miRNAs. This data was used to develop a high-quality body muscle-specific miRNA-APA Interactome which allows studies in regulatory processes in detail.
Taken together, this work highlights some of the complexity of pre- and post-transcriptional gene regulation and sheds light on how miRNA-based regulation, APA, and alternative RNA splicing are interconnected and are responsible for the establishment and maintenance of tissue identity.
ContributorsSchorr, Anna L (Author) / Mangone, Marco (Thesis advisor) / Harris, Robin (Committee member) / Sharma, Shalini (Committee member) / Varsani, Arvind (Committee member) / Arizona State University (Publisher)
Created2023
Description
Despite the prevalence of coyotes (Canis latrans) little is known about the viruses associated with this species. To assess the extent of viral research that has been conducted on coyotes, a literature review was performed. Over the last six decades, there have been many viruses that have been identified infecting coyotes. The pathology of some cases implies that infection is rare and lethal while others have been demonstrated to be endemic to coyotes. In addition, the majority of the prior analyses were done through serological assays that were limited to investigating target viruses. To help expand what is known about coyote-virus dynamics, viral assays were conducted on coyote scat. The samples were collected as part of transects established along the Salt River near Phoenix, Arizona, United States (USA). The recovered viral genomes were clustered with other deoxynucleic acid (DNA) viruses and analyzed to determine phylogeny and genetic identity. From the recovered viral genomes, there are two novel circoviruses, one novel naryavirus, five unclassified cressdnaviruses, and two previously identified species of anelloviruses from the Wawtorquevirus genus. For these viruses, new phylogenies for their groups and pairwise identity plots have been generated. These figures give insight into the potential hosts and the evolutionary history. In the case of the anelloviruses, they likely derived from a wood rat (Neotoma) host, given the anellovirus family’s host specificity and its similarity to another viral genome derived from a wood rat in Arizona, USA. Of the recovered circovirus genomes, one is associated with a viral isolate collected from a dust sample in Arizona, USA. The second circovirus species identified is within a clade that consists of rodent associated circoviruses and canine circovirus. Other recovered genomes expand clusters of unclassified cressdnaviruses. The recovered genomes support further genomic analysis. These findings help support the notion that there is a wealth of viral information to be identified from animals like coyotes. By understanding the viruses that coyotes are associated with, it is possible to better understand the viral impact on the urban environment, domesticated animals, and wildlife in general.
ContributorsHess, Savage Cree (Author) / Varsani, Arvind (Thesis advisor) / Kraberger, Simona (Committee member) / Upham, Nathan S (Committee member) / Arizona State University (Publisher)
Created2023
Description
Alpha herpesviruses are a family of neuroinvasive viruses that infect multiplevertebrate species. Alpha herpesviruses are responsible for human and livestock infections, most notably Herpes Simplex Virus (HSV), Varicella Zoster virus (VZV), and Pseudorabies Virus (PRV). PRV is a potent swine virus that can infect other mammals, and results in lethal encephalitis that can be devastating to livestock and of great financial expense to farmers. HSV, types 1 and 2, and VZV are widespread throughout the global human population, with estimates of the HSV-1 burden at about 60% of people worldwide. The hallmark of alpha herpesvirus infection is a persistent, lifelong infection that can reactivate throughout the lifespan of the host. Currently, the precise mechanisms of how these viruses undergo intracellular trafficking to emerge from the infected cell in epithelial tissues is not well understood. Many insights have been made with PRV in animal neurons, both in culture systems and animal models, about the viral genes and host factors involved in these processes. However, understanding of these mechanisms, and the interplay between viral and host proteins, in the human pathogen HSV-1 is even more lacking. Using recombinant fluorescent virus strains of HSV-1 and Total Internal Reflection Microscopy to image the transport of mature viral progeny in epithelial cells, it was determined that the egress of HSV-1 uses constitutive cellular secretory pathways. Specifically, the viral progeny traffic from the trans-Golgi network to the site of exocytosis at the plasma membrane via Rab6a secretory vesicles. This work will contribute to the understanding of how alpha herpesviruses complete their lifecycles in host cells, particularly at the sites where infection initially occurs and can spread to a new organism. Knowledge of these processes may lead to the development of therapeutics or prophylactics to reduce the burden of these viruses.
ContributorsBergeman, Melissa Hope (Author) / Hogue, Ian B (Thesis advisor) / Hogue, Brenda (Committee member) / Roberson, Robert (Committee member) / Varsani, Arvind (Committee member) / Arizona State University (Publisher)
Created2023
Description
Food insecurity is an economic and social condition involving limited or uncertain access to food. The problem of food insecurity in communities is influenced by economic conditions, food deserts, and barriers to accessing healthy food. Individuals experiencing food insecurity often endure concurrent problems of financial instability, hunger, and poor mental and physical health. Public and non-profit services in the U.S., such as the federally supported Supplemental Nutrition Assistance Program (SNAP) and community food banks, provide food-related assistance to individuals who are at a high risk of experiencing food insecurity. Unfortunately, many individuals who qualify for these services still experience food insecurity due to barriers preventing them from accessing food, which may include inadequate finances, transportation, skills, and information. Effective approaches for removing barriers that prevent individuals from accessing food are needed to mitigate the increased risk of hunger, nutritional deficiencies, and chronic disease among vulnerable populations. This dissertation tested a novel food insecurity intervention using informational nudges to promote food security through the elimination of information barriers to accessing food. The intervention used in this mixed-methods feasibility study consisted of informational nudges in the form of weekly text messages that were sent to food pantry clients experiencing food insecurity. The study aims were to test the efficacy and acceptability of the intervention by examining whether the informational nudges could enhance food pantry utilization, increase SNAP registration, and promote food security. Quantitative study results showed a lower prevalence of food insecurity in the intervention group than the control group. Qualitative findings revealed how the intervention group found the text messages to be helpful and informative. These study findings can enhance future food insecurity interventions aiming to eliminate barriers that prevent individuals who are food insecure from accessing healthy food.
ContributorsRoyer, Michael F. (Author) / Wharton, Christopher (Thesis advisor) / Buman, Matthew (Committee member) / Der Ananian, Cheryl (Committee member) / MacKinnon, David (Committee member) / Ohri-Vachaspati, Punam (Committee member) / Arizona State University (Publisher)
Created2023
DescriptionA
ContributorsLund, Michael (Author) / Varsani, Arvind (Thesis advisor) / Upham, Nathan (Committee member) / Harris, Robin (Committee member) / Arizona State University (Publisher)
Created2023