Cell and Developmental Biology Commons^™

Genetic Analysis Of Serf Gene Function In Drosophila Melanogaster And Its Contribution To A Fly Model Of Spinal Muscular Atrophy, Swagata Ghosh

Theses and Dissertations--Biology

The Serf gene is evolutionarily highly conserved but its biological function is not known in any organism. In human, SERF1/H4F5 was first identified as a modifier of the disease Spinal Muscular Atrophy (SMA). SMA is caused by mutations in the Survival Motor Neuron 1(SMN1) gene leading to diminished levels of the Smn protein. More than 90% of patients with the most severe form of SMA have deletions that remove SERF1 as well as mutaions within SMN1. Hence, loss of Serf activity is hypothesized to exacerbate SMA disease progression. The primary motivation of this thesis was to test …

Macropinosome Maturation Is A Clathrin Dependent Process In Bone Marrow Macrophages, Susmita Poudel

Electronic Theses and Dissertations

Macrophages nonspecifically take up extracellular fluids, solutes and macromolecules by macropinocytosis. Understanding the mechanisms of macropinosome maturation will inform the study of lipid uptake, viral entry, antigen processing and presentation, as well as regulation of cell growth. Colony stimulating factor-1 receptor (CSF-1R) is internalized by small vesicle endocytosis, trafficked to nascent macropinosomes and degraded. These CSF-1R positive macropinosomes mature through a sequence similar to endosomes, progressing from EEA1 and Rab5 to Rab7 positive vesicles before fusing with lysosomes. Here we report the assembly of clathrin on internalized macropinosomes shown both by live-cell microscopy of cells expressing clathrin light chain-yellow fluorescent …

Lipid-Laden Macrophages Downregulate Akt Phosphorylation And Metabolize Lipid Droplets Via Autophagy, Rifat Sultana

Electronic Theses and Dissertations

Macrophages contribute to plaque formation in atherosclerosis. Macrophages take up modified low-density lipoproteins and store excess cholesterol and triglycerides in lipid droplet organelles. Evidence of lipid-laden macrophages or “foam cells” is apparent on histology sections of diseased arteries, and this lipid-laden appearance can be recreated in cell culture upon exposure of cultured macrophages to acetylated LDL (Ac-LDL). Under nutrient stress, neutral lipids in lipid droplets are hydrolyzed by lipolysis, autophagy, or both. However, these processes are not well understood in macrophages. We created lipidladen macrophages by 24-h exposure to Ac-LDL and analyzed dynamics of lipid droplet metabolism following removal of …

An Undergraduate Cell Biology Lab: Western Blotting To Detect Proteins From Drosophila Eye, Neha Gogia, Ankita Sarkar, Amit Singh

Biology Faculty Publications

We have developed an undergraduate laboratory to allow detection and localization of proteins in the compound eye of Drosophila melanogaster, a.k.a fruit fly. This lab was a part of the undergraduate curriculum of the cell biology laboratory course aimed to demonstrate the use of Western Blotting technique to study protein localization in the adult eye of Drosophila. Western blotting, a two-day laboratory exercise, can be used to detect the presence of proteins of interests from total protein isolated from a tissue. The first day involves isolation of proteins from the tissue and SDS-PAGE (sodium dodecyl sulfate-polyacrylamide) gel …

Real-Time Quantitative Pcr To Demonstrate Gene Expression In An Undergraduate Lab, Abijeet Singh Mehta, Amit Singh

Biology Faculty Publications

The objective of this teaching note is to develop a laboratory exercise, which allows students to get a hands-on experience of a molecular biology technique to analyze gene expression. The short duration of the biology laboratory for an undergraduate curriculum is the biggest challenge with the development of new labs. An important part of cell biology or molecular biology undergraduate curriculum is to study gene expression. There are many labs to study gene expression in qualitative manner. The commonly used reporter gene expression studies are primarily qualitative. However, there is no hands-on experience exercise to quantitatively determine gene expression. Therefore, …

Investigating Mirna Functions In Arabidopsis By Short Tandem Target Mimic (Sttm), Yiyou Gu

Dissertations, Master's Theses and Master's Reports

MicroRNA (miRNAs) and other endogenous small RNAs play important role in regulating gene expression in eukaryotes. Till now, several techniques have been developed for miRNA function analysis. Because of the characteristic of miRNAs, the most applicable method for miRNA function research is blocking the whole miRNA family specifically. Here, we report an artificial non-coding transcript termed Short Tandem Target Mimic (STTM) for blocking miRNA activity in Arabidopsis thaliana. The STTM composed of two miRNA target sites with three nucleotides bulge in the miRNA cleavage site, the two-miRNA targets separated by spacer linker. We used this technique blocking several important endogenous …

4-Nonylphenol Induces Neurodegeneration By Altering Cytoskeleton, Cynthia Carreon

Open Access Theses & Dissertations

4-nonylphenol (4-NP), an endocrine-disrupting compound (EDC), has been shown to affect brain development and may cause neurodegeneration. In the environment, 4-NP arises as a degradation product of alkylphenol polyethoxylates, compounds widely used as nonionic surfactants in commercial production, as well as in herbicides, pesticides, polystyrene plastics, and paints and has been shown to undergo a high level of accumulation in biological tissues. However, the mechanism by which 4-NP exerts its effect is not understood. Recent results from our laboratory indicate that Gβγ, an important component of the G protein-signaling pathway, induces neuronal outgrowth and differentiation by modulating microtubule (MT) assembly, …

Targeting Apoptotic Pathways To Overcome Drug Resistance In Acute Myeloid Leukemia, Rongqing Pan

Dissertations and Theses (Open Access)

Evasion of apoptosis is integral to tumorigenesis and drug resistance. BCL-2 and p53 proteins represent two focal nodes in convergent apoptosis signaling. Upregulation of anti-apoptotic BCL-2 family members and inactivation of p53 functions are two canonical approaches exploited by cancer cells to escape apoptosis. In the current study, we find that BCL-2 protein is highly expressed in acute myeloid leukemia (AML) cells. BCL-2–specific inhibitor ABT-199 potently induces mitochondrial apoptosis in AML cells and effectively kills AML stem/progenitor cells. Our biomarker studies demonstrate that both BH3 profiling and the expression profiling of BCL-2 proteins may serve as predictive biomarkers for the …

Identifying The Function Of The Calpain Small Subunit In The Mechanics Of Cell Migration, Bingqing Hao

Wayne State University Dissertations

Cell migration plays a vital role in many physiological events including: morphogenesis, wound healing, and immune response. Dysfunctional cell migration results in multiple disease states including chronic inflammation, vascular disease, and tumor metastasis, to name a few. Progress in understanding the mechanism of cell migration had been slow until the turn of the century when rapid technological advances in microscopy and omics burst to the forefront. These advances led to the realization that physical factors (dimensions, fluid shear stress, hydrostatic pressure, compression stress, environmental stiffness, and topography) have profound effects on cell migration. This study of cell mechanics has expanded …

Identification Of Oxygen Optima For Mouse Trophoblast Stem Cells And Human Embryos And The Stress Responses Upon Departing Optima, Yu Yang

Wayne State University Dissertations

Low level of oxygen (O2) occurs physiologically during in vivo embryo development. As developing embryos moving from fallopian tube to uterus, oxygen level gradually decreases to ≤ 5% at the time of blastocyst implantation. Blastocysts are made of two major cell populations, trophoblast cells and inner cell mass, from which trophoblast stem cells (TSCs) and embryonic stem cells (ESCs) are derived respectively. TSCs serve as placental stem cells that later on proliferate and differentiate into placenta. Previous study has shown that 2% O2 is the optimal O2 level for mTSC in vitro growth and potency maintenance, which agrees with their …

Zebrafish (Danio Rerio) As A Model For Orofacial Research, Kevin A. Ghaffari

Theses and Dissertations

Across species, the face and more specifically the mouth, serves as an essential facet of everyday life. Amongst humans the mouth serves as a tool for the ingestion of food, a marker for facial recognition and a medium for communication. In order for the mouth to properly form, a series of precise growth and fusion events are needed. In order to insure that these events are orchestrated properly is a wide array of signals, transcription factors and epigenetic regulators. Due to the needed precision of these events, congenital birth defects of the face such as cleft lip and cleft palate …

Cullin-4 Regulates Wingless And Jnk Signaling-Mediated Cell Death In The Drosophila Eye., Meghana Tare, Ankita Sarkar, Shimpi Bedi, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

In all multicellular organisms, the fundamental processes of cell proliferation and cell death are crucial for growth regulation during organogenesis. Strict regulation of cell death is important to maintain tissue homeostasis by affecting processes like regulation of cell number, and elimination of unwanted/unfit cells. The developing Drosophila eye is a versatile model to study patterning and growth, where complex signaling pathways regulate growth and cell survival. However, the molecular mechanisms underlying regulation of these processes is not fully understood. In a gain-of-function screen, we found that misexpression of cullin-4 (cul-4), an ubiquitin ligase, can rescue reduced eye mutant phenotypes. Previously, …

The Replication Initiator Of The Cholera Pathogen’S Second Chromosome Shows Structural Similarity To Plasmid Initiators, Natalia Orlova, Matthew Gerding, Olha Ivashkiv, Paul Dominic B. Olinares, Brian T. Chait, Matthew K. Waldor, David Jeruzalmi

Publications and Research

The conserved DnaA-oriC system is used to initiate replication of primary chromosomes throughout the bacterial kingdom; however, bacteria with multipartite genomes evolved distinct systems to initiate replication of secondary chromosomes. In the cholera pathogen, Vibrio cholerae, and in related species, secondary chromosome replication requires the RctB initiator protein. Here, we show that RctB consists of four domains. The structure of its central two domains resembles that of several plasmid replication initiators. RctB contains at least three DNA binding winged-helix-turn-helix motifs, and mutations within any of these severely compromise biological activity. In the structure, RctB adopts a headto- head dimeric configuration …

The Study Of The Functions And Regulation Of Mammalian Cap1 (Cyclase-Associated Protein 1), Haitao Zhang

Student Theses and Dissertations

CAP is a conserved actin-binding protein with versatile roles in promoting actin dynamics across species. Mammalian CAPs had been understudied compared to the first identified yeast homologues; their cellular functions remained to be better established. Moreover, CAP function regulation remained a completely uncharted area. Recent studies also implicated CAP in the invasiveness of human cancers. However, some of the evidence was not convincing and further studies were needed. The present study established and identified new cellular functions for mammalian CAP1, identified a regulatory mechanism as phosphorylation at the S307/S309 tandem site along with the cell signals controlling both phosphorylation and …

A Novel Rrm3 Function In Restricting Dna Replication Via An Orc5-Binding Domain Is Genetically Separable From Rrm3 Function As An Atpase/Helicase In Facilitating Fork Progression, Salahuddin Syed, Claus Desler, Lene J Rasmussen, Kristina H Schmidt

Molecular Biosciences Faculty Publications

In response to replication stress cells activate the intra-S checkpoint, induce DNA repair pathways, increase nucleotide levels, and inhibit origin firing. Here, we report that Rrm3 associates with a subset of replication origins and controls DNA synthesis during replication stress. The N-terminal domain required for control of DNA synthesis maps to residues 186-212 that are also critical for binding Orc5 of the origin recognition complex. Deletion of this domain is lethal to cells lacking the replication checkpoint mediator Mrc1 and leads to mutations upon exposure to the replication stressor hydroxyurea. This novel Rrm3 function is independent of its established role …

Nucelotide Substitution Rates In Hantavirus Cd8+ T-Cell Epitopes, Brian Gerald Sikes

Graduate Theses

Hantaviruses pathogenic to humans are exclusive to rodents. Typically each hantavirus is associated with only one host species. Due to their close association, the geographical distributions are the same. Old World species, such as Hantaan hantavirus and Puumala hantavirus, induce symptoms described as the Hemorrhagic Fever with Renal Syndrome (HFRS). The New World hantaviruses, such as Andes hantavirus and Sin Nombre hantavirus, share a suite of symptoms that have been described as Hantavirus Pulmonary Syndrome (HPS). In this study, 16 well-characterized cytotoxic T lymphocytes (CTL) epitopes of the nucleocapsid (N) protein were identified from the literature.

These 16 …

Establishing A Novel Culture System Using 3d Printing To Induce Osteogenesis In Mc3t3-E! Osteoblasts, Lisa Carder

Graduate Theses

Whole organ tissue engineering represents a potential solution to the problem of organ shortage and host rejection; however, the process of producing a three-dimensional, functional organ is extremely complex. Research has used three-dimensional printing in order to combat the cost and time constraints that come with whole organ studies. This project created 3D scaffolds based on the trabecular portion of a sheep talus. Using these raw materials, pre-osteoblasts were injected onto the scaffold to test their proliferation within the 3D space. The purpose of this study was to create a three dimensional environment that was able to be coated and …

Ros Regulation Of Axonal Mitochondrial Transport, Pin-Chao Liao

Open Access Dissertations

Mitochondria perform critical functions including aerobic ATP production and calcium (Ca2+) homeostasis, but are also a major source of reactive oxygen species (ROS) production. To maintain cellular function and survival in neurons, mitochondria are transported along axons, and accumulate in regions with high demand for their functions. Oxidative stress and abnormal mitochondrial axonal transport are associated with neurodegenerative disorders. However, we know little about the connection between these two. Using primaryDrosophila neuronal cell culture and the third instar larval nervous system as in vitro and in vivo models, respectively, we studied mitochondrial transport under oxidative stress conditions. In vitro …

Pharmacokinetics, Tissue Distribution, Synergistic Activity, And Antitumor Activity Of Two Isomeric Flavones, Crystal L. Whitted

Electronic Theses and Dissertations

Flavonoids are polyphenolic secondary metabolites found in plants that have bioactive properties including antiviral, antioxidant, and anticancer. Two isomeric flavone were extracted from Gnaphalium elegans and Achyrocline bogotensis, plants used by the people from the Andean region of South America as remedies for cancer. 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5, 7–dihydroxy- 3, 6, 8 trimethoxy flavone/ flavone A) and 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3, 5–dihydroxy-6, 7, 8–trimethoxy flavone/ flavone B) have shown antineoplastic activity against colon cancer cell lines dependent upon their differentiation status. Pharmacokinetic studies reported herein were used to determine dosing for antitumor assays, as well as determine target tissue concentration. These included the …

Microenvironment-Induced Pten Loss By Exosomal Microrna Primes Brain Metastasis Outgrowth, Lin Zhang

Dissertations and Theses (Open Access)

Development of life-threatening cancer metastases at distant organs requires disseminated tumor cells’ adaptation to and co-evolution with the drastically different microenvironments of metastatic sites. Cancer cells of common origin manifest distinct gene expression patterns after metastasizing to different organs. Clearly, the dynamic interplay between metastatic tumor cells and extrinsic signals at individual metastatic organ sites critically impacts the subsequent metastatic outgrowth. Yet, it is unclear when and how disseminated tumor cells acquire the essential traits from the microenvironment of metastatic organs that prime their subsequent outgrowth. Here we show that primary tumor cells with normal expression of PTEN, an important …

Discrete Mutations In Colorectal Cancer Correlate With Defined Microbial Communities In The Tumor Microenvironment, Michael B. Burns, Emmanuel Montassier, Juan Abrahante, Timothy K. Starr, Dan Knights, Ran Blekhman

Biology: Faculty Publications and Other Works

Variation in the gut microbiome has been linked to colorectal cancer (CRC), as well as to host genetics. However, we do not know whether genetic mutations in CRC tumors interact with the structure and composition of the microbial communities surrounding the tumors, and if so, whether changes in the microbiome can be used as a predictor for tumor mutational status. Here, we characterized the association between CRC tumor mutational landscape and its proximal microbial communities by performing whole exome sequencing and microbiome profiling in tumors and normal colorectal tissue samples from the same patient. We find a significant association between …

Effect Of Oxygen-Limiting Tidal Conditions On Muscle Metabolism And Structure In The Giant Acorn Barnacle, Balanus Nubilus, Katie O. Grady

Master's Theses

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph …

Visualizing A Plant Cell, Rudaba R. Hasan

The Transdisciplinary STEAM+ Journal

Why visualizing science is important, especially as a school student.

Effects Of Cell Cycle Noise On Excitable Gene Circuits, Alan Veliz-Cuba, Chinmaya Gupta, Matthew R. Bennett, Krešimir Josić, William Ott

Mathematics Faculty Publications

We assess the impact of cell cycle noise on gene circuit dynamics. For bistable genetic switches and excitable circuits, we find that transitions between metastable states most likely occur just after cell division and that this concentration effect intensifies in the presence of transcriptional delay. We explain this concentration effect with a three-states stochastic model. For genetic oscillators, we quantify the temporal correlations between daughter cells induced by cell division. Temporal correlations must be captured properly in order to accurately quantify noise sources within gene networks.

The Subject Librarian Newsletter, Biology, Fall 2016, Sandy Avila

Libraries' Newsletters

No abstract provided.

The Roles Of Biotin In Candida Albicans Physiology, Nur Ras Aini Ahmad Hussin

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

Due to the increased number of immunocompromised patients, infections by Candida albicans have significantly increased in recent years. C. albicans transition from yeast to germ tubes is an essential factor for virulence. In this study we noted that Lee's medium, commonly used to induce filamentation, contained 500-fold more biotin than needed for growth. Thus, we investigated the effects of excess biotin on growth rate and filamentation by C. albicans in different media. At 37 °C, excess biotin (4 µM) enhanced germ tube formation (GTF) ca. 10-fold in both Lee's medium and a defined glucose proline medium, and ca. …

Oxidative Stress In Oocytes During Midprophase Induces Premature Loss Of Cohesion And Chromosome Segregation Errors, Adrienne T. Perkins, Thomas M. Das, Lauren C. Panzera, Sharon E. Bickel

Dartmouth Scholarship

In humans, errors in meiotic chromosome segregation that produce aneuploid gametes increase dramatically as women age, a phenomenon termed the "maternal age effect." During meiosis, cohesion between sister chromatids keeps recombinant homologs physically attached and premature loss of cohesion can lead to missegregation of homologs during meiosis I. A growing body of evidence suggests that meiotic cohesion deteriorates as oocytes age and contributes to the maternal age effect. One hallmark of aging cells is an increase in oxidative damage caused by reactive oxygen species (ROS). Therefore, increased oxidative damage in older oocytes may be one of the factors that leads …

Beryllium Nitrate Inhibits Fibroblast Migration To Disrupt Epimorphic Regeneration, Adam B. Cook, Ashley W. Seifert

Biology Faculty Publications

Epimorphic regeneration proceeds with or without formation of a blastema, as observed for the limb and skin, respectively. Inhibition of epimorphic regeneration provides a means to interrogate the cellular and molecular mechanisms that regulate it. In this study, we show that exposing amputated limbs to beryllium nitrate disrupts blastema formation and causes severe patterning defects in limb regeneration. In contrast, exposing full-thickness skin wounds to beryllium only causes a delay in skin regeneration. By transplanting full-thickness skin from ubiquitous GFP-expressing axolotls to wild-type hosts, we demonstrate that beryllium inhibits fibroblast migration during limb and skin regeneration in vivo. Moreover, …

Talin2-Mediated Traction Force Drives Matrix Degradation And Cell Invasion, Lei Qi, Naser Jafari, Xiang Li, Zaozao Chen, Liqing Li, Vesa P. Hytönen, Benjamin T. Goult, Chang-Guo Zhan, Cai Huang

Markey Cancer Center Faculty Publications

Talin binds to β-integrin tails to activate integrins, regulating cell migration, invasion and metastasis. There are two talin genes, TLN1 and TLN2, encoding talin1 and talin2, respectively. Talin1 regulates focal adhesion dynamics, cell migration and invasion, whereas the biological function of talin2 is not clear and, indeed, talin2 has been presumed to function redundantly with talin1. Here, we show that talin2 has a much stronger binding to β-integrin tails than talin1. Replacement of talin2 Ser339 with Cys significantly decreased its binding to β1-integrin tails to a level comparable to that of talin1. Talin2 localizes at invadopodia and is indispensable …

Receptor-Type Guanylyl Cyclase At 76c (Gyc76c) Regulates De Novo Lumen Formation During Drosophila Tracheal Development, Monn Monn Myat, Unisha Patel

Publications and Research

Lumen formation and maintenance are important for the development and function of essential organs such as the lung, kidney and vasculature. In the Drosophila embryonic trachea, lumena formde novo to connect the different tracheal branches into an interconnected network of tubes. Here, we identify a novel role for the receptor type guanylyl cyclase at 76C (Gyc76C) in de novo lumen formation in the Drosophila trachea.We show that in embryosmutant for gyc76C or its downsteam effector protein kinase G (PKG) 1, tracheal lumena are disconnected. Dorsal trunk (DT) cells of gyc76C mutant embryos migrate to contact each other and complete the …