Open Access. Powered by Scholars. Published by Universities.®

Cell Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Biology Faculty Publications

Discipline
Institution
Keyword
Publication Year

Articles 1 - 30 of 77

Full-Text Articles in Cell Biology

Characterization Of A Morphogenetic Furrow Specific Gal4 Driver In The Developing Drosophila Eye, Ankita Sarkar, Neha Gogia, Kevin Farley, Lydia C. Payton, Amit Singh Apr 2018

Characterization Of A Morphogenetic Furrow Specific Gal4 Driver In The Developing Drosophila Eye, Ankita Sarkar, Neha Gogia, Kevin Farley, Lydia C. Payton, Amit Singh

Biology Faculty Publications

The ability to express a gene of interest in a spatio-temporal manner using Gal4-UAS system has allowed the use of Drosophila model to study various biological phenomenon. During Drosophila eye development, a synchronous wave of differentiation called Morphogenetic furrow (MF) initiates at the posterior margin resulting in differentiation of retinal neurons. This synchronous differentiation is also observed in the differentiating retina of vertebrates. Since MF is highly dynamic, it can serve as an excellent model to study patterning and differentiation. However, there are not any Gal4 drivers available to observe the gain- of- function or loss- of- function of a ...


Tropical Herbivorous Phasmids, But Not Litter Snails, Alter Decomposition Rates By Modifying Litter Bacteria, Chelse M. Prather, Gary E. Belovsky, Sharon A. Cantrell, Grizelle Gonzalez Jan 2018

Tropical Herbivorous Phasmids, But Not Litter Snails, Alter Decomposition Rates By Modifying Litter Bacteria, Chelse M. Prather, Gary E. Belovsky, Sharon A. Cantrell, Grizelle Gonzalez

Biology Faculty Publications

Consumers can alter decomposition rates through both feces and selective feeding in many ecosystems, but these combined effects have seldom been examined in tropical ecosystems. Members of the detrital food web (litter-feeders or microbivores) should presumably have greater effects on decomposition than herbivores, members of the green food web. Using litterbag experiments within a field enclosure experiment, we determined the relative effects of common litter snails (Megalomastoma croceum) and herbivorous walking sticks (Lamponius portoricensis) on litter composition, decomposition rates, and microbes in a Puerto Rican rainforest, and whether consumer effects were altered by canopy cover presence. Although canopy presence did ...


The 'Pseudomonas Aeruginosa' Psl Polysaccharide Is A Social But Noncheatable Trait In Biofilms, Yasuhiko Irie, Aled E. Roberts, Kasper N. Kragh, Vernita D. Gordon, Jaime B. Hutchison, Rosalind J. Allen, Gavin Melaugh, Thomas Bjarnsholt, Stuart A. West, Stephen P. Diggle Jun 2017

The 'Pseudomonas Aeruginosa' Psl Polysaccharide Is A Social But Noncheatable Trait In Biofilms, Yasuhiko Irie, Aled E. Roberts, Kasper N. Kragh, Vernita D. Gordon, Jaime B. Hutchison, Rosalind J. Allen, Gavin Melaugh, Thomas Bjarnsholt, Stuart A. West, Stephen P. Diggle

Biology Faculty Publications

Extracellular polysaccharides are compounds secreted by microorganisms into the surrounding environment, and they are important for surface attachment and maintaining structural integrity within biofilms. The social nature of many extracellular polysaccharides remains unclear, and it has been suggested that they could function as either cooperative public goods or as traits that provide a competitive advantage. Here, we empirically tested the cooperative nature of the PSL polysaccharide, which is crucial for the formation of biofilms in Pseudomonas aeruginosa. We show that (i) PSL is not metabolically costly to produce; (ii) PSL provides populationlevel benefits in biofilms, for both growth and antibiotic ...


Macrophages Are Necessary For Epimorphic Regeneration In African Spiny Mice, Jennifer Simkin, Thomas R. Gawriluk, John C. Gensel, Ashley W. Seifert May 2017

Macrophages Are Necessary For Epimorphic Regeneration In African Spiny Mice, Jennifer Simkin, Thomas R. Gawriluk, John C. Gensel, Ashley W. Seifert

Biology Faculty Publications

How the immune system affects tissue regeneration is not well understood. In this study, we used an emerging mammalian model of epimorphic regeneration, the African spiny mouse, to examine cell-based inflammation and tested the hypothesis that macrophages are necessary for regeneration. By directly comparing inflammatory cell activation in a 4 mm ear injury during regeneration (Acomys cahirinus) and scarring (Mus musculus), we found that both species exhibited an acute inflammatory response, with scarring characterized by stronger myeloperoxidase activity. In contrast, ROS production was stronger and more persistent during regeneration. By depleting macrophages during injury, we demonstrate a functional requirement for ...


Characterization Of A New Oda3 Allele, Oda3-6, Defective In Assembly Of The Outer Dynein Arm-Docking Complex In Chlamydomonas Reinhardtii, Jason M. Brown, Matthew Mosley, Daniela Montes-Berrueta, Yuqing Hou, Fan Yang, Chasity Scarbrough, George B. Witman, Maureen Wirschell Mar 2017

Characterization Of A New Oda3 Allele, Oda3-6, Defective In Assembly Of The Outer Dynein Arm-Docking Complex In Chlamydomonas Reinhardtii, Jason M. Brown, Matthew Mosley, Daniela Montes-Berrueta, Yuqing Hou, Fan Yang, Chasity Scarbrough, George B. Witman, Maureen Wirschell

Biology Faculty Publications

We have used an insertional mutagenesis approach to generate new C. reinhardtii motility mutants. Of 56 mutants isolated, one is a new allele at the ODA3 locus, called oda3-6. Similar to the previously characterized oda3 alleles, oda3-6 has a slow-jerky swimming phenotype and reduced swimming speed. The oda3-6 mutant fails to assemble the outer dynein arm motor and outer dynein arm—docking complex (ODA-DC) in the ciliary axoneme due to an insertion in the 5’ end of the DCC1 gene, which encodes the DC1 subunit of the ODA-DC. Transformation of oda3-6 with the wild-type DCC1 gene rescues the mutant swimming ...


Evolutionary Adaptations Of Biofilms Infecting Cystic Fibrosis Lungs Promote Mechanical Toughness By Adjusting Polysaccharide Production, Kristin Kovach, Megan Davis-Fields, Yasuhiko Irie, Kanishk Jain, Shashvat Doorwar, Katherine Vuong, Numa Dhamani, Kishore Mohanty, Ahmed Touhami, Vernita D. Gordon Jan 2017

Evolutionary Adaptations Of Biofilms Infecting Cystic Fibrosis Lungs Promote Mechanical Toughness By Adjusting Polysaccharide Production, Kristin Kovach, Megan Davis-Fields, Yasuhiko Irie, Kanishk Jain, Shashvat Doorwar, Katherine Vuong, Numa Dhamani, Kishore Mohanty, Ahmed Touhami, Vernita D. Gordon

Biology Faculty Publications

Biofilms are communities of microbes embedded in a matrix of extracellular polymeric substances, largely polysaccharides. Multiple types of extracellular polymeric substances can be produced by a single bacterial strain. The distinct polymer components of biofilms are known to provide chemical protection, but little is known about how distinct extracellular polysaccharides may also protect biofilms against mechanical stresses such as shear or phagocytic engulfment. Decades-long infections of Pseudomonas. aeruginosa biofilms in the lungs of cystic fibrosis patients are natural models for studies of biofilm fitness under pressure from antibiotics and the immune system. In cystic fibrosis infections, production of the extracellular ...


An Undergraduate Cell Biology Lab: Western Blotting To Detect Proteins From Drosophila Eye, Neha Gogia, Ankita Sarkar, Amit Singh Jan 2017

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 electrophoresis ...


Real-Time Quantitative Pcr To Demonstrate Gene Expression In An Undergraduate Lab, Abijeet Singh Mehta, Amit Singh Jan 2017

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 ...


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 Dec 2016

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 ...


Loss Of Cell Adhesion Increases Tumorigenic Potential Of Polarity Deficient Scribble Mutant Cells, Indrayani Waghmare, Madhuri Kango-Singh Jun 2016

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 mechanism that regulates ...


Alzheimer's Disease: The Silver Tsunami Of The 21st Century, Ankita Sarkar, Madison Irwin, Aditi Singh, Matthew Riccetti, Amit Singh May 2016

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 ...


Shaping The Growth Behaviour Of Biofilms Initiated From Bacterial Aggregates, Gavin Melaugh, Jaime B. Hutchison, Kasper N. Kragh, Yasuhiko Irie, Aled E. L. Roberts, Thomas Bjarnsholt, Stephen P. Diggle, Vernita Gordon, Rosalind J. Allen Mar 2016

Shaping The Growth Behaviour Of Biofilms Initiated From Bacterial Aggregates, Gavin Melaugh, Jaime B. Hutchison, Kasper N. Kragh, Yasuhiko Irie, Aled E. L. Roberts, Thomas Bjarnsholt, Stephen P. Diggle, Vernita Gordon, Rosalind J. Allen

Biology Faculty Publications

Bacterial biofilms are usually assumed to originate from individual cells deposited on a surface. However, many biofilm-forming bacteria tend to aggregate in the planktonic phase so that it is possible that many natural and infectious biofilms originate wholly or partially from pre-formed cell aggregates. Here, we use agent-based computer simulations to investigate the role of pre-formed aggregates in biofilm development. Focusing on the initial shape the aggregate forms on the surface, we find that the degree of spreading of an aggregate on a surface can play an important role in determining its eventual fate during biofilm development. Specifically, initially spread ...


The Impact Of Oxygen On Bacterial Enteric Pathogens, Nathan Wallace, Ashley N. Zani, Elizabeth A. Abrams, Yvonne Sun Jan 2016

The Impact Of Oxygen On Bacterial Enteric Pathogens, Nathan Wallace, Ashley N. Zani, Elizabeth A. Abrams, Yvonne Sun

Biology Faculty Publications

Bacterial enteric pathogens are responsible for a tremendous amount of foodborne illnesses every year through the consumption of contaminated food products. During their transit from contaminated food sources to the host gastrointestinal tract, these pathogens are exposed and must adapt to fluctuating oxygen levels to successfully colonize the host and cause diseases. However, the majority of enteric infection research has been conducted under aerobic conditions. To raise awareness of the importance in understanding the impact of oxygen, or lack of oxygen, on enteric pathogenesis, we describe in this review the metabolic and physiological responses of nine bacterial enteric pathogens exposed ...


Drosophila Eye Model To Study Neuroprotective Role Of Creb Binding Protein (Cbp) In Alzheimer’S Disease, Timothy Cutler, Ankita Sarkar, Michael Moran, Andrew Steffensmeier, Oorvashi Roy Puli, Greg Mancini, Meghana Tare Sep 2015

Drosophila Eye Model To Study Neuroprotective Role Of Creb Binding Protein (Cbp) In Alzheimer’S Disease, Timothy Cutler, Ankita Sarkar, Michael Moran, Andrew Steffensmeier, Oorvashi Roy Puli, Greg Mancini, Meghana Tare

Biology Faculty Publications

Background: The progressive neurodegenerative disorder Alzheimer’s disease (AD) manifests as loss of cognitive functions, and finally leads to death of the affected individual. AD may result from accumulation of amyloid plaques. These amyloid plaques comprising of amyloid-beta 42 (Aβ42) polypeptides results from the improper cleavage of amyloid precursor protein (APP) in the brain. The Aβ42 plaques have been shown to disrupt the normal cellular processes and thereby trigger abnormal signaling which results in the death of neurons. However, the molecular-genetic mechanism(s) responsible for Aβ42 mediated neurodegeneration is yet to be fully understood.

Methodology/Principal Findings: We have utilized ...


The Cababc Operon Essential For Biofilm And Rugose Colony Development In Vibrio Vulnificus, Jin Hwan Park, Youmi Jo, Song Yee Jang, Haenaem Kwon, Yasuhiko Irie, Matthew R. Parsek, Myung Hee Kim, Sang Ho Choi Sep 2015

The Cababc Operon Essential For Biofilm And Rugose Colony Development In Vibrio Vulnificus, Jin Hwan Park, Youmi Jo, Song Yee Jang, Haenaem Kwon, Yasuhiko Irie, Matthew R. Parsek, Myung Hee Kim, Sang Ho Choi

Biology Faculty Publications

A transcriptome analysis identified Vibrio vulnificus cabABC genes which were preferentially expressed in biofilms. The cabABC genes were transcribed as a single operon. The cabA gene was induced by elevated 3′,5′-cyclic diguanylic acid (c-di-GMP) and encoded a calcium-binding protein CabA. Comparison of the biofilms produced by the cabA mutant and its parent strain JN111 in microtiter plates using crystal-violet staining demonstrated that CabA contributed to biofilm formation in a calcium-dependent manner under elevated c-di-GMP conditions. Genetic and biochemical analyses revealed that CabA was secreted to the cell exterior through functional CabB and CabC, distributed throughout the biofilm matrix ...


Beyond Bivariate Correlations: Three-Block Partial Least Squares Illustrated With Vegetation, Soil, And Topography, Daehyun Kim, Thomas J. Dewitt, César S. B. Costa, John A. Kupfer, Ryan W. Mcewan, J. Anthony Stallins Aug 2015

Beyond Bivariate Correlations: Three-Block Partial Least Squares Illustrated With Vegetation, Soil, And Topography, Daehyun Kim, Thomas J. Dewitt, César S. B. Costa, John A. Kupfer, Ryan W. Mcewan, J. Anthony Stallins

Biology Faculty Publications

Ecologists, particularly those engaged in biogeomorphic studies, often seek to connect data from three or more domains. Using three-block partial least squares regression, we present a procedure to quantify and define bi-variance and tri-variance of data blocks related to plant communities, their soil parameters, and topography. Bi-variance indicates the total amount of covariation between these three domains taken in pairs, whereas tri-variance refers to the common variance shared by all domains. We characterized relationships among three domains (plant communities, soil properties, topography) for a salt marsh, four coastal dunes, and two temperate forests spanning several regions in the world. We ...


Genetic Changes To A Transcriptional Silencer Element Confers Phenotypic Diversity Within And Between Drosophila Species, Winslow C. Johnson, Alison J. Ordway, Masayoshi Watada, Jonathan N. Pruitt, Thomas M. Williams, Mark Rebeiz Jun 2015

Genetic Changes To A Transcriptional Silencer Element Confers Phenotypic Diversity Within And Between Drosophila Species, Winslow C. Johnson, Alison J. Ordway, Masayoshi Watada, Jonathan N. Pruitt, Thomas M. Williams, Mark Rebeiz

Biology Faculty Publications

The modification of transcriptional regulation has become increasingly appreciated as a major contributor to morphological evolution. However, the role of negative-acting control elements (e.g. silencers) in generating morphological diversity has been generally overlooked relative to positive-acting “enhancer” elements. The highly variable body coloration patterns among Drosophilid insects represents a powerful model system in which the molecular alterations that underlie phenotypic diversity can be defined. In a survey of pigment phenotypes among geographically disparate Japanese populations of Drosophila auraria, we discovered a remarkable degree of variation in male-specific abdominal coloration. In testing the expression patterns of the major pigment-producing enzymes ...


The Hippo Pathway Effector Yki Downregulates Wg Signaling To Promote Retinal Differentiation In The Drosophila Eye, Erika Lynn Wittkorn, Ankita Sarkar, Kristine Garcia, Madhuri Kango-Singh, Amit Singh May 2015

The Hippo Pathway Effector Yki Downregulates Wg Signaling To Promote Retinal Differentiation In The Drosophila Eye, Erika Lynn Wittkorn, Ankita Sarkar, Kristine Garcia, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

The evolutionarily conserved Hippo signaling pathway is known to regulate cell proliferation and maintain tissue homeostasis during development. We found that activation of Yorkie (Yki), the effector of the Hippo signaling pathway, causes separable effects on growth and differentiation of theDrosophila eye. We present evidence supporting a role for Yki in suppressing eye fate by downregulation of the core retinal determination genes. Other upstream regulators of the Hippo pathway mediate this effect of Yki on retinal differentiation. Here, we show that, in the developing eye, Yki can prevent retinal differentiation by blocking morphogenetic furrow (MF) progression and R8 specification ...


Cell Type-Specific Responses To Wingless, Hedgehog And Decapentaplegic Are Essential For Patterning Early Eye-Antenna Disc In Drosophila, Jong-Hoon Won, Orkhon Tsogtbartarr, Wonseok Son, Amit Singh, Kwang-Wook Choi, Kyung-Ok Cho Apr 2015

Cell Type-Specific Responses To Wingless, Hedgehog And Decapentaplegic Are Essential For Patterning Early Eye-Antenna Disc In Drosophila, Jong-Hoon Won, Orkhon Tsogtbartarr, Wonseok Son, Amit Singh, Kwang-Wook Choi, Kyung-Ok Cho

Biology Faculty Publications

The Drosophila eye-antenna imaginal disc (ead) is a flattened sac of two-layered epithelia, from which most head structures are derived. Secreted morphogens like Wingless (Wg), Hedgehog (Hh), and Decapentaplegic (Dpp) are important for early patterning of ead, but the underlying mechanisms are still largely unknown. To understand how these morphogens function in the ead of early larval stages, we used wg-LacZ and dpp-Gal4 markers for the examination of wild-type and mutant eads. We found that the ead immediately after hatching was crescent-shaped with the Bolwig’s nerve at the ventral edge, suggesting that it consists of dorsal domain. In a ...


The Evolutionary Origination And Diversification Of A Dimorphic Gene Regulatory Network Through Parallel Innovations In Cis And Trans, Eric M. Camino, John C. Butts, Alison J. Ordway, Jordan E. Vellky, Mark Rebeiz, Thomas M. Williams Apr 2015

The Evolutionary Origination And Diversification Of A Dimorphic Gene Regulatory Network Through Parallel Innovations In Cis And Trans, Eric M. Camino, John C. Butts, Alison J. Ordway, Jordan E. Vellky, Mark Rebeiz, Thomas M. Williams

Biology Faculty Publications

The origination and diversification of morphological characteristics represents a key problem in understanding the evolution of development. Morphological traits result from gene regulatory networks (GRNs) that form a web of transcription factors, which regulate multiple cis-regulatory element (CRE) sequences to control the coordinated expression of differentiation genes. The formation and modification of GRNs must ultimately be understood at the level of individual regulatory linkages (i.e., transcription factor binding sites within CREs) that constitute the network. Here, we investigate how elements within a network originated and diversified to generate a broad range of abdominal pigmentation phenotypes among Sophophora fruit ...


Intercellular Cooperation And Competition In Brain Cancers: Lessons From Drosophila And Human Studies, Indrayani Waghmare, Austin Roebke, Mutsuko Minata, Madhuri Kango-Singh, Ichiro Nakano Nov 2014

Intercellular Cooperation And Competition In Brain Cancers: Lessons From Drosophila And Human Studies, Indrayani Waghmare, Austin Roebke, Mutsuko Minata, Madhuri Kango-Singh, Ichiro Nakano

Biology Faculty Publications

Glioblastoma (GBM) is a primary brain cancer with an extremely poor prognosis. GBM tumors contain heterogeneous cellular components, including a small subpopulation of tumor cells termed glioma stem cells (GSCs). GSCs are characterized as chemotherapy- and radiotherapy-resistant cells with prominent tumorigenic ability. Studies in Drosophila cancer models demonstrated that interclonal cooperation and signaling from apoptotic clones provokes aggressive growth of neighboring tumorigenic clones, via compensatory proliferation or apoptosis induced proliferation. Mechanistically, these aggressive tumors depend on activation of Jun-N-terminal kinase (upstream of c-JUN), and Drosophila Wnt (Wg) in the apoptotic clones. Consistent with these nonmammalian studies, data from several mammalian ...


Chip-Seq And Rna-Seq Reveal An Amrz-Mediated Mechanism For Cyclic Di-Gmp Synthesis And Biofilm Development By Pseudomonas Aeruginosa, Christopher J. Jones, David Newsom, Benjamin Kelly, Yasuhiko Irie, Laura K. Jennings, Binjie Xu, Dominique H. Limoli, Joe J. Harrison, Matthew R. Parsek, Peter White, Daniel J. Wozniak Mar 2014

Chip-Seq And Rna-Seq Reveal An Amrz-Mediated Mechanism For Cyclic Di-Gmp Synthesis And Biofilm Development By Pseudomonas Aeruginosa, Christopher J. Jones, David Newsom, Benjamin Kelly, Yasuhiko Irie, Laura K. Jennings, Binjie Xu, Dominique H. Limoli, Joe J. Harrison, Matthew R. Parsek, Peter White, Daniel J. Wozniak

Biology Faculty Publications

The transcription factor AmrZ regulates genes important for P. aeruginosa virulence, including type IV pili, extracellular polysaccharides, and the flagellum; however, the global effect of AmrZ on gene expression remains unknown, and therefore, AmrZ may directly regulate many additional genes that are crucial for infection. Compared to the wild type strain, a ΔamrZ mutant exhibits a rugose colony phenotype, which is commonly observed in variants that accumulate the intracellular second messenger cyclic diguanylate (c-di-GMP). Cyclic di-GMP is produced by diguanylate cyclases (DGC) and degraded by phosphodiesterases (PDE). We hypothesized that AmrZ limits the intracellular accumulation of c-di-GMP through transcriptional repression ...


Novel Neuroprotective Function Of Apical-Basal Polarity Genecrumbs In Amyloid Beta 42 (Aβ42) Mediated Neurodegeneration, Andrew Steffensmeier, Meghana Tare, Oorvashi Roy Puli, Rohan Modi, Jaison Nainaparampil, Madhuri Kango-Singh, Amit Singh Nov 2013

Novel Neuroprotective Function Of Apical-Basal Polarity Genecrumbs In Amyloid Beta 42 (Aβ42) Mediated Neurodegeneration, Andrew Steffensmeier, Meghana Tare, Oorvashi Roy Puli, Rohan Modi, Jaison Nainaparampil, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Alzheimer's disease (AD, OMIM: 104300), a progressive neurodegenerative disorder with no cure to date, is caused by the generation of amyloid-beta-42 (Aβ42) aggregates that trigger neuronal cell death by unknown mechanism(s). We have developed a transgenic Drosophilaeye model where misexpression of human Aβ42 results in AD-like neuropathology in the neural retina. We have identified an apical-basal polarity gene crumbs (crb) as a genetic modifier of Aβ42-mediated-neuropathology. Misexpression of Aβ42 caused upregulation of Crb expression, whereas downregulation of Crb either by RNAi or null allele approach rescued the Aβ42-mediated-neurodegeneration. Co-expression of full length Crb with Aβ42 increased severity ...


Recurrent Modification Of A Conserved Cis-Regulatory Element Underlies Fruit Fly Pigmentation Diversity, William A. Rogers, Joseph R. Salomone, David J. Tacy, Eric M. Camino, Kristen A. Davis, Mark Rebeiz, Thomas M. Williams Aug 2013

Recurrent Modification Of A Conserved Cis-Regulatory Element Underlies Fruit Fly Pigmentation Diversity, William A. Rogers, Joseph R. Salomone, David J. Tacy, Eric M. Camino, Kristen A. Davis, Mark Rebeiz, Thomas M. Williams

Biology Faculty Publications

The development of morphological traits occurs through the collective action of networks of genes connected at the level of gene expression. As any node in a network may be a target of evolutionary change, the recurrent targeting of the same node would indicate that the path of evolution is biased for the relevant trait and network. Although examples of parallel evolution have implicated recurrent modification of the same gene and cis-regulatory element (CRE), little is known about the mutational and molecular paths of parallel CRE evolution. InDrosophila melanogaster fruit flies, the Bric-à-brac (Bab) transcription factors control the development ...


Germline Transgenic Methods For Tracking Cells And Testing Gene Function During Regeneration In The Axolotl, Shahryar Khattak, Maritta Schuez, Tobias Richter, Dunja Knapp, Saori L. Haigo, Tatiana Sandoval-Guzmán, Kristyna Hradlikova, Annett Duemmler, Ryan R. Kerney, Elly M. Tanaka Jun 2013

Germline Transgenic Methods For Tracking Cells And Testing Gene Function During Regeneration In The Axolotl, Shahryar Khattak, Maritta Schuez, Tobias Richter, Dunja Knapp, Saori L. Haigo, Tatiana Sandoval-Guzmán, Kristyna Hradlikova, Annett Duemmler, Ryan R. Kerney, Elly M. Tanaka

Biology Faculty Publications

The salamander is the only tetrapod that regenerates complex body structures throughout life. Deciphering the underlying molecular processes of regeneration is fundamental for regenerative medicine and developmental biology, but the model organism had limited tools for molecular analysis. We describe a comprehensive set of germline transgenic strains in the laboratory-bred salamander Ambystoma mexicanum(axolotl) that open up the cellular and molecular genetic dissection of regeneration. We demonstrate tissue-dependent control of gene expression in nerve, Schwann cells, oligodendrocytes, muscle, epidermis, and cartilage. Furthermore, we demonstrate the use of tamoxifen-induced Cre/loxP-mediated recombination to indelibly mark different cell types. Finally, we ...


Use Of Image Cytometry For Quantification Of Pathogenic Fungi In Association With Host Cells, Charlotte A. Berkes, Leo Li-Ying Chan, Alisha Wilkinson, Benjamin Paradis Jun 2013

Use Of Image Cytometry For Quantification Of Pathogenic Fungi In Association With Host Cells, Charlotte A. Berkes, Leo Li-Ying Chan, Alisha Wilkinson, Benjamin Paradis

Biology Faculty Publications

Studies of the cellular pathogenesis mechanisms of pathogenic yeasts such as Candida albicans, Histoplasma capsulatum, and Cryptococcus neoformans commonly employ infection of mammalian hosts or host cells (i.e. macrophages) followed by yeast quantification using colony forming unit analysis or flow cytometry. While colony forming unit enumeration has been the most commonly used method in the field, this technique has disadvantages and limitations, including slow growth of some fungal species on solid media and low and/or variable plating efficiencies, which is of particular concern when comparing growth of wild-type and mutant strains. Flow cytometry can provide rapid quantitative information ...


Scribble Acts In The Drosophila Fat-Hippo Pathway To Regulate Warts Activity, Shilpi Verghese, Indrayani Waghmare, Hailey Kwon, Katelin Hanes, Madhuri Kango-Singh Nov 2012

Scribble Acts In The Drosophila Fat-Hippo Pathway To Regulate Warts Activity, Shilpi Verghese, Indrayani Waghmare, Hailey Kwon, Katelin Hanes, Madhuri Kango-Singh

Biology Faculty Publications

Epithelial cells are the major cell-type for all organs in multicellular organisms. In order to achieve correct organ size, epithelial tissues need mechanisms that limit their proliferation, and protect tissues from damage caused by defective epithelial cells. Recently, the Hippo signaling pathway has emerged as a major mechanism that orchestrates epithelial development. Hippo signaling is required for cells to stop proliferation as in the absence of Hippo signaling tissues continue to proliferate and produce overgrown organs or tumors. Studies in Drosophila have led the way in providing a framework for how Hippo alters the pattern of gene transcription in target ...


Fluorescence-Based Reporter For Gauging Cyclic Di-Gmp Levels In Pseudomonas Aeruginosa, Morten T. Rybtke, Bradley R. Borlee, Keiji Murakami, Yasuhiko Irie, Morten Hentzer, Thomas E. Nielsen, Michael Givskov, Matthew R. Parsek, Tim Tolker-Nielsen May 2012

Fluorescence-Based Reporter For Gauging Cyclic Di-Gmp Levels In Pseudomonas Aeruginosa, Morten T. Rybtke, Bradley R. Borlee, Keiji Murakami, Yasuhiko Irie, Morten Hentzer, Thomas E. Nielsen, Michael Givskov, Matthew R. Parsek, Tim Tolker-Nielsen

Biology Faculty Publications

The increased tolerance toward the host immune system and antibiotics displayed by biofilm-forming Pseudomonas aeruginosa and other bacteria in chronic infections such as cystic fibrosis bronchopneumonia is of major concern. Targeting of biofilm formation is believed to be a key aspect in the development of novel antipathogenic drugs that can augment the effect of classic antibiotics by decreasing antimicrobial tolerance. The second messenger cyclic di-GMP is a positive regulator of biofilm formation, and cyclic di-GMP signaling is now regarded as a potential target for the development of antipathogenic compounds. Here we describe the development of fluorescent monitors that can gauge ...


Neurodegeneration - A Means To An End, Amit Singh Apr 2012

Neurodegeneration - A Means To An End, Amit Singh

Biology Faculty Publications

Cell death, a global phenomenon found throughout the animal kingdom, is a mechanism to maintain tissue homeostasis and for adaptation to changes in the environment [1,2]. Millions of cells die in our body daily- they succumb to stress and commit suicide by a mechanism referred to as cell death or apoptosis [2-4]. Under normal conditions cells are continuously replaced by new cells from the stemor progenitor- cells. For example, an optimum balance in shedding of dead cells from the skin and their replenishment by new ones maintain our health and hygiene. In this context, apoptosis is a mechanism to ...


Tumor Suppression By Cell Competition Through Regulation Of The Hippo Pathway, Chiao-Lin Chen, Molly C. Schroeder, Madhuri Kango-Singh, Chunyao Tao, Georg Halder Jan 2012

Tumor Suppression By Cell Competition Through Regulation Of The Hippo Pathway, Chiao-Lin Chen, Molly C. Schroeder, Madhuri Kango-Singh, Chunyao Tao, Georg Halder

Biology Faculty Publications

Homeostatic mechanisms can eliminate abnormal cells to prevent diseases such as cancer. However, the underlying mechanisms of this surveillance are poorly understood. Here we investigated how clones of cells mutant for the neoplastic tumor suppressor gene scribble (scrib) are eliminated from Drosophila imaginal discs. When all cells in imaginal discs are mutant for scrib, they hyperactivate the Hippo pathway effector Yorkie (Yki), which drives growth of the discs into large neoplastic masses. Strikingly, when discs also contain normal cells, the scrib− cells do not overproliferate and eventually undergo apoptosis through JNK-dependent mechanisms. However, induction of apoptosis does not explain how ...