Biology Commons^™

Host Genetics And Geography Influence Microbiome Composition In The Sponge Ircinia Campana, Sarah M. Griffiths, Rachael E. Antwis, Luca Lenzi, Anita Lucaci, Donald C. Behringer, Mark J. Butler, Richard F. Preziosi

Biological Sciences Faculty Publications

1. Marine sponges are host to large, diverse communities of microorganisms. These microbiomes are distinct among sponge species and from seawater bacterial communities, indicating a key role of host identity in shaping its resident microbial community. However, the factors governing intraspecific microbiome variability are underexplored, and may shed light on the evolutionary and ecological relationships between host and microbiome.

2. Here, we examined the influence of genetic variation and geographic location on the composition of the Ircinia campana microbiome.

3. We developed new microsatellite markers to genotype I. campana from two locations in the Florida Keys, USA, and characterised their …

Unraveling The Neurogenin/Ngn-1 Gene Regulatory Network Of C. Elegans Using Classical Genetics And Comparative Transcriptomics, Elyse Christensen

Master of Science in Integrative Biology Theses

Proper nervous system development is required for an organism’s survival and function. Defects in neurogenesis have been linked to neurodevelopmental disorders such as schizophrenia and autism spectrum disorders. Understanding the gene regulatory networks that orchestrate neural development, specifically cascades of proneural transcription factors, can better elucidate which genes are most essential in governing early neurogenesis. Neurogenins are a family of such factors that are both sufficient and necessary for the development of neural sub-types in mice, primarily through the regulation of other factors, particularly NeuroD. The objective of this study was to evaluate previously established regulatory targets of neurogenin(ngn-1 …

Genome Of The Tropical Plant Marchantia Inflexa: Implications For Sex Chromosome Evolution And Dehydration Tolerance, Rose A. Marks, Jeramiah J. Smith, Quentin Cronk, Christopher J. Grassa, D. Nicholas Mcletchie

Biology Faculty Publications

We present a draft genome assembly for the tropical liverwort, Marchantia inflexa, which adds to a growing body of genomic resources for bryophytes and provides an important perspective on the evolution and diversification of land plants. We specifically address questions related to sex chromosome evolution, sexual dimorphisms, and the genomic underpinnings of dehydration tolerance. This assembly leveraged the recently published genome of related liverwort, M. polymorpha, to improve scaffolding and annotation, aid in the identification of sex-linked sequences, and quantify patterns of sequence differentiation within Marchantia. We find that genes on sex chromosomes are under greater …

The Anti-Sigma Factor Muca Of Pseudomonas Aeruginosa: Dramatic Differences Of A Muca22 Vs. A Δmuca Mutant In Anaerobic Acidified Nitrite Sensitivity Of Planktonic And Biofilm Bacteria In Vitro And During Chronic Murine Lung Infection, Warunya Panmanee, Shengchang Su, Michael J. Schurr, Gee W. Lau, Xiaoting Zhu, Zhaowei Ren, Cameron T. Mcdaniel, Long J. Lu, Dennis E. Ohman, Daniel A. Muruve, Ralph J. Panos, Hongwei D. Yu, Thomas B. Thompson, Boo Shan Tseng, Daniel J. Hassett

Life Sciences Faculty Research

Mucoid mucA22 Pseudomonas aeruginosa (PA) is an opportunistic lung pathogen of cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) patients that is highly sensitive to acidified nitrite (A-NO2-). In this study, we first screened PA mutant strains for sensitivity or resistance to 20 mM A-NO2- under anaerobic conditions that represent the chronic stages of the aforementioned diseases. Mutants found to be sensitive to A-NO2- included PA0964 (pmpR, PQS biosynthesis), PA4455 (probable ABC transporter permease), katA (major catalase, KatA) and rhlR (quorum sensing regulator). In contrast, mutants lacking PA0450 (a putative phosphate transporter) and PA1505 (moaA2) were A-NO2- resistant. However, …

Crispr/Cas9 In Yeast: A Multi-Week Laboratory Exercise For Undergraduate Students, Randi J. Ulbricht

Open Educational Resources

Providing undergraduate life-science students with a course-based research experience that utilizes cutting-edge technology, is tractable for students, and is manageable as an instructor is a challenge. Here, I describe a multi-week lesson plan for a laboratory-based course with the goal of editing the genome of budding yeast, Saccharomyces cerevisiae. Students apply knowledge regarding advanced topics such as: CRISPR/Cas9 gene editing, DNA repair, genetics, and cloning. The lesson requires students to master skills such as bioinformatics analysis, restriction enzyme digestion, ligation, basic microbiology skills, polymerase chain reaction, and plasmid purification. Instructors are led through the technical aspects of the protocols, …

Hippo Signaling In Cancer: Lessons From Drosophila Models, Kirti Snigdha, Karishma Sanjay Gangwani, Gauri Vijay Lapalikar, Amit Singh, Madhuri Kango-Singh

Biology Faculty Publications

Hippo pathway was initially identified through genetic screens for genes regulating organ size in fruitflies. Recent studies have highlighted the role of Hippo signaling as a key regulator of homeostasis, and in tumorigenesis. Hippo pathway is comprised of genes that act as tumor suppressor genes like hippo (hpo) and warts (wts), and oncogenes like yorkie (yki). YAP and TAZ are two related mammalian homologs of Drosophila Yki that act as effectors of the Hippo pathway. Hippo signaling deficiency can cause YAP- or TAZ-dependent oncogene addiction for cancer cells. YAP and TAZ are often activated …

Mapping A New Disease Resistance Locus In An F1 Progeny Derived From Two Grape Wild Relatives, Gaurab Bhattarai

Graduate Theses/Dissertations

Linkage maps and quantitative trait loci (QTL) analysis have become essential tools for the positional cloning of agronomically important genes and for marker-assisted breeding. In this study, two North American grape species, Vitis rupestris and Vitis riparia, and their 294 F₁ progeny were used to construct parental linkage maps and to perform QTL analysis for downy mildew resistance. Single nucleotide polymorphism (SNP) discovery was accomplished using genotyping-by-sequencing (GBS) and resulted in 348,888 SNPs. Of these, 11,063 informative SNP markers (3.17% of the original SNP dataset) were derived after filtering for various quality parameters and missing data. A two-way …

Warming Up: Climate Change Related Shifts Of Mycorrhizal Fungal Communities In High Latitude Ecosystems, Megan Rae Devan

Biology ETDs

This dissertation examines how climate change affects mycorrhizal fungal communities in boreal and arctic ecosystems. In chapter one, I revealed that increases in fire severity and related increases in deciduous tree dominance result in greater Ascomycota relative abundance (RA) and subsequent declines in Basidiomycota RA. In chapter two I analyzed the effects of post-fire mycorrhizal fungal communites on host growth. There were trends at the fungal genus level that were largely reflected at the guild level across all hosts; however, there were some fungal genera that had the opposite effect on different host species. In chapter three, I found host …

Fungi In A Hot, Dry, Changing World, Miriam I. Hutchinson

Biology ETDs

My doctoral work focused on understanding the reciprocal relationship between fungi and their environment, namely how fungi respond to environmental flux, as well as how fungi can modify and structure their habitats, especially in the context of climate change. As such, I aimed my research on fungi with distinct adaptations to their environmental niches: endophytic fungi that inhabit plant tissue and thermophilic fungi that are capable of growing at the upper temperature limit for eukaryotic life. My research consisted of three studies. First, I investigated the thermophilic species Myceliophthora heterothallica to demonstrate its use as a model organism for efficient …

Rising Rural Body-Mass Index Is The Main Driver Of The Global Obesity Epidemic In Adults, Con Burns, Tara Coppinger, Janette Walton, Et Al

Publications

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities1,2. This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity3,4,5,6. Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to …

Detecting The Cold: Do Innexins Function In Cold Nociception?, Rachel Barborek

Senior Honors Projects, 2010-2019

Nociception is the perception of and response to harmful stimuli. Nociception is essential for minimizing tissue damage, but aberrant nociceptive pathways can result in chronic pain. Chronic pain in the U.S. is commonly managed with wide-acting opioids, and precisely defining the components of nociceptive pathways could uncover novel targets for pain therapies. I hypothesize that the vitally quick process of nociception would utilize electrical synapses because they transmit signals between neurons more quickly than chemical synapses do. This study, therefore, aims to uncover the potential role of the eight Drosophila melanogaster gap junction proteins, the Innexins, in cold nociception. Wild …

Fusarium Euwallacea: A Serious Threat To The Native And Ornamental Trees And Shrubs In Southern California, Greg Tyler, Yixing Zheng, Michael Kulinich, Hagop Atamian

Student Scholar Symposium Abstracts and Posters

Fusarium Euwallacea is a fungus that has established symbiotic relationship with the beetle Euwallacea aff. fornicata. The beetle bores through the tree bark and into the sapwood making long tunnels inside the trees. The beetle carries the F. Euwallacea in a specialized structure on its body called mandibular mycangia and cultivates the fungus in the tunnels on which the beetle feeds to grow and reproduce. The growth of the fungus obstructs water and mineral transport in the plant xylem tissue, resulting in dieback, wilt and mortality of the host tree. Fungi are known to secrete proteins called effectors in …

Surveying Apicomplexan Diversity And Dynamics In Narragansett Bay, Evelyn Spencer

Senior Honors Projects

Parasites play an important role in marine ecosystems and their diversity is generally understudied. Apicomplexans, a group of parasitic protists in the phylum Alveolata, infect a wide variety of animal hosts and are abundant in ecosystems spanning from Polar Regions to Neotropical rainforests. Previous data generated from marine sediments in Antarctica, Naples Bay, and off the coast of Oslo, exhibit high diversity and numbers of apicomplexans. Abundance and diversity of these protists are unknown for Narragansett Bay, despite the fact that they infect many commercially important species. The aim of my study was to obtain abundance data and understand genetic …

Methylation-Specific Differentiation Of Vaginal Epithelial Cells For Forensic Tissue Typing By Bisulfite Conversion And Pyrosequencing, Elise Pood

Master's Theses

The identification of bodily fluids and tissues is often applied to criminal investigations to clarify events that may or may not have taken place. Current forensic techniques can identify blood, saliva, seminal fluid, and spermatozoa, but there is a clear absence of reliable testing to identify vaginal epithelial tissue. Though there are serological tests available for this purpose, tissue-specific methylation markers have recently been investigated as a candidate for the identification of blood, saliva, and spermatozoa.

In this study, tissue-specific methylation markers were analyzed to identify a set of markers for the differentiation of vaginal fluid from blood, saliva, and …

Thiol-Based Misfolding: Linking Redox Balance To Cytosolic Proteostasis, Ford Amy

Dissertations and Theses (Open Access)

The eukaryotic cytosolic proteome is vulnerable to changes in proteostatic and redox balance caused by temperature, pH, oxidants and xenobiotics. Cysteine-containing proteins are especially at risk as the thiol side chain is subject to oxidation, adduction and chelation by thiol-reactive compounds. All of these thiol-modifiers have been demonstrated to induce the heat shock response and recruit protein chaperones to sites of presumed protein aggregation in the budding yeast Saccharomyces cerevisiae. However, endogenous targets of thiol stress toxicity responsible for these outcomes are largely unknown. Furthermore, I hypothesize proteins identified as redox-active are prone to misfolding and aggregation by thiol-specific …

Higher Order Chromosome Organization And Recombination Dynamics Of Meiotic Prophase I In Mouse Spermatocytes, Rhea Kang

Dissertations and Theses (Open Access)

Meiotic recombination is required for parental chromosomes to find each other (pairing/synapsis) and to exchange genetic information thus allowing faithful segregation of chromosomes and the production of haploid gametes. At the start of meiotic prophase I, meiotic chromosomes organize into loop arrays that extrude out of the chromosome axis. Then, a large number of programmed double-strand breaks (DSBs) are formed at specific chromosomal locations or “hotspots” on parental chromosomes, which are repaired by homologous recombination (HR). HR produces either crossovers, which result in the exchange of flanking markers between homologs, or noncrossovers, which are short regions ofgene conversion to the …

Cellular Localization Of Rad51d Mutant Proteins And The Application Of Art To Increase Scientific Literacy In America, Claire L. Chabot

Senior Theses

Ovarian cancers are the leading cause of death from cancer of the female reproductive system. Approximately 50% of ovarian cancers have defects in the homologous recombination (HR) DNA repair pathway that is required for the repair of DNA double-stranded breaks. The status of HR genes, such as BRCA1, BRCA2, and the RAD51 family, contributes to ovarian cancer development as well as treatment decisions regarding chemotherapy, radiation, and immunotherapy. The overarching goal of this project is to identify new insights into HR that can integrate with Precision Medicine Initiatives and align with the goals of the Cancer Moonshot 2020 Program. I …

The Role And Regulation Of Alternative Polyadenylation In The Dna Damage Response, Michael R. Murphy

Dissertations, Theses, and Capstone Projects

Cellular homeostasis is achieved by the dynamic flux in gene expression. Post-transcriptional regulation of coding and non-coding RNA offers a fast method of adapting to a changing cellular environment, including deadenylation, microRNA (miRNA) pathway, and alternative polyadenylation (APA). In this dissertation, I explored some of the mechanisms involved in the post-transcriptional regulation of gene expression. The main hypothesis in these studies is that a single APA event after DNA damage is governed by specific conditions and factors outside of current known regulators of APA, and that the resultant transcript has a role in the DNA damage response (DDR). My aims …

Characterization Of Developmental Genes In Streptomyces, Erin Orr

Undergraduate Distinction Papers

Characterization of two developmental genes in Streptomyces was carried out by different genetic manipulation techniques in two different species. The construction of an overexpression mutant for a gene encoding a putative c-di-GMP binding protein in Streptomyces scabies was started. This gene was found to be a homologue of a protein that was found to bind to c-di-GMP in a protein binding assay that consisted of streptavidin coated beads and biotinylated c-di-GMP. Attempts at cloning the gene encoding this protein into an overexpression construct were made. Another developmental gene was also investigated. Gene disruption by PCR targeting was used to isolate …

Phylogeny Of The Australian Solanum Dioicum Group Using Seven Nuclear Genes: Testing Symon’S Fruit And Seed Dispersal Hypotheses., Christopher T. Martine, Ingrid E. Jordon-Thaden, Angela J. Mcdonnell, Jason T. Cantley, Daniel S. Hayes, Morgan D. Roche, Emma S. Frawley, Ian S. Gilman, David C. Tank

Faculty Journal Articles

The dioecious and andromonoecious Solanum taxa (the “S. dioicum group”) of the Australian Monsoon Tropics have been the subject of phylogenetic and taxonomic study for decades, yet much of their basic biology is still unknown. This is especially true for plant-animal interactions, including the influence of fruit form and calyx morphology on seed dispersal. We combine field/greenhouse observations and specimen-based study with phylogenetic analysis of seven nuclear regions obtained via a microfluidic PCR-based enrichment strategy and high-throughput sequencing, and present the first species-tree hypothesis for the S. dioicum group. Our results suggest that epizoochorous trample burr seed …

Co-Occurrence Of Manganese Oxidase Genes Indicates Lateral Transfer Between Classes Of Proteobacteria, Jacob Olichney

Student Scholar Showcase

Pseudomonas putida GB-1 is a model organism for the study of manganese oxidation in bacteria, however, the frequency of co-localization of multiple known and suspected manganese oxidizing proteins, as well as their occurrence between species, is unknown. Eight different genes isolated from known manganese oxidizing bacteria (MnxG, MopA, McoA, PputGB1_2552, PputGB1_2553, MoxA, MofA, and Bacillus MnxG) were tested individually using BioPython and BLAST (Basic Local Alignment Search Tool) on multiple genomic databases. BLAST searches had an expect value cutoff of 1e-50, limiting gene homologs to those with high sequence similarity. The abundance of homologous genes across classes of proteobacteria point …

The Sucking Louse Fauna Of Mongolian Rodents: Host Associations, Molecular Phylogenetics And Description Of Two New Species, Chase N. Robinson

Honors College Theses

This study aimed to screen Mongolian rodents for sucking lice (Insecta: Phthiraptera: Anoplura) to better understand host-parasite associations for this understudied region. Nine species, including 3 previously undescribed, from 4 genera were identified. A molecular phylogeny based on 2 mitochondrial genes of collected louse specimens is included.

Molecular Evolutionary Trends And Feeding Ecology Diversification In The Hemiptera, Anchored By The Milkweed Bug Genome, Kristen A. Panfilio, Iris M. Vargas Jentzsch, Joshua B. Benoit, Deniz Erezyilmaz, Yuichiro Suzuki, Stefano Colella, Hugh M. Robertson, Monica F. Poelchau, Robert M. Waterhouse, Panagiotis Ioannidis, Matthew T. Weirauch, Daniel S. T. Hughes, Shwetha C. Murali, John H. Werren, Chris G. C. Jacobs, Elizabeth J. Duncan, David Armisén, Barbara M. I. Vreede, Patrice Baa-Puyoulet, Chloé S. Berger, Chun-Che Chang, Hsu Chao, Mei-Ju M. Chen, Yen-Ta Chen, Christopher P. Childers, Ariel D. Chipman, Andrew G. Cridge, Antonin J. J. Crumière, Peter K. Dearden, Elise M. Didion, Subba Reddy Palli, Jayendra Nath Shukla

Entomology Faculty Publications

Background: The Hemiptera (aphids, cicadas, and true bugs) are a key insect order, with high diversity for feeding ecology and excellent experimental tractability for molecular genetics. Building upon recent sequencing of hemipteran pests such as phloem-feeding aphids and blood-feeding bed bugs, we present the genome sequence and comparative analyses centered on the milkweed bug Oncopeltus fasciatus, a seed feeder of the family Lygaeidae.

Results: The 926-Mb Oncopeltus genome is well represented by the current assembly and official gene set. We use our genomic and RNA-seq data not only to characterize the protein-coding gene repertoire and perform isoform-specific RNAi, but …

X-Inactivation And Epigenetics, Serena Weston

Thinking Matters Symposium Archive

To prevent abnormal development caused by expressing both X chromosomes, female mammals inactivate one of their X chromosomes using an epigenetic process called dosage compensation. This literature review examines how X chromosome inactivation (XCI) occurs during the formation and development of an embryo. This condensation of DNA is marked by histone tail modifications, DNA methylation, and the arrival of structural proteins resulting in extraordinarily stable heterochromatin. X-inactivation is regulated in cis by the X-inactivation center (Xic) that contains the Xist gene and its antisense gene, Tsix. On one X chromosome, Xist RNA is expressed and coats the center of the …

Male Determining Gene Nix May Bring An End To Transmission Of Diseases Through Mosquitoes, Mohammed Mahdi

Thinking Matters Symposium Archive

Female mosquitoes take blood from humans to gain protein needed to produce eggs, and in the process they can transmit viruses, such as Zika, Dengue, and chikungunya, or parasites, such as malaria. Male mosquitoes do not transmit diseases. This literature review will examine what is known about how sex is determined in mosquitoes and how this can be used to manipulate the females that spread diseases to humans. Using CRISPR Cas9, the lab of Zhijian Tu removed the Nix gene from mosquito embryos; all of these were feminized. Ectopic overexpression of Nix gene product in mosquito embryos caused even genetically …

Identification And Functional Testing Of Novel Interacting Protein Partners For The Stress Sensors Wsc1p And Mid2p Of Saccharomyces Cerevisiae, Ednalise Santiago-Cartagena, Sahily González-Crespo, Vladimir Vélez, Nelson Martínez, Jamie Snider, Matthew Jessulat, Hiroyuki Aoki, Zoran Minic, Pearl Akamine, Inoushka Mejías, Luis M. Pérez, Brian C. Rymond, Mohan Babu, Igor Stagljar, José R. Rodríguez-Medina

Biology Faculty Publications

Wsc1p and Mid2p are transmembrane signaling proteins of cell wall stress in the budding yeast Saccharomyces cerevisiae. When an environmental stress compromises cell wall integrity, they activate a cell response through the Cell Wall Integrity (CWI) pathway. Studies have shown that the cytoplasmic domain of Wsc1p initiates the CWI signaling cascade by interacting with Rom2p, a Rho1-GDP-GTP exchange factor. Binding of Rom2p to the cytoplasmic tail of Wsc1p requires dephosphorylation of specific serine residues but the mechanism by which the sensor is dephosphorylated and how it subsequently interacts with Rom2p remains unclear. We hypothesize that Wsc1p and Mid2p must …

Streptococcus Agalactiae Strains With Chromosomal Deletions Evade Detection With Molecular Methods, Isabella A. Tickler, Fred C. Tenover, Scott Dewell, Victoria M. Le, Rachel N. Blackman, Richard V. Goering, Amy E. Rogers, Heather Piwonka, Brittney D. Jung-Hynes, Derrick J. Chen, Michael J. Loeffelholz, Devasena Gnanashanmugam, Ellen Jo Baron

Biology Faculty Publications

Surveillance of circulating microbial populations is critical for monitoring the performance of a molecular diagnostic test. In this study, we characterized 31 isolates of Streptococcus agalactiae (group B Streptococcus [GBS]) from several geographic locations in the United States and Ireland that contain deletions in or adjacent to the region of the chromosome that encodes the hemolysin gene cfb, the region targeted by the Xpert GBS and GBS LB assays. PCR-negative, culture-positive isolates were recognized during verification studies of the Xpert GBS assay in 12 laboratories between 2012 and 2018. Whole-genome sequencing of 15 GBS isolates from 11 laboratories revealed …

Plant Mitochondrial Genome Evolution And Structure Has Been Shaped By Double-Strand Break Repair And Recombination, Emily Wynn

School of Biological Sciences: Dissertations, Theses, and Student Research

Plant mitochondrial genomes are large but contain a small number of genes. These genes have very low mutation rates, but genomes rearrange and expand at significant rates. We propose that much of the apparent complexity of plant mitochondrial genomes can be explained by the interactions of double-strand break repair, recombination, and selection. One possible explanation for the disparity between the low mutation rates of genes and the high divergence of non-genes is that synonymous mutations in genes are not truly neutral. In some species, rps14 has been duplicated in the nucleus, allowing the mitochondrial copy to become a pseudogene. By …

Genomics Based Approaches To Fungal Evolution, Aaron J. Robinson, Donald O. Natvig

Biology ETDs

Advances in DNA sequencing and data analysis make it possible to address questions in population genetics and evolution at the genomic level. Fungi are excellent subjects for such studies, because they are found in diverse environments, have short generation times, can be maintained in culture and have relatively small genomes. My research employed genetic approaches using a variety of sequencing technologies and methods of analysis to explore questions in fungal evolution.

In one study, I explored the genetics behind differences in thermotolerance between isolates of Neurospora discreta from Alaska and New Mexico. Isolates from the two states exhibited differences in …

Cryptic Lineages And A Population Damned To Incipient Extinction? Insights Into The Genetic Structure Of A Mekong River Catfish, Amanda S. Ackiss, Binh T. Dang, Christopher E. Bird, Ellen E. Biesack, Phen Chheng, Latsamy Phounvisouk, Quyen H.D. Vu, Sophorn Uy, Kent E. Carpenter

Biological Sciences Faculty Publications

An understanding of the genetic composition of populations across management boundaries is vital to developing successful strategies for sustaining biodiversity and food resources. This is especially important in ecosystems where habitat fragmentation has altered baseline patterns of gene flow, dividing natural populations into smaller sub-populations and increasing potential loss of genetic variation through genetic drift. River systems can be highly fragmented by dams built for flow regulation and hydropower. We used reduced-representation sequencing to examine genomic patterns in an exploited catfish, Hemibagrus spilopterus, in a hotspot of biodiversity and hydropower development- the Mekong River basin. Our results revealed the …