Cell Biology Commons^™

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 …

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 …

Expression And Regulatory Effects On Cancer Cell Behavior Of Nell1 And Nell2 In Human Renal Cell Carcinoma, Ritsuko Nakamura, Takeru Oyama, Ryosuke Tajiri, Atsushi Mizokami, Mikiko Namiki, Masaru Nakamoto, Akishi Ooi

Biology Faculty Publications

Neural epidermal growth factor-like like (NELL) 1 and 2 constitute a family of multimeric and multimodular extracellular glycoproteins. Although the osteogenic effects of NELL1 and functions of NELL2 in neural development have been reported, their expression and functions in cancer are largely unknown. In this study, we examined expression of NELL1 and NELL2 in renal cell carcinoma (RCC) using clinical specimens and cell lines. We show that, whereas NELL1 and NELL2 proteins are strongly expressed in renal tubules in non-cancerous areas of RCC specimens, their expression is significantly downregulated in cancerous areas. Silencing of NELL1 and NELL2 mRNA expression was …

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

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 …

Direct-To-Consumer Genetic Testing In The College Classroom: Knowledge, Attitudes, And Concerns Of Introductory Biology Students, Nicanor Austriaco

Biology Faculty Publications

Pioneered by companies like 23andMe.com, deCODEme.com, and Navigenics.com, direct-to-consumer genetic testing refers to genetic tests that are marketed directly to consumers via television, print media, or the Internet. This kind of testing provides access to a customer’s genetic information without necessarily involving either a medical health care professional or a genetic counselor in the process. In recent years, a course offered to medical and graduate students at Stanford University has included an option for students to undergo personal genotyping, raising the possibility that direct-to-consumer genetic testing could also be incorporated into undergraduate biology courses to enhance student learning. In this …

Deletion Of Aif1 But Not Of Yca1/Mca1 Protects Saccharomyces Cerevisiae And Candida Albicans Cells From Caspofungin-Induced Programmed Cell Death, Nicanor Austriaco, Christopher Chin, Faith Donaghey, Kathrine Helming, Morgan Mccarthy, Stephen Rogers

Biology Faculty Publications

Caspofungin was the first member of a new class of antifungals called echinocandins to be approved by a drug regulatory authority. Like the other echinocandins, caspofungin blocks the synthesis of β(1,3)-D-glucan of the fungal cell wall by inhibiting the enzyme, β(1,3)-D-glucan synthase. Loss of β(1,3)-D-glucan leads to osmotic instability and cell death. However, the precise mechanism of cell death associated with the cytotoxicity of caspofungin was unclear. We now provide evidence that Saccharomyces cerevisiae cells cultured in media containing caspofungin manifest the classical hallmarks of programmed cell death (PCD) in yeast, including the generation of reactive oxygen species (ROS), the …

Nel Positively Regulates The Genesis Of Retinal Ganglion Cells By Promoting Their Differentiation And Survival During Development, Chizu Nakamoto, Soh-Leh Kuan, Amy Findlay, Elaine Durward, Zhufeng Ouyang, Masaru Nakamoto, Ewa Zakrewska, Takuma Endo

Biology Faculty Publications

For correct functioning of the nervous system, the appropriate number and complement of neuronal cell types must be produced during development. However, the molecular mechanisms that regulate the production of individual classes of neurons are poorly understood. In this study, we investigate the function of the thrombospondin-1–like glycoprotein, Nel (neural epidermal growth factor [EGF]-like), in the generation of retinal ganglion cells (RGCs) in chicks. During eye development, Nel is strongly expressed in the presumptive retinal pigment epithelium and RGCs. Nel overexpression in the developing retina by in ovo electroporation increases the number of RGCs, whereas the number of displaced amacrine …

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 of Aβ42-mediated-neurodegeneration, …

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

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 inducibly …

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 regarding yeast …

Long-Term Data For Endemic Frog Genera Reveal Potential Conservation Crisis In The Bale Mountains, Ethiopia, David J. Gower, Roman K. Aberra, Silvia Schwaller, Malcolm J. Largen, Ben Collen, Stephen Spawls, Michele Menegon, Breda M. Zimkus, Rafael O. De Sá, Et Al.

Biology Faculty Publications

Populations of many frogs have declined alarmingly in recent years, placing nearly one third of the > 6,000 species under threat of extinction. Declines have been attributed largely to habitat loss, environmental degradation and/or infectious diseases such as chytridiomycosis. Many frogs undergo dramatic natural population fluctuations such that long-term data are required to determine population trends without undue influence of stochastic factors. We present long-term quantitative data (individuals encountered per person hour of searching) for four monotypic frog genera endemic to an Afromontane region of exceptional importance but growing conservation concern: one endemic to the Ethiopian highlands (Spinophrynoides osgoodi) and three …

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 …

Rapid Range Expansion In The Great Plains Narrow-Mouthed Toad (Gastrophryne Olivacea) And A Revised Taxonomy For North American Microhylids, Jeffrey W. Streicher, Christian L. Cox, Jonathan A. Campbell, Eric N. Smith, Rafael O. De Sá

Biology Faculty Publications

We investigated genetic variation within the Great Plains narrow-mouthed toad, Gastrophryne olivacea, across its geographic range in the United States and Mexico. An analysis of mitochondrial DNA (mtDNA) from 105 frogs revealed remarkably low levels of genetic diversity in individuals inhabiting the central United States and northern Mexico. We found that this widespread matrilineal lineage is divergent (ca. 2% in mtDNA) from haplotypes that originate from the western United States and western coast of Mexico. Using a dataset that included all five species of Gastrophryne and both species of the closely related genus Hypopachus, we investigated the phylogenetic …

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

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 eliminate …

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 …

Structure-Function Analysis Of Nel, A Thrombospondin-1-Like Glycoprotein Involved In Neural Development And Functions, Masaru Nakamoto

Biology Faculty Publications

Nel (neural epidermal growth factor (EGF)-like molecule) is a multimeric, multimodular extracellular glycoprotein with heparin-binding activity and structural similarities to thrombospondin-1. Nel is predominantly expressed in the nervous system and has been implicated in neuronal proliferation and differentiation, retinal axon guidance, synaptic functions, and spatial learning. The Nel protein contains an N-terminal thrombospondin-1 (TSP-N) domain, five cysteine-rich domains, and six EGF-like domains. However, little is known about the functions of specific domains of the Nel protein. In this study, we have performed structure-function analysis of Nel, by using a series of expression constructs for different regions of the Nel protein. …

Protein Trap Lines Of Drosophila To Demonstrate Spatio-Temporal Localization Of Proteins In An Undergraduate Lab, Oorvashi Roy Puli, Amit Singh

Biology Faculty Publications

The objective of this teaching note is to generate a laboratory exercise, which allows students to get a hands-on experience of a cell biology technique. The short duration of the laboratory classes is the biggest challenge with the development of a cell biology lab for an undergraduate curriculum. Therefore, it is necessary to design a laboratory exercise that enables the students to carry out cell biological assays in the desired time. This laboratory exercise focuses on tracking protein expression levels along a spatial (space) and temporal (time) axis in developing Drosophila melanogaster organ primordium. Here we use the protein trap …

Quantitative Comparison Of Cis-Regulatory Element (Cre) Activities In Transgenic Drosophila Melanogaster, William A. Rogers, Thomas M. Williams

Biology Faculty Publications

Gene expression patterns are specified by cis-regulatory element (CRE) sequences, which are also called enhancers or cis-regulatory modules. A typical CRE possesses an arrangement of binding sites for several transcription factor proteins that confer a regulatory logic specifying when, where, and at what level the regulated gene(s) is expressed. The full set of CREs within an animal genome encodes the organism′s program for development¹, and empirical as well as theoretical studies indicate that mutations in CREs played a prominent role in morphological evolution^2-4. Moreover, human genome wide association studies indicate that genetic variation in CREs …