Molecular Genetics Commons^™

A Cell Cycle-Regulated Toxoplasma Deubiquitinase, Tgotud3a, Targets Polyubiquitins With Specific Lysine Linkages, Animesh Dhara, Anthony P. Sinai

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The contribution of ubiquitin-mediated mechanisms in the regulation of the Toxoplasma gondii cell cycle has remained largely unexplored. Here, we describe the functional characterization of a T. gondii deubiquitinase (TGGT1_258780) of the ovarian-tumor domain-containing (OTU) family, which, based on its structural homology to the human OTUD3 clade, has been designated TgOTUD3A. The TgOTUD3A protein is expressed in a cell cycle-dependent manner mimicking its mRNA expression, indicating that it is regulated primarily at the transcriptional level. TgOTUD3A, which was found in the cytoplasm at low levels in G₁ parasites, increased in abundance with the progression of the …

Loss Of Cell Adhesion Increases Tumorigenic Potential Of Polarity Deficient Scribble Mutant Cells, Indrayani Waghmare, Madhuri Kango-Singh

Biology Faculty Publications

Epithelial polarity genes are important for maintaining tissue architecture, and regulating growth. The Drosophila neoplastic tumor suppressor gene scribble (scrib) belongs to the basolateral polarity complex. Loss of scrib results in disruption of its growth regulatory functions, and downregulation or mislocalization of Scrib is correlated to tumor growth. Somatic scribble mutant cells (scrib-) surrounded by wild-type cells undergo apoptosis, which can be prevented by introduction of secondary mutations that provide a growth advantage. Using genetic tools in Drosophila, we analyzed the phenotypic effects of loss of scrib in different growth promoting backgrounds. We investigated if a central …

Confirmation Of The Function Of Mrub1080 As Γ-Glutamyl Kinase (Prob) In Meiothermus Ruber, Cale J. Mccormick, Dr. Lori Scott

Celebration of Learning

This project is part of the Meiothermus ruber genome analysis project, which uses wet lab procedures and computational analysis to gather evidence of orthologous genes between Escherichia coli and Meiothermus ruber. In previous work, bioinformatics evidence supported the hypothesis that the gene Mrub1080 was an ortholog of E. coli proB. We investigated the biological function of Meiothermus ruber genes proB and proBA using the complementation assay. However, functional analysis proved inconclusive. For this particular research project, we confirmed that weakly complementing E. coli proB- null strains actually contained the desired M. ruber proB and proBA genes (inserted into a pKt1 …

Splice-Switching Antisense Oligonucleotides As Therapeutic Drugs, Mallory A. Havens, Michelle L. Hastings

Biology Department Faculty Articles

Splice-switching oligonucleotides (SSOs) are short, synthetic, antisense, modified nucleic acids that base-pair with a pre-mRNA and disrupt the normal splicing repertoire of the transcript by blocking the RNA–RNA base-pairing or protein–RNA binding interactions that occur between components of the splicing machinery and the pre-mRNA. Splicing of pre-mRNA is required for the proper expression of the vast majority of protein-coding genes, and thus, targeting the process offers a means to manipulate protein production from a gene. Splicing modulation is particularly valuable in cases of disease caused by mutations that lead to disruption of normal splicing or when interfering with the normal …

Effects Of Mutating The Mrub_1345 Gene Found In Meiothermus Ruber, Brandon M. Wills, Lori R. Scott

Celebration of Learning

Meiothermus ruber is a unique, red-pigmented, thermophilic bacterium that preferentially grows in high-temperature environments ranging from 35-70°C. Due to the lack of studies performed on this organism, there is quite a bit of information missing in regard to the genes found within this organism’s genome and their function. This study focuses in on the Mrub_1345 gene in M. ruber, which has been suggested to be orthologous to the proC gene found of E. coli proline biosynthesis pathway. To test if these genes are orthologs, we performed the complementation assay on wild-type proC. Next, we performed site-directed mutagenesis on amino acids …

Activation Of Target Gene Expression In Neurons By The C. Elegans Rfx Transcription Factor, Daf-19, Katherine P. Mueller

Lawrence University Honors Projects

DAF-19, the only RFX transcription factor found in C. elegans, is required for the formation of neuronal sensory cilia. Four isoforms of the DAF-19 protein have been reported, and the m86 nonsense (null) mutation affecting all four isoforms has been shown to prevent cilia formation. Transcriptome analyses employing microarrays of L1 and adult stage worms were completed using RNA from daf-19(m86) worms and an isogenic wild type strain to identify additional putative DAF-19 target genes. Using transcriptional fusions with GFP, we compared the expression patterns of several potential gene targets using fluorescence confocal microscopy. Expression patterns were characterized in …

The Role Of Daf-19 In Non-Ciliated Neurons: How Is Neural Development Regulated By Different Daf-19 Isoforms?, Zabdiel Ek Vazquez

Lawrence University Honors Projects

A degenerative disease-like phenotype, specifically reduction in synaptic protein levels in adult worms, is correlated with loss-of-function of the only RFX transcription factor gene, daf-19, in C. elegans. This gene encodes four known transcription factor isoforms, two of which are correlated with particular functions. The DAF-19C isoform activates genes responsible for cilia development, while DAF-19M is needed for cilia specification in males. A comparison of the transcriptome of daf-19 null and isogenic wild type adult worms suggests both positive and negative regulation of gene expression is correlated with the presence of DAF-19 proteins. We have assessed DAF-19 regulation …

Comparative Studies Of Tslp And Il-7 In Normal Early Human Neonatal And Adult B Cell Development, Terry-Ann Milford

Loma Linda University Electronic Theses, Dissertations & Projects

Defining the role of cytokines in promoting human B cell development is important for understanding B cell leukemia and for developing strategies to restore B cell production that is lost during some therapies. The purpose of this study was to investigate the roles of the IL-7R ligands, thymic stromal lymphopoietin (TSLP) and IL- 7, in the early stages of normal postnatal and adult human B cell development. Using novel in vitro and in vivo model systems, we show that TSLP and IL-7 are able to expand B cell precursors individually and in combination from CB hematopoietic stem cells. In this …

Hiv Vaccines: Progress, Limitations And A Crispr/Cas9 Vaccine, Omar A. Garcia Martinez

Biology: Student Scholarship & Creative Works

ABSTRACT: The HIV-1 pandemic continues to thrive due to ineffective HIV-1 vaccines. Historically, the world’s most infectious diseases, such as polio and smallpox, have been eradicated or have come close to eradication due to the advent of effective vaccines. Highly active antiretroviral therapy is able to delay the onset of AIDS but can neither rid the body of HIV-1 proviral DNA nor prevent further transmission. A prophylactic vaccine that prevents the various mechanisms HIV-1 has to evade and attack our immune system is needed to end the HIV-1 pandemic. Recent advances in engineered nuclease systems, like the CRISPR/Cas9 system, have …

Characterization Of The Marine Sponge Amphimedon Compressa Microbiome Across A Spatial Gradient, Renee Michelle Potens

HCNSO Student Theses and Dissertations

Diverse and ecologically important microbial communities (microbiomes) are symbiotic within marine sponges. In this study, the microbiome of Amphimedon compressa from three sample locations (Broward and Dade Counties, Southeast Florida, USA and the Southern Caribbean, Bocas del Toro, Panama) is characterized using 16S rRNA Illumina sequencing. The predominant taxa are Proteobacteria and Cyanobacteria, as expected for Low Microbial Abundance sponges, accounting for over 53% of the total microbiome community. The numbers of Operational Taxonomic Units (OTUs) decrease from Broward County (2,900) to Dade County (2,300) and then Bocas del Toro (1,200). The correlates to a decreasing north-south gradient of …

Identification Of Qtls For Resistance Against Rhizoctonia Solani And Phoma Glycinicola In Soybeans (Glycine Max L. Merr), Herbert Sserunkuma

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

A QTL (Quantitative trait locus) is a chromosome location of a gene controlling a specific phenotypic trait. The trait maybe governed by multiple genes. Fungal pathogens are responsible for over 50% of all soybean diseases. Rhizoctonia solani Kühn causes seedling dumping off, root and hypocotyl rots and other disease in soybeans. Phoma glycinicola de Gruyter & Boerema causes Red leaf blotch disease, predominantly in Sub-Saharan Africa. There is no reported complete resistance against these fungal pathogens in soybeans. Reaction to R.solani is reportedly a quantitative trait controlled by major and minor genes. Three QTLs contributing to reaction to R. solani …

Tropical Trees As Islands: Diversity Accumulation Of Armored Scale Insects (Hemiptera: Diaspididae) On Trees As A Function Of Forest Age, Hannah Shapiro

Undergraduate Honors Theses

Armored scale insects (Hemiptera: Diaspididae) are some of the most invasive insects in the world. These cryptic plant parasites are most often encountered in managed agricultural ecosystems, but very little is known about their distribution, abundance, and diversity in tropical rainforest canopies, where they are likely to have their highest diversity. Because these ubiquitous insects are extreme generalists with undirected dispersal, their diversity (alpha and beta) accumulation can conceivably be modeled according to tenets derived from island biogeography theory. For example, one expectation is that older established trees should boast a higher species diversity and abundance than younger ones. Other …

Diffuse Traumatic Brain Injury Induces Prolonged Immune Sysregulation And Potentiates Hyperalgesia Following A Peripheral Immune Challenge, Rachel K. Rowe, Gavin I. Ellis, Jordan L. Harrison, Adam D. Bachstetter, Gregory F. Corder, Linda J. Van Eldik, Bradley K. Taylor, Francesc Marti, Jonathan Lifshitz

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Background: Nociceptive and neuropathic pain occurs as part of the disease process after traumatic brain injury (TBI) in humans. Central and peripheral inflammation, a major secondary injury process initiated by the traumatic brain injury event, has been implicated in the potentiation of peripheral nociceptive pain. We hypothesized that the inflammatory response to diffuse traumatic brain injury potentiates persistent pain through prolonged immune dysregulation.

Results: To test this, adult, male C57BL/6 mice were subjected to midline fluid percussion brain injury or to sham procedure. One cohort of mice was analyzed for inflammation-related cytokine levels in cortical biopsies and serum along an …

Reverse Genetic Screening Of Innexin Gap Junction Proteins In Drosophila Neurons, Shannon P. Fox

Senior Honors Projects, 2010-2019

The reflexive response and perception of pain (nociception) is an evolutionarily conserved process in animals. Pain can be a major health concern and current treatments often prove insufficient, especially in regards to chronic pain. Greater understanding of the molecular processes underlying pain sensation could lead to new and more effective treatments. The aim of this study is to investigate the molecular mechanisms of cold nociception in Drosophila melanogaster. A specific subset of peripheral sensory neurons (Class III dendritic arborization (da) neurons), are implicated in Drosophila larvae’s response to noxious cold.

Previous literature has associated a family of gap junction protein, …

Epigenetic Characterization Of Human Retina Cells, Nicholas R. Dunham

Senior Honors Projects, 2010-2019

DNA methylation is an epigenetic modifier that modulates gene expression in plant and vertebrate genomes. The aim of this study was to characterize the role of DNA methylation in the human retina, particularly within rod and cone photoreceptor retinal neurons. Previous studies investigating DNA methylation in murine retinal cells and retina-derived human retinoblastoma immortalized cell culture lines demonstrate an inverse relationship between DNA methylation and transcriptional activity. Here, we used gene-specific bisulfite pyrosequencing analysis to measure DNA methylation in the genomes of human ocular cells in an effort to characterize the role of this important epigenetic modifier. These results can …

Investigation Of A Mycobacteriophage Transcription Repressor, Kathryn Orban

Honors Thesis

Mycobacteriophage HelDan is a lysogenic, or temperate, phage (virus) of the bacterium Mycobacterium smegmatis, which is a fast-growing, close relative of Mycobacterium tuberculosis, the causative agent of tuberculosis. The phage replication cycle is dependent on time-coordinated gene expression events. In order to study the regulation of gene expression during phage replication, HelDan protein gp73, a putative transcriptional repressor, was studied. Characterization of gp73 structure and function, such as DNA binding activity and affinity, was done using both bioinformatics and biochemical analyses. To this end, the gene encoding gp73 was cloned and the ability of the recombinant gp73 protein …

Mrub_2874 Is Homologous To B3386 And Mrub_1349 Is Homologous To B2914, But Mrub_1349 Is Not Homologous To B4090, Samantha Murad, Dr. Lori Scott

Meiothermus ruber Genome Analysis Project

ABSTRACT. This project is part of the Meiothermus ruber genome analysis project, which uses the bioinformatics tools associated with the Guiding Education through Novel Investigation – Annotation Collaboration Toolkit (GENI-ACT) to predict gene function. We investigated the biological function of the genes Mrub_2874 and Mrub_1349. We predict that Mrub_2874 encodes the enzyme ribulose-5-phosphate 3-epimerase (DNA coordinates 2912530..2913204 on the reverse strand), which is the first step of the pentose phosphate pathway (KEGG map number 00030). It catalyzes the conversion of D-ribulose 5-phosphate to D-xylulose 5-phosphate. The E. coli K12 MG1655 ortholog is predicted to be b3386, which has the gene …

Engineering A Mutation In The Heparin Binding Pocket Of The Human Fibroblast Growth Factor, Roshni Patel

Chemistry & Biochemistry Undergraduate Honors Theses

Fibroblast growth factors (FGFs) are family of proteins that belong to a group of growth factors that are found in mammals and play an important role in angiogenesis, differentiation, organogenesis, and tissue repair. In summary, their main functionality is involved in cell division and proliferation. Because FGFs plays such a vital role in cell proliferation, they are mainly involved in the process of wound healing and injuries. FGF binds to its ligand, heparin—a heavily sulfated glycosaminoglycan. The binding of heparin to FGF occurs through electrostatic interactions, specifically between the negatively charged sulfate groups on heparin and positively charged residues such …

The Uas-Gal4 System In D. Melanogaster: An Insight Into The Influence Of Micrornas On The Developmental Pathways Of The Wing, Emily R. Wilson

Honors Theses

By examining genetic pathways in D. melanogaster, a better understanding of the homologous regulatory mechanisms in humans can be utilized to further enhance knowledge of the roles of microRNA within development. This study utilizes the UAS-Gal4 system in order to produce a mutant phenotype capable of being visually studied and analyzed, focusing on the developmental pathway of the wing in D. melanogaster. Dissections of the wandering third instar larvae yielded wing disc tissue expressing the downregulation of loquacious and CG17386.

Alzheimer's Disease: The Silver Tsunami Of The 21st Century, Ankita Sarkar, Madison Irwin, Aditi Singh, Matthew Riccetti, Amit Singh

Biology Faculty Publications

Alzheimer's disease (AD), a fatal progressive neurodegenerative disorder, has no cure to date. One of the causes of AD is the accumulation of amyloid-beta 42 (Aß42) plaques, which result in the onset of neurodegeneration. It is not known how these plaques trigger the onset of neurodegeneration. There are several animal models developed to (i) study etiology of disease, (ii) look for genetic modifiers, and (iii) identify chemical inhibitors that can block neurodegeneration and help to find cure for this disease. An insect model of Drosophila melanogaster has also provided new insights into the disease. Here we will discuss the utility …