Shared Visual Attention and Memory Systems in the Drosophila Brain

Background: Selective attention and memory seem to be related in human experience. This appears to be the case as well in simple model organisms such as the fly Drosophila melanogaster. Mutations affecting olfactory and visual memory formation in Drosophila, such as in dunce and rutabaga, also affect short-term visual processes relevant to selective attention. In particular, increased optomotor responsiveness appears to be predictive of visual attention defects in these mutants. Methodology/Principal Findings: To further explore the possible overlap between memory and visual attention systems in the fly brain, we screened a panel of 36 olfactory long term memory (LTM) mutants for visual attention-like defects using an optomotor maze paradigm. Three of these mutants yielded high dunce-like optomotor responsiveness. We characterized these three strains by examining their visual distraction in the maze, their visual learning capabilities, and their brain activity responses to visual novelty. We found that one of these mutants, D0067, was almost completely identical to dunce for all measures, while another, D0264, was more like wild type. Exploiting the fact that the LTM mutants are also Gal4 enhancer traps, we explored the sufficiency for the cells subserved by these elements to rescue dunce attention defects and found overlap at the level of the mushroom bodies. Finally, we demonstrate that control of synaptic function in these Gal4 expressing cells specifically modulates a 20-30 Hz local field potential associated with attention-like effects in the fly brain. Conclusions/Significance: Our study uncovers genetic and neuroanatomical systems in the fly brain affecting both visual attention and odor memory phenotypes. A common component to these systems appears to be the mushroom bodies, brain structures which have been traditionally associated with odor learning but which we propose might be also involved in generating oscillatory brain activity required for attention-like processes in the fly brain

High resolution time series reveals cohesive but short-lived communities in coastal plankton

© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nature Communications 9 (2018): 266, doi:10.1038/s41467-017-02571-4.Because microbial plankton in the ocean comprise diverse bacteria, algae, and protists that are subject to environmental forcing on multiple spatial and temporal scales, a fundamental open question is to what extent these organisms form ecologically cohesive communities. Here we show that although all taxa undergo large, near daily fluctuations in abundance, microbial plankton are organized into clearly defined communities whose turnover is rapid and sharp. We analyze a time series of 93 consecutive days of coastal plankton using a technique that allows inference of communities as modular units of interacting taxa by determining positive and negative correlations at different temporal frequencies. This approach shows both coordinated population expansions that demarcate community boundaries and high frequency of positive and negative associations among populations within communities. Our analysis thus highlights that the environmental variability of the coastal ocean is mirrored in sharp transitions of defined but ephemeral communities of organisms.This work was supported by grants from the U.S. National Science Foundation (OCE-1441943) to M.F.P. and the U.S. Department of Energy (DE-SC0008743) to M.F.P. and E.J.A. A.M.M.-P. was partially supported by the Ramon Areces foundation through a postdoctoral fellowship. D.J.M. was supported by the U.S. National Science Foundation (OCE-1314642) and National Institute of Environmental Health Sciences (1P01ES021923-01) through the Woods Hole Center for Oceans and Human Health

The Lantern Vol. 70, No. 2, Spring 2003

• To the Automobile Owners of the Fine State of New Jersey • Topless • Lame Foot • Rosary Apologia • Alias • So Luscious • Dec 12 02 • Climbing • On Susannah in the Morning • Statistics • A Thursday in February • Breaking Blue • Leaves on my Tongue • The Bread They Mistook for a Kiss • The Process • Home is Where the Hershey\u27s is • Rock the Boat • The Splittinghttps://digitalcommons.ursinus.edu/lantern/1162/thumbnail.jp

Lrg1 Regulates β (1, 3)-Glucan Masking in Candida albicans through the Cek1 MAP Kinase Pathway

Candida albicans is among the most prevalent opportunistic human fungal pathogens. The ability to mask the immunogenic polysaccharide β (1,3)-glucan from immune detection via a layer of mannosylated proteins is a key virulence factor of C. albicans. We previously reported that hyperactivation of the Cek1 mitogen-activated protein (MAP) kinase pathway promotes β (1,3)-glucan exposure. In this communication, we report a novel upstream regulator of Cek1 activation and characterize the impact of Cek1 activity on fungal virulence. Lrg1 encodes a GTPase-activating protein (GAP) that has been suggested to inhibit the GTPase Rho1. We found that disruption of LRG1 causes Cek1 hyperactivation and β (1,3)-glucan unmasking. However, when GTPase activation was measured for a panel of GTPases, the lrg1ΔΔ mutant exhibited increased activation of Cdc42 and Ras1 but not Rho1 or Rac1. Unmasking and Cek1 activation in the lrg1ΔΔ mutant can be blocked by inhibition of the Ste11 MAP kinase kinase kinase (MAPKKK), indicating that the lrg1ΔΔ mutant acts through the canonical Cek1 MAP kinase cascade. In order to determine how Cek1 hyperactivation specifically impacts virulence, a doxycycline-repressible hyperactive STE11ΔN467 allele was expressed in C. albicans. In the absence of doxycycline, this allele overexpressed STE11ΔN467, which induced production of proinflammatory tumor necrosis factor alpha (TNF-α) from murine macrophages. This in vitrophenotype correlates with decreased colonization and virulence in a mouse model of systemic infection. The mechanism by which Ste11ΔN467 causes unmasking was explored with RNA sequencing (RNA-Seq) analysis. Overexpression of Ste11ΔN467 caused upregulation of the Cph1 transcription factor and of a group of cell wall-modifying proteins which are predicted to impact cell wall architecture

The Lantern Vol. 70, No. 1, Fall 2002

• (For Z) • Little Sister • Eulogy to Her Son, Dead at 22 • Tuesday • 7 Couplets for Drawing Genevieve • Diner Reflection • We Swam. We Made Sand Castles. • His Lips Were Figure Fitting • Public Transportation • Pop Culture • Running the Ridge • Like a Sunflower • Snooze • Match • Behavioral Correctional Facility of Santa Fe... • The Cellarhttps://digitalcommons.ursinus.edu/lantern/1161/thumbnail.jp

Essential Gene Identification and Drug Target Prioritization in Aspergillus fumigatus

Aspergillus fumigatus is the most prevalent airborne filamentous fungal pathogen in humans, causing severe and often fatal invasive infections in immunocompromised patients. Currently available antifungal drugs to treat invasive aspergillosis have limited modes of action, and few are safe and effective. To identify and prioritize antifungal drug targets, we have developed a conditional promoter replacement (CPR) strategy using the nitrogen-regulated A. fumigatus NiiA promoter (pNiiA). The gene essentiality for 35 A. fumigatus genes was directly demonstrated by this pNiiA-CPR strategy from a set of 54 genes representing broad biological functions whose orthologs are confirmed to be essential for growth in Candida albicans and Saccharomyces cerevisiae. Extending this approach, we show that the ERG11 gene family (ERG11A and ERG11B) is essential in A. fumigatus despite neither member being essential individually. In addition, we demonstrate the pNiiA-CPR strategy is suitable for in vivo phenotypic analyses, as a number of conditional mutants, including an ERG11 double mutant (erg11BΔ, pNiiA-ERG11A), failed to establish a terminal infection in an immunocompromised mouse model of systemic aspergillosis. Collectively, the pNiiA-CPR strategy enables a rapid and reliable means to directly identify, phenotypically characterize, and facilitate target-based whole cell assays to screen A. fumigatus essential genes for cognate antifungal inhibitors

The Lantern Vol. 71, No. 2, Spring 2004

• Football Captain • Grass Blades • Identity Theft • Her Shoulders • Doing 100 • Watching the • Fifteen Lines for Five • Plague • On the Occasion of Kissing You Less Than I Used To • Decomposey • Broomhandles • Just a Minute • War of the Words • Seguidille • At the End of One\u27s Rope • The Ride and Joe • I Want Soft Curls • Broken • Stories of a Hypochondriac • The TV is in Jail & My Mom is the Wardenhttps://digitalcommons.ursinus.edu/lantern/1164/thumbnail.jp

The Lantern Vol. 71, No. 1, Fall 2003

• Lights of Venice • Portrait • Switzerland • Drunken • Revel Writing • Nectarines • Shifting Gears • Stogie • Reflect • In the Key of Fuchsia Minor • Jarring • Sissy • Mongols vs. Amish: X-Treme Culture Clash • Holding On • The Bethany • Creekside • The Real Thing • On Being Alone and Other Pleasures • Forced Entry • The Case of Beauty: Aesthetics of Distancehttps://digitalcommons.ursinus.edu/lantern/1163/thumbnail.jp

The Lantern Vol. 69, No. 2, Spring 2002

• What was Said in the Court of Riong • Bailan Pies (Dancing Feet) • Canard • Vernacular City • Saturday Night Motorcycles • The Muse • I Stuffed my Face in the Herbs • Jacob\u27s Nightingale • At Tracey\u27s • Ona Time, a Rhym-mer • For Yo Yo Ma\u27s Encore • Two Minutes from Earl\u27s Court Tube Station • For Two • Bald • This Year\u27s Love • The Dimmer Switch • Tickertape • Imaginary Highway • First Kiss and Related Terrors • Hairball • His Hobbies • Spaghetti Dinnerhttps://digitalcommons.ursinus.edu/lantern/1160/thumbnail.jp