Cell and Developmental Biology Commons^™

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 …

48839 (Gmr19b04), Neha Gogia, Ankita Sarkar, Amit Singh

Dpp Enhancer Sequences Utilized in GMR Line

dpp enhancer - 48839

• Id - GMR19B04,
• Location - 2L:2432214,2435785
• Base pairs – 3571 bp

47472 (Gmr16g02), Neha Gogia, Ankita Sarkar, Amit Singh

Dpp Enhancer Sequences Utilized in GMR Line

dpp enhancer - 47472

• Id - GMR16G02
• Location 2L:2425041, 2428154
• Base pairs – 3113 bp

48770 (Gmr17e04), Neha Gogia, Ankita Sarkar, Amit Singh

Dpp Enhancer Sequences Utilized in GMR Line

dpp enhancer - 48770

• Id - GMR17E04
• Location 2L: 2428913..2432834
• Base pairs – 3921 bp

45833 (Gmr19d09), Neha Gogia, Ankita Sarkar, Amit Singh

Dpp Enhancer Sequences Utilized in GMR Line

dpp enhancer - 45833

• Id - GMR19D09
• Location - 2L:2435128,2438996
• Base pairs – 3868 bp

48784 (Gmr17g08), Neha Gogia, Ankita Sarkar, Amit Singh

Dpp Enhancer Sequences Utilized in GMR Line

dpp enhancer - 48784

• Id - GMR 17G08
• Location 2L:2450278,2451074
• Base pairs – 796 bp

45437 (Gmr18b08), Neha Gogia, Ankita Sarkar, Amit Singh

Dpp Enhancer Sequences Utilized in GMR Line

dpp enhancer - 45437

• Id - GMR18B08
• Location - 2L:2455899,2457734
• Base pairs – 1835 bp

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 …

45442 (Gmr18d08), Neha Gogia, Ankita Sarkar, Amit Singh

Dpp Enhancer Sequences Utilized in GMR Line

dpp enhancer - 45442

• Id - GMR 18D08
• Location - 2L:2446783,2449086
• Base pairs – 2303 bp

49283 (Gmr19c03), Neha Gogia, Ankita Sarkar, Amit Singh

Dpp Enhancer Sequences Utilized in GMR Line

dpp enhancer - 49283

• Id - GMR19C03
• Location - 2L:2440970,2444735
• Base pairs – 3765 bp

Prospective Study Of The Feasibility Of Point-Of-Care Testing Strategy For Carbapenem-Resistant Organism Detection, Rahul Pannala, Bruce Baldwin, Vijay Aluru, Thomas E. Grys, Jordan Holmes, Laurence J. Miller, M. Edwyn Harrison, Cuong C. Nguyen, Fred C. Tenover, David Persing, Douglas O. Faigel

Biology Faculty Publications

Background/aims: In an investigator-initiated, prospective study, we evaluated the feasibility of a five-gene sequence point-of-care (POC) testing strategy (Xpert CARBA-R Assay, Cepheid Inc., Sunnyvale, CA, USA), compared to reference laboratory PCR (48 – 72 hours turnaround time, two gene sequences), in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) and in a hospital outbreak investigation.

Methods: After informed consent, patients undergoing ERCP (September 2015 – April 2016, n = 191) at Mayo Clinic and potential hospital contacts (n = 9) of an index carbapenem-resistant organism (CRO)-positive inpatient were included. Two rectal swabs, one each for reference and POC assays were obtained. The …

Range Expansion And The Origin Of Usa300 North American Epidemic Methicillin-Resistant Staphylococcus Aureus, Lavanya Challagundla, Isabella A. Tickler, Xavier Didelot, David C. Coleman, Anna C. Shore, Geoffrey W. Coombs, Daniel O. Sordelli, Eric L. Brown, Robert Skov, Anders Rhod Larsen, Jinnethe Reyes, Iraida E. Robledo, Guillermo J. Vazquez, Paul Rivera, Paul D. Fey, Kurt Stevenson, Shu-Hua Wang, Barry N. Kreiswirth, Jose R. Mediavilla, Cesar A. Arias, Paul J. Planet, Rathel L. Nolan, Fred C. Tenover, Richard V. Goering, D. Ashley Robinson

Biology Faculty Publications

The USA300 North American epidemic (USA300-NAE) clone of methicillin-resistant Staphylococcus aureus has caused a wave of severe skin and soft tissue infections in the United States since it emerged in the early 2000s, but its geographic origin is obscure. Here we use the population genomic signatures expected from the serial founder effects of a geographic range expansion to infer the origin of USA300-NAE and identify polymorphisms associated with its spread. Genome sequences from 357 isolates from 22 U.S. states and territories and seven other countries are compared. We observe two significant signatures of range expansion, including decreases in genetic diversity …

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 …

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

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, …

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, …

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.

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 …

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 …

Drosophila Models To Investigate The Role Of Regulation Of Cell Death In Development And Cancer, Anam Hussain

Honors Theses

Cell death is of key importance in maintaining health and normal development. In cancer, cell death is improperly controlled provoking uncontrolled proliferation of cells, which results in severe harm to the body. The Hippo pathway is an identified pathway in Drosophila melanogaster that is involved with regulating the different mechanisms of survival and proliferation within the cells. It is known to interact with a gene known as Dronc that is a key participant in the cell death pathway of apoptosis. Previous work has shown how the loss of certain caspases, which are cysteine proteases, is linked with cell survival. My …

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

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

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 Gal4/UAS system to …

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, and produced …

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

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

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. …

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 flies. …

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 subsequent …