Digital Commons Network^™

Ablation Of Sam50 Is Associated With Fragmentation And Alterations In Metabolism In Murine And Human Myotubes, Bryanna Shao, Mason Killion, Ashton Oliver, Chia Vang, Faben Zeleke, Kit Neikirk, Zer Vue, Edgar Garza‐Lopez, Jian‐Qiang Shao, Margaret Mungai, Jacob Lam, Qiana Williams, Christopher T. Altamura, Aaron Whiteside, Kinuthia Kabugi, Jessica Mckenzie, Maria Ezedimma, Han Le, Alice Koh, Estevão Scudese, Larry Vang, Andrea G. Marshall, Amber Crabtree, Janelle I. Tanghal, Dominique Stephens, Ho‐Jin Koh, Brenita C. Jenkins, Sandra A. Murray, Anthonya T. Cooper, Clintoria Williams, Steven M. Damo10 M. Damo, Melanie R. Mcreynolds, Jennifer A. Gaddy Gaddy, Celestine N. Wanjalla, Heather K. Beasley, Antentor Hinton Jr.

Biology Faculty Research

The sorting and assembly machinery (SAM) Complex is responsible for assembling β‐barrel proteins in the mitochondrial membrane. Comprising three subunits, Sam35, Sam37, and Sam50, the SAM complex connects the inner and outer mitochondrial membranes by interacting with the mitochondrial contact site and cristae organizing system complex. Sam50, in particular, stabilizes the mitochondrial intermembrane space

bridging (MIB) complex, which is crucial for protein transport, respiratory chain complex assembly, and regulation of cristae integrity. While the role of Sam50 in mitochondrial structure and metabolism in skeletal muscle remains unclear, this study aims to investigate its impact. Serial block‐face‐scanning electron microscopy and computer‐assisted …

Impacts Of Climate Change And Agricultural Practices On Nitrogen Processes, Genes, And Soil Nitrous Oxide Emissions: A Quantitative Review Of Meta-Analyses, Dafeng Hui, Avedananda Ray, Lovish Kasrija, Jaekedah Christian

Biology Faculty Research

Microbial-driven processes, including nitrification and denitrification closely related to soil nitrous oxide (N2O) production, are orchestrated by a network of enzymes and genes such as amoA genes from ammonia-oxidizing bacteria (AOB) and archaea (AOA), narG (nitrate reductase), nirS and nirK (nitrite reductase), and nosZ (N2O reductase). However, how climatic factors and agricultural practices could influence these genes and processes and, consequently, soil N2O emissions remain unclear. In this comprehensive review, we quantitatively assessed the effects of these factors on nitrogen processes and soil N2O emissions using mega-analysis (i.e., meta-meta-analysis). The results showed that global warming increased soil nitrification and denitrification …

Editorial: Volume Ii: Fibrotic Tissue Remodeling As A Driver Of Disease Pathogenesis, Arkadeep Mitra, Sarika Saraswati, Trayambak Basak

Biology Faculty Research

No abstract provided.

Editorial: Climate Change And/Or Pollution On The Carbon Cycle In Terrestrial Ecosystems, Junjie Lin, Dafeng Hui, Amit Kumar, Zhiguo Yu, Yuhan Huang

Biology Faculty Research

No abstract provided.

Public Health Importance Of Preventive Measures For Salmonella Tennessee And Salmonella Typhimurium Strain Lt2 Biofilms, Simen Asefaw, Sadiye Aras, Md Niamul Kabir, Sabrina Wadood, Shahid Chowdhury, Aliyar Cyrus Fouladkhah

Biology Faculty Research

Various serovars of Salmonella had been the subject of research for over 150 years; nonetheless, the bacterium has remained an important pathogen of public health concern to date. The tremendous ability of Salmonella to form biofilms on biotic and abiotic surfaces is an important underlying reason for the prevalence of this opportunistic pathogen in healthcare, manufacturing, and the food chain. The current study illustrates that using very common industrial antimicrobial treatments at the highest concentrations suggested by the manufacturers is only efficacious against planktonic and one-day mature biofilms of the pathogen while exhibiting a lack of efficacy for complete removal …

Evaluation Of Eastern Gamagrass As Dual-Purpose Complementary Bioenergy And Forage Feedstock To Switchgrass, Christina Kieffer, Dafeng Hui, Roser Matamala, Jianwei Li, Donald Tyler, E. Kudjo Dzantor

Biology Faculty Research

Switchgrass (SG) is considered a model bioenergy crop and a warm-season perennial grass (WSPG) that traditionally served as forage feedstock in the United States. To avoid the sole dependence on SG for bioenergy production, evaluation of other crops to diversify the pool of feedstock is needed. We conducted a 3-year field experiment evaluating eastern gamagrass (GG), another WSPG, as complementary feedstock to SG in one- and two-cut systems, with or without intercropping with crimson clover or hairy vetch, and under different nitrogen (N) application rates. Our results showed that GG generally produced lower biomass (by 29.5%), theoretical ethanol potential (TEP, …

Response Patterns Of Simulated Corn Yield And Soil Nitrous Oxide Emission To Precipitation Change, Navneet Kaur, Dafeng Hui, Daniel M. Riccuito, Melanie A. Mayes, Hanqin Tian

Biology Faculty Research

Background

Precipitation plays an important role in crop production and soil greenhouse gas emissions. However, how crop yield and soil nitrous oxide (N2O) emission respond to precipitation change, particularly with different background precipitations (dry, normal, and wet years), has not been well investigated. In this study, we examined the impacts of precipitation changes on corn yield and soil N2O emission using a long-term (1981–2020, 40 years) climate dataset as well as seven manipulated precipitation treatments with different background precipitations using the DeNitrification-DeComposition (DNDC) model.

Results

Results showed large variations of corn yield and precipitation but small variation of soil N2O …

Nutrient Resorption And Stoichiometric Characteristics Of Wuyi Rock Tea Cultivars, Dehuang Zhu, Suhong Peng, Wenzhen Liu, Shengjie Yu, Dafeng Hui

Biology Faculty Research

Nutrient resorption is an important strategy for plants to retain critical nutrients from senesced leaves and plays important roles in nutrient cycling and ecosystem productivity. As a main economic crop and soil and water conservation species, Wuyi Rock tea has been widely planted in Fujian Province, China. However, foliar nutrient resorptions of Wuyi Rock tea cultivars have not been well quantified. In this study, three Wuyi Rock tea cultivars (Wuyi Jingui, Wuyi Rougui, and Wuyi Shuixian) were selected in the Wuyishan National Soil and Water Conservation, Science and Technology Demonstration Park. Resorption efficiencies of nitrogen (NRE), phosphorus (PRE), and potassium …

Four In One: Cryptic Diversity In Geoffroy’S Side-Necked Turtle Phrynops Geoffroanus (Schweigger 1812) (Testudines: Pleurodira: Chelidae) In Brazil, V. T. De Carvalho, R. C. Vogt, R. R. Rojas, M. D. S. Nunes, R. De Fraga, R. W. Ávila, A. G J Rhodin, R. A. Mittermeier, Tomas Hrbek, I. P. Farias

Biology Faculty Research

Turtles are one of the most threatened groups of vertebrates, with about 60% of species classified at some level of extinction risk. Compounding this extinction crisis are cryptic species and species complexes that are evaluated under a single species epithet but harbor multiple species, each of which needs to be evaluated independently. The Phrynops geoffroanus species group is a classic example. Described first in 1812, it is currently thought to harbor multiple species. To test this hypothesis, we collected mitochondrial and nuclear genomic data, morphometric data, and distribution and associated biome information. We applied statistically rigorous species delimitation analyses, taxonomic …

Molecular Approaches For The Validation Of The Baboon As A Nonhuman Primate Model For The Study Of Zika Virus Infection, Emma Mask, V. L. Hodara, Jessica E. Callery, L. M. Parodi, V. Obregon-Perko, S. Yagi, J. Glenn, P. Frost, E. Clemmons, J. L. Patterson, L. A. Cox, Luis D. Giavedoni

Biology Faculty Research

Nonhuman primates (NHP) are particularly important for modeling infections with viruses that do not naturally replicate in rodent cells. Zika virus (ZIKV) has been responsible for sporadic epidemics, but in 2015 a disseminated outbreak of ZIKV resulted in the World Health Organization declaring it a global health emergency. Since the advent of this last epidemic, several NHP species, including the baboon, have been utilized for modeling and understanding the complications of ZIKV infection in humans; several health issues related to the outcome of infection have not been resolved yet and require further investigation. This study was designed to validate, in …

Cingulin Binds To The Zu5 Domain Of Scaffolding Protein Zo-1 To Promote Its Extended Conformation, Stabilization, And Tight Junction Accumulation, E. Vasileva, D. Spadaro, F. Rouaud, Jonathan M. King, A. Flinois, J. Shah, S. Sluysmans, I. Méan, L. Jond, J. R. Turner, S. Citi

Biology Faculty Research

Zonula occludens-1 (ZO-1), the major scaffolding protein of tight junctions (TJs), recruits the cytoskeleton-associated proteins cingulin (CGN) and paracingulin (CGNL1) to TJs by binding to their N-terminal ZO-1 interaction motif. The conformation of ZO-1 can be either folded or extended, depending on cytoskeletal tension and intramolecular and intermolecular interactions, and only ZO-1 in the extended conformation recruits the transcription factor DbpA to TJs. However, the sequences of ZO-1 that interact with CGN and CGNL1 and the role of TJ proteins in ZO-1 TJ assembly are not known. Here, we used glutathione-S-transferase pulldowns and immunofluorescence microscopy to show that CGN and …

Ahead Of His Time: Joseph Grinnell, Natural History, And Inclusion And Equity In Stem, David O. Ribble

Biology Faculty Research

Joseph Grinnell designed the Natural History of the Vertebrates (NHV) course at the Museum of Vertebrate Zoology, University of California at Berkeley, over 100 years ago and the course has changed little over these years. In this essay, I connect modern pedagogical and cognitive understandings of what we know leads to success among students to the course. This analysis reveals that the course continues to be successful because it has all the elements of a student-centered, active-learning class that leads to better cognitive gains, better retention, and importantly, proportionately better gains for students from underserved populations. This study will be …

Ancient Dna Of The Pygmy Marmoset Type Specimen Cebuella Pygmaea (Spix, 1823) Resolves A Taxonomic Conundrum, J. P. Boubli, M. C. Janiak, L. M. Porter, Stella De La Torre, L. Cortés-Ortiz, M. N. F. Da Silva, A. B. Rylands, Stephen Nash, F. Bertuol, H. Byrne, F. E. Silva, F. Rohe, D. De Vries, R. M. D. Beck, I. Ruiz-Gartzia, L. F. K. Kuderna, T. Marques-Bonet, Tomas Hrbek, I. P. Farias, A. H. Van Heteren, C. Roos

Biology Faculty Research

The pygmy marmoset, the smallest of the anthropoid primates, has a broad distribution in Western Amazonia. Recent studies using molecular and morphological data have identified two distinct species separated by the Napo and Solimões-Amazonas rivers. However, reconciling this new biological evidence with current taxonomy, i.e., two subspecies, Cebuella pygmaea pygmaea (Spix, 1823) and Cebuella pygmaea niveiventris (Lönnberg, 1940), was problematic given the uncertainty as to whether Spix’s pygmy marmoset (Cebuella pygmaea pygmaea) was collected north or south of the Napo and Solimões-Amazonas rivers, making it unclear to which of the two newly revealed species the name pygmaea would …

Mapping The Hidden Diversity Of The Geophagus Sensu Stricto Species Group (Cichlidae: Geophagini) From The Amazon Basin, A. M. Ximenes, P. S. Bittencourt, V. N. Machado, Tomas Hrbek, I. P. Farias

Biology Faculty Research

South American freshwater ichthyofauna is taxonomically the most diverse on the planet, yet its diversity is still vastly underestimated. The Amazon basin alone holds more than half of this diversity. The evidence of this underestimation comes from the backlog of morphologically distinct, yet undescribed forms deposited in museum collections, and from DNA-based inventories which consistently identify large numbers of divergent lineages within even well-studied species groups. In the present study, we investigated lineage diversity within the Geophagus sensu stricto species group. To achieve these objectives, we analyzed 337 individuals sampled from 77 locations within and outside the Amazon basin representing …

Synapsej: An Automated, Synapse Identification Macro For Imagej, Juan Felipe Moreno Manrique, Parker R. Voit, Kathryn E. Windsor, Aamuktha Reddy Karla, Sierra R. Rodriguez, Gerard M.J. Beaudoin Iii

Biology Faculty Research

While electron microscopy represents the gold standard for detection of synapses, a number of limitations prevent its broad applicability. A key method for detecting synapses is immunostaining for markers of pre- and post-synaptic proteins, which can infer a synapse based upon the apposition of the two markers. While immunostaining and imaging techniques have improved to allow for identification of synapses in tissue, analysis and identification of these appositions are not facile, and there has been a lack of tools to accurately identify these appositions. Here, we delineate a macro that uses open-source and freely available ImageJ or FIJI for analysis …

Linking Ecomechanical Models And Functional Traits To Understand Phenotypic Diversity, T. E. Higham, L. A. Ferry, L. Schmitz, D. J. Irschick, S. Starko, P. S L Anderson, P. J. Bergmann, H. A. Jamniczky, L. R. Monteiro, D. Navon, J. Messier, E. Carrington, S. C. Farina, K. L. Feilich, L. P. Hernandez, Michele A. Johnson, S. M. Kawano, C. J. Law, S. J. Longo, C. H. Martin, P. T. Martone, A. Rico-Guevara, S. E. Santana, K. J. Niklas

Biology Faculty Research

Physical principles and laws determine the set of possible organismal phenotypes. Constraints arising from development, the environment, and evolutionary history then yield workable, integrated phenotypes. We propose a theoretical and practical framework that considers the role of changing environments. This 'ecomechanical approach' integrates functional organismal traits with the ecological variables. This approach informs our ability to predict species shifts in survival and distribution and provides critical insights into phenotypic diversity. We outline how to use the ecomechanical paradigm using drag-induced bending in trees as an example. Our approach can be incorporated into existing research and help build interdisciplinary bridges. Finally, …

Season Of Prescribed Fire Determines Grassland Restoration Outcomes After Fire Exclusion And Overgrazing, Erin N. Novak, Michelle Bertelsen, Dick Davis, Devin M. Grobert, Kelly G. Lyons, Jason P. Martina, W. Matt Mccaw, Matthew O'Toole, Joseph W. Veldman

Biology Faculty Research

Fire exclusion and mismanaged grazing are globally important drivers of environmental change in mesic C₄ grasslands and savannas. Although interest is growing in prescribed fire for grassland restoration, we have little long-term experimental evidence of the influence of burn season on the recovery of herbaceous plant communities, encroachment by trees and shrubs, and invasion by exotic grasses. We conducted a prescribed fire experiment (seven burns between 2001 and 2019) in historically fire-excluded and overgrazed grasslands of central Texas. Sites were assigned to one of four experimental treatments: summer burns (warm season, lightning season), fall burns (early cool season), winter …

Culturable Root Endophyte Communities Are Shaped By Both Warming And Plant Host Identity In The Rocky Mountains, Usa, Kelly G. Lyons, M. Mann, Molly Lenihan, Olivia Roybal, Kelly Carroll, Kyle Reynoso, S. N. Kivlin, D. L. Taylor, J. A. Rudgers

Biology Faculty Research

Understanding the biogeographic patterns of root-associated fungi and their sensitivity to temperature may improve predictions of future changes in terrestrial biodiversity and associated ecosystem processes, but data are currently limited. Anticipating change will require combining observational data, which predict how climatic factors limit current species distributions, with direct manipulations of climate, which can isolate responses to specific climate variables. Root endophytes are common symbionts of plants, particularly in arctic and alpine environments, yet their responses to climate warming are not resolved. Here, we directly cultured endophytic fungi from roots collected along altitudinal gradients in replicated mountain watersheds and from a …

An Integrative Analysis Uncovers A New, Pseudo-Cryptic Species Of Amazonian Marmoset (Primates: Callitrichidae: Mico) From The Arc Of Deforestation, R. Costa-Araujo, J. S. Silva Jr., J. P. Boubli, R. V. Rossi, G. R. Canale, F. R. Melo, F. Bertuol, F. E. Silva, D. A. Silva, S. D. Nash, I. Sampaio, I. P. Farias, Tomas Hrbek

Biology Faculty Research

Amazonia has the richest primate fauna in the world. Nonetheless, the diversity and distribution of Amazonian primates remain little known and the scarcity of baseline data challenges their conservation. These challenges are especially acute in the Amazonian arc of deforestation, the 2500 km long southern edge of the Amazonian biome that is rapidly being deforested and converted to agricultural and pastoral landscapes. Amazonian marmosets of the genus Mico are little known endemics of this region and therefore a priority for research and conservation efforts. However, even nascent conservation efforts are hampered by taxonomic uncertainties in this group, such as the …

The Influence Of Social-Grouping On Territorial Defense Behavior In The Black-Crested Titmouse (Baeolophus Atricristatus), Mirjam J. Borger, Lauren E. Johnson, Nathaly O. Salazar, Cameron L. Dreghorn, J. Komdeur, Troy G. Murphy

Biology Faculty Research

Abstract: Status signals have evolved for individuals to avoid energetic and physical costs of resource defense. These signals reflect an individual’s competitive ability and therefore influence competitors’ decisions on how to invest in a fight. We hypothesized that the response of receivers to status signals will depend on the social context. During territorial defense, group members may provide support to a territory owner by participating in defense. We investigated whether the presence of juveniles—who group together with territorial males—alters the territorial male’s attack decisions and level of aggression in the black-crested titmouse (Baeolophus atricristatus). Crest-length in this species …

Roles For A Lipid Phosphatase In The Activation Of Its Opposing Lipid Kinase, Bethany S. Strunk, N. Steinfeld, S. Lee, N. Jin, Cecilia Munõz-Rivera, Garrison Meeks, Asha Mary Thomas, C. Akemann, A. K. Mapp, J. A. Macgurn, L. S. Weisman

Biology Faculty Research

Fig4 is a phosphoinositide phosphatase that converts PI3,5P2 to PI3P. Paradoxically, mutation of Fig4 results in lower PI3,5P2, indicating that Fig4 is also required for PI3,5P2 production. Fig4 promotes elevation of PI3,5P2, in part, through stabilization of a protein complex that includes its opposing lipid kinase, Fab1, and the scaffold protein Vac14. Here we show that multiple regions of Fig4 contribute to its roles in the elevation of PI3,5P2: Its catalytic site, an N-terminal disease-related surface, and a C-terminal region. We show that mutation of the Fig4 catalytic site enhances the formation of the Fab1-Vac14-Fig4 complex, and reduces the ability …

Baseline And Stress-Induced Corticosterone Levels Across Birds And Reptiles Do Not Reflect Urbanication Levels, A. S. Injaian, C. D. Francis, J. Q. Ouyang, D. M. Dominoni, Jeremy W. Donald, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, T. D. Williams, Maren N. Vitousek

Biology Faculty Research

Rates of human-induced environmental change continue increasing with human population size, potentially altering animal physiology and negatively affecting wildlife. Researchers often use glucocorticoid concentrations (hormones that can be associated with stressors) to gauge the impact of anthropogenic factors (e.g. urbanization, noise and light pollution). Yet, no general relationships between human-induced environmental change and glucocorticoids have emerged. Given the number of recent studies reporting baseline and stress-induced corticosterone (the primary glucocorticoid in birds and reptiles) concentrations worldwide, it is now possible to conduct large-scale comparative analyses to test for general associations between disturbance and baseline and stress-induced corticosterone across species. Additionally, …

Maternal Diabetes And Obesity Influence The Fetal Epigenome In A Largely Hispanic Population, Heather E. Rizzo, E. N. Escaname, Nicholas B. Alana, E. Lavender, J. Gelfond, R. Fernandez, Matthew A. Hibbs, Jonathan M. King, N. R. Carr, C. L. Blanco

Biology Faculty Research

BACKGROUND:

Obesity and diabetes mellitus are directly implicated in many adverse health consequences in adults as well as in the offspring of obese and diabetic mothers. Hispanic Americans are particularly at risk for obesity, diabetes, and end-stage renal disease. Maternal obesity and/or diabetes through prenatal programming may alter the fetal epigenome increasing the risk of metabolic disease in their offspring. The aims of this study were to determine if maternal obesity or diabetes mellitus during pregnancy results in a change in infant methylation of CpG islands adjacent to targeted genes specific for obesity or diabetes disease pathways in a largely …

Telophase Correction Refines Division Orientation In Stratified Epithelia, K. J. Lough, K. M. Byrd, C. P. Descovich, D. C. Spitzer, A. J. Bergman, Gerard M.J. Beaudoin Iii, L. F. Reichardt, S. E. Williams

Biology Faculty Research

During organogenesis, precise control of spindle orientation balances proliferation and differentiation. In the developing murine epidermis, planar and perpendicular divisions yield symmetric and asymmetric fate outcomes, respectively. Classically, division axis specification involves centrosome migration and spindle rotation, events occurring early in mitosis. Here, we identify a novel orientation mechanism which corrects erroneous anaphase orientations during telophase. The directionality of reorientation correlates with the maintenance or loss of basal contact by the apical daughter. While the scaffolding protein LGN is known to determine initial spindle positioning, we show that LGN also functions during telophase to reorient oblique divisions toward perpendicular. The …

Ritualized Display Of A Leaf: A Putative Agonistic Signal In Both Sexes Of Tropical Bird, L. M. Kiere, Troy G. Murphy, A. Garcia-Muñoz, M. Osorio-Beristain

Biology Faculty Research

Birds use many different signaling modalities (e.g. vocalizations, displays) to transmit information about their motivation to defend valuable resources. A handful of taxa use "props", inedible objects scavenged from the environment, in signaling. Several species of motmots (Coraciiformes) hold a leaf in their bill in a display that observational evidence suggests is agonistic. We used a simulated intruder experiment to test this display's agonistic signaling function using data from both members of pairs of russet-crowned motmots (Momotus mexicanus). If the display is agonistic, we expected territory-holding pairs to respond more strongly toward taxidermic mounts displaying a leaf. Our results showed …

Painted Bunting (Passerina Ciris) Caught In The Web Of A Giant Lichen Orb-Weaver Spider (Araneus Bicentenarius), Philip Queller, Troy G. Murphy

Biology Faculty Research

Orb-weaver spiders weave large webs that are capable of entrapping various species of birds. We report a case of a male Painted Bunting (Passerina ciris) caught in the web of a giant lichen orb-weaver (Araneus bicentenarius). Most cases of bird entrapment in spider webs involve spiders with larger webs (often Nephila sp.) and very small birds, usually hummingbirds. Our case is noteworthy because we report a relatively large bird caught in a relatively small web. Furthermore, the geographic distribution of A. bicentenarius extends beyond the tropics and subtropics, which is where most reported cases of bird …

Rapid Evolution Of Testis Size Relative To Sperm Morphology Suggests That Post-Copulatory Selection Targets Sperm Number In Anolis Lizards, A. F. Kahrl, Michele A. Johnson, R. M. Cox

Biology Faculty Research

Post-copulatory sexual selection is thought to be responsible for much of the extraordinary diversity in sperm morphology across metazoans. However, the extent to which post-copulatory selection targets sperm morphology versus sperm production is generally unknown. To address this issue, we simultaneously characterized the evolution of sperm morphology (length of the sperm head, midpiece and flagellum) and testis size (a proxy for sperm production) across 26 species of Anolis lizards, a group in which sperm competition is likely. We found that the length of the sperm midpiece has evolved 2–3 times faster than that of the sperm head or flagellum, suggesting …

Pharmacological Properties Of Chromobacterium Violaceum Violacein At The Human Serotonin 2c Receptor, Letimicia S. Fears, Mary E. Curtis, Terrance L. Johnson, Hugh M. Fentress

Biology Faculty Research

The monoamine neurotransmitter serotonin (5-HT) plays a role in many physiological responses by interacting with various receptor subtypes. The 5-HT_2C receptor subtype is a 7-transmembrane, G protein-coupled receptor (GPCR) that is involved in neuronal excitability, spatial learning, mood, and appetite. The microorganism Chromobacterium violaceum produces a purple pigment, violacein, which can be extracted and purified. Violacein has antibiotic, antileishmanial, antifungal and antitumoral properties in various cancer cell lines. Violacein is derived from the amino acid tryptophan as is 5-HT and therefore, the two have similar chemical structures. However, no one has reported the activity of violacein at 5-HT receptors. …

Macroevolutionary Patterning In Glucocorticoids Suggests Different Selective Pressures Shape Baseline And Stress-Induced Levels, Maren N. Vitousek, Michele A. Johnson, C. J. Downs, E. T. Miller, L. B. Martin, C. D. Francis, Jeremy W. Donald, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Bonnie K. Kircher, R. Knapp, L. A. Schoenle, T. D. Williams

Biology Faculty Research

Glucocorticoid (GC) hormones are important phenotypic mediators across vertebrates, but their circulating concentrations can vary markedly. Here we investigate macroevolutionary patterning in GC levels across tetrapods by testing seven specific hypotheses about GC variation and evaluating whether the supported hypotheses reveal consistent patterns in GC evolution. If selection generally favors the “supportive” role of GCs in responding effectively to challenges, then baseline and/or stress-induced GCs may be higher in challenging contexts. Alternatively, if selection generally favors “protection” from GC-induced costs, GCs may be lower in environments where challenges are more common or severe. The predictors of baseline GCs were all …

Ventral Tegmental Area Astrocytes Orchestrate Avoidance And Approach Behavior, J. A. Gomez, J. M. Perkins, Gerard M.J. Beaudoin Iii, N. B. Cook, S. A. Quraishi, E. A. Szoeke, K. Thangamani, C. W. Tschumi, M. J. Wanat, A. M. Maroof, M. J. Beckstead, P. A. Rosenberg, C. A. Paladini

Biology Faculty Research

The ventral tegmental area (VTA) is a heterogeneous midbrain structure, containing neurons and astrocytes, that coordinates behaviors by integrating activity from numerous afferents. Within neuron-astrocyte networks, astrocytes control signals from distinct afferents in a circuit-specific manner, but whether this capacity scales up to drive motivated behavior has been undetermined. Using genetic and optical dissection strategies we report that VTA astrocytes tune glutamatergic signaling selectively on local inhibitory neurons to drive a functional circuit for learned avoidance. In this circuit, astrocytes facilitate excitation of VTA GABA neurons to increase inhibition of dopamine neurons, eliciting real-time and learned avoidance behavior that is …