Biology Commons^™

Nuclear And Cytoplasmic Spatial Protein Quality Control Is Coordinated By Nuclear–Vacuolar Junctions And Perinuclear Escrt, Emily M. Sontag, Fabián Morales-Polanco, Jian-Hua Chen, Gerry Mcdermott, Patrick T. Dolan, Dan Gestaut, Mark A. Le Gros, Carolyn Larabell, Judith Frydman

Biological Sciences Faculty Research and Publications

Effective protein quality control (PQC), essential for cellular health, relies on spatial sequestration of misfolded proteins into defined inclusions. Here we reveal the coordination of nuclear and cytoplasmic spatial PQC. Cytoplasmic misfolded proteins concentrate in a cytoplasmic juxtanuclear quality control compartment, while nuclear misfolded proteins sequester into an intranuclear quality control compartment (INQ). Particle tracking reveals that INQ and the juxtanuclear quality control compartment converge to face each other across the nuclear envelope at a site proximal to the nuclear–vacuolar junction marked by perinuclear ESCRT-II/III protein Chm7. Strikingly, convergence at nuclear–vacuolar junction contacts facilitates VPS4-dependent vacuolar clearance of misfolded cytoplasmic …

Phase Separation In Biology And Disease; Current Perspectives And Open Questions, Steven Boeynaems, Shasha Chong, Jörg Gsponer, Liam Holt, Dragomir Milovanovic, Diana M. Mitrea, Oliver Mueller-Cajar, Bede Portz, John F. Reilly, Christopher D. Reinkemeier, Benjamin R. Sabari, Serena Sanulli, James Shorter, Emily M. Sontag, Lucia Strader, Jeanne Stachowiak, Stephanie C. Weber, Michael R. White, Huaiying Zhang, Markus Zweckstetter, Shana Elbaum-Garfinkle, Richard Kriwacki

Biological Sciences Faculty Research and Publications

In the past almost 15 years, we witnessed the birth of a new scientific field focused on the existence, formation, biological functions, and disease associations of membraneless bodies in cells, now referred to as biomolecular condensates. Pioneering studies from several laboratories supported a model wherein biomolecular condensates associated with diverse biological processes form through the process of phase separation. These and other findings that followed have revolutionized our understanding of how biomolecules are organized in space and time within cells to perform myriad biological functions, including cell fate determination, signal transduction, endocytosis, regulation of gene expression and protein translation, and …

Hyperdontia In The Paraguayan Martha's Marked Gecko (Homonota Marthae: Phyllodactylidae: Squamata), Juan D. Daza, Emma C. Krakoski, Tony Gamble, Aaron M. Bauer

Biological Sciences Faculty Research and Publications

No abstract provided.

The Role Of Preproglucagon Peptides In Regulating Β-Cell Morphology And Responses To Streptozotocin-Induced Diabetes, Deanna M. Arble, Chelsea R. Hutch, Hannah Hafner, Daria Stelmak, Kyle Leix, Joyce Sorrell, Joshua W. Pressler, Brigid Gregg, Darleen A. Sandoval

Biological Sciences Faculty Research and Publications

Insulin secretion from β-cells is tightly regulated by local signaling from preproglucagon (Gcg) products from neighboring α-cells. Physiological paracrine signaling within the microenvironment of the β-cell is altered after metabolic stress, such as high-fat diet or the β-cell toxin, streptozotocin (STZ). Here, we examined the role and source of Gcg peptides in β-cell function and in response to STZ-induced hyperglycemia. We used whole body Gcg null (Gcg^Null) mice and mice with Gcg expression either specifically within the pancreas (Gcg^ΔPanc) or the intestine (Gcg^ΔIntest). With lower doses of STZ exposure, insulin levels were …

Mycorrhizal Feedbacks Influence Global Forest Structure And Diversity, Camille S. Delavaux, Joseph A. Lamanna, Jonathan A. Myers, Richard P. Phillips

Biological Sciences Faculty Research and Publications

One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal …

Strong Dispersal Limitation Of Microbial Communities At Shackleton Glacier, Antarctica, Nathan P. Lemoine, Byron J. Adams, Melisa A. Diaz, Nicholas B. Dragone, Andre L.C. Franco, Noah Fierer, W. Berry Lyons, Ian Hogg, Diana H. Wall

Biological Sciences Faculty Research and Publications

Microbial communities can be structured by both deterministic and stochastic processes, but the relative importance of these processes remains unknown. The ambiguity partly arises from an inability to disentangle soil microbial processes from confounding factors, such as aboveground plant communities or anthropogenic disturbance. In this study, we characterized the relative contributions of determinism and stochasticity to assembly processes of soil bacterial communities across a large environmental gradient of undisturbed Antarctic soils. We hypothesized that harsh soils would impose a strong environmental selection on microbial communities, whereas communities in benign soils would be structured largely by dispersal. Contrary to our expectations, …

Allosteric Site At The Biotin Carboxylase Dimer Interface Mediates Activation And Inhibition In Staphylococcus Aureus Pyruvate Carboxylase, Amanda J. Laseke, Trevor J. Boram, Nicholas O. Schneider, Jeremy R. Lohman, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Allosteric regulation of the essential anaplerotic enzyme, pyruvate carboxylase (PC), is vital for metabolic homeostasis. PC catalyzes the bicarbonate- and ATP-dependent carboxylation of pyruvate to form oxaloacetate. Dysregulation of PC activity can impact glucose and redox metabolism, which contributes to the pathogenicity of many diseases. To maintain homeostasis, PC is allosterically activated by acetyl-CoA and allosterically inhibited by l-aspartate. In this study, we further characterize the molecular basis of allosteric regulation in Staphylococcus aureus PC (SaPC) using slowly/nonhydrolyzable dethia analogues of acetyl-CoA and site-directed mutagenesis of residues at the biotin carboxylase homodimer interface. The dethia analogues fully activate …

The Molecular Circadian Clock Of Phox2b-Expressing Cells Drives Daily Variation Of The Hypoxic But Not Hypercapnic Ventilatory Response In Mice, Aaron A. Jones, Gabriella M. Marino, Allison R. Spears, Deanna M. Arble

Biological Sciences Faculty Research and Publications

While the suprachiasmatic nucleus (SCN) controls 24-h rhythms in breathing, including minute ventilation (V_E), the mechanisms by which the SCN drives these daily changes are not well understood. Moreover, the extent to which the circadian clock regulates hypercapnic and hypoxic ventilatory chemoreflexes is unknown. We hypothesized that the SCN regulates daily breathing and chemoreflex rhythms by synchronizing the molecular circadian clock of cells. We used whole-body plethysmography to assess ventilatory function in transgenic BMAL1 knockout (KO) mice to determine the role of the molecular clock in regulating daily rhythms in ventilation and chemoreflex. Unlike their wild-type littermates, BMAL1 …

In Light Of Breathing: Environmental Light Is An Important Modulator Of Breathing With Clinical Implications, Aaron A. Jones, Deanna M. Arble

Biological Sciences Faculty Research and Publications

In vertebrate animals, the automatic, rhythmic pattern of breathing is a highly regulated process that can be modulated by various behavioral and physiological factors such as metabolism, sleep–wake state, activity level, and endocrine signaling. Environmental light influences many of these modulating factors both indirectly by organizing daily and seasonal rhythms of behavior and directly through acute changes in neural signaling. While several observations from rodent and human studies suggest that environmental light affects breathing, few have systematically evaluated the underlying mechanisms and clinical relevance of environmental light on the regulation of respiratory behavior. Here, we provide new evidence and discuss …

Tyramine And Its Amtyr1 Receptor Modulate Attention In Honey Bees (Apis Mellifera), Joseph S. Latshaw, Reece E. Mazade, Mary Peterson, Julie A. Mustard, Irina Sinakevitch, Lothar Wissler, Xiaojiao Guo, Chelsea N. Cook, Hong Lei, Jürgen Gadau, Brian Smith

Biological Sciences Faculty Research and Publications

Animals must learn to ignore stimuli that are irrelevant to survival and attend to ones that enhance survival. When a stimulus regularly fails to be associated with an important consequence, subsequent excitatory learning about that stimulus can be delayed, which is a form of nonassociative conditioning called ‘latent inhibition’. Honey bees show latent inhibition toward an odor they have experienced without association with food reinforcement. Moreover, individual honey bees from the same colony differ in the degree to which they show latent inhibition, and these individual differences have a genetic basis. To investigate the mechanisms that underly individual differences in …

Reappraising The Evolutionary History Of The Largest Known Gecko, The Presumably Extinct Hoplodactylus Delcourti, Via High-Throughput Sequencing Of Archival Dna, Matthew P. Heinicke, Stuart V. Nielsen, Aaron M. Bauer, Ryan Kelly, Anthony J. Geneva, Juan D. Daza, Shannon E. Keating, Tony Gamble

Biological Sciences Faculty Research and Publications

Hoplodactylus delcourti is a presumably extinct species of diplodactylid gecko known only from a single specimen of unknown provenance. It is by far the largest known gekkotan, approximately 50% longer than the next largest-known species. It has been considered a member of the New Zealand endemic genus Hoplodactylus based on external morphological features including shared toe pad structure. We obtained DNA from a bone sample of the only known specimen to generate high-throughput sequence data suitable for phylogenetic analysis of its evolutionary history. Complementary sequence data were obtained from a broad sample of diplodactylid geckos. Our results indicate that the …

Excess Dietary Sugar Alters Colonocyte Metabolism And Impairs The Proliferative Response To Damage, Ansen H.P. Burr, Junyi Ji, Kadir Ozler, Heather L. Mentrup, Onur Eskiocak, Brian Yueh, Rachel Cumberland, Ashley V. Menk, Natalie Rittenhouse, Christopher Marshall, Pailin Chiaranunt, Xiaoyi Zhang, Lauren Mullinax, Abigail Overacre-Delgoffe, Vaughn S. Cooper, Amanda C. Poholek, Greg M. Delgoffe, Kevin P. Mollen, Semir Beyaz, Timothy W. Hand

Biological Sciences Faculty Research and Publications

Background & Aims

The colonic epithelium requires continuous renewal by crypt resident intestinal stem cells (ISCs) and transit-amplifying (TA) cells to maintain barrier integrity, especially after inflammatory damage. The diet of high-income countries contains increasing amounts of sugar, such as sucrose. ISCs and TA cells are sensitive to dietary metabolites, but whether excess sugar affects their function directly is unknown.

Methods

Here, we used a combination of 3-dimensional colonoids and a mouse model of colon damage/repair (dextran sodium sulfate colitis) to show the direct effect of sugar on the transcriptional, metabolic, and regenerative functions of crypt ISCs and TA cells. …

Lin-35 Is Necessary In Both The Soma And Germline For Preserving Fertility In Caenorhabditis Elegans Under Moderate Temperature Stress, Brian P. Mikeworth, Frances V. Compere, Lisa N. Petrella

Biological Sciences Faculty Research and Publications

Maintenance of germline function under stress conditions is crucial for species survival. The germ line in many species is especially sensitive to elevated temperature. We have investigated the role of the pocket protein LIN-35 in preserving fertility in Caenorhabditis elegans under moderate temperature stress. We show that lin-35 mutants display several temperature sensitive germline defects, and more severe reductions in brood size at elevated temperatures compared to wild type. This loss of fertility under temperature stress is primarily due to loss of zygotic, but not maternal, LIN-35. Additionally, we have found that expression of LIN-35 is necessary in both the …

Navigating Rice Seedling Cold Resilience: Qtl Mapping In Two Inbred Line Populations And The Search For Genes, Michael Schläppi, Avery R. Jessel, Aaron K. Jackson, Huy Phan, Melissa H. Jia, Jeremy D. Edwards, Georgia C. Eizenga

Biological Sciences Faculty Research and Publications

Due to global climate change resulting in extreme temperature fluctuations, it becomes increasingly necessary to explore the natural genetic variation in model crops such as rice to facilitate the breeding of climate-resilient cultivars. To uncover genomic regions in rice involved in managing cold stress tolerance responses and to identify associated cold tolerance genes, two inbred line populations developed from crosses between cold-tolerant and cold-sensitive parents were used for quantitative trait locus (QTL) mapping of two traits: degree of membrane damage after 1 week of cold exposure quantified as percent electrolyte leakage (EL) and percent low-temperature seedling survivability (LTSS) after 1 …

Peripheral Clock Disruption And Metabolic Disease: Moving Beyond The Anatomy To A Functional Approach, Gabriella M. Marino, Deanna M. Arble

Biological Sciences Faculty Research and Publications

Sleep and circadian disruption are associated with an increased risk of metabolic disease, including obesity and diabetes. Mounting evidence indicates that misaligned and/or non-functional clock proteins in peripheral tissues critically contribute to the presentation of metabolic disease. Many of the foundational studies which led to this conclusion have focused on specific tissues such as the adipose, pancreas, muscle, and liver. While these studies have greatly advanced the field, the use of anatomical markers to manipulate tissue-specific molecular clocks may not be representative of the circadian disruption that occurs within the clinical population. In this manuscript, we argue that investigators can …

Identification Of A Cis-Sex Chromosome Transition In Banded Geckos (Coleonyx, Eublepharidae, Gekkota), Shannon E. Keating, Eli Greenbaum, Jerry D. Johnson, Tony Gamble

Biological Sciences Faculty Research and Publications

Sex-determination systems are highly variable amongst vertebrate groups, and the prevalence of genomic data has greatly expanded our knowledge of how diverse some groups truly are. Gecko lizards are known to possess a variety of sex-determination systems, and each new study increases our knowledge of this diversity. Here, we used RADseq to identify male-specific markers in the banded gecko Coleonyx brevis, indicating this species has a XX/XY sex-determination system. Furthermore, we show that these sex-linked regions are not homologous to the XX/XY sex chromosomes of two related Coleonyx species, C. elegans and C. mitratus, suggesting that a cis- …

Experimental And Observational Evidence Of Negative Conspecific Density Dependence In Temperate Extomycorrhizal Trees, Fiona V. Jevon, Dayna De La Cruz, Joseph A. Lamanna, Ashley K. Lang, David A. Orwig, Sydne Record, Paige V. Kouba, Matthew P. Ayres, Jaclyn H. Matthes

Biological Sciences Faculty Research and Publications

Conspecific negative density dependence (CNDD) promotes tree species diversity by reducing recruitment near conspecific adults due to biotic feedbacks from herbivores, pathogens, or competitors. While this process is well-described in tropical forests, tests of temperate tree species range from strong positive to strong negative density dependence. To explain this, several studies have suggested that tree species traits may help predict the strength and direction of density dependence: for example, ectomycorrhizal-associated tree species typically exhibit either positive or weaker negative conspecific density dependence. More generally, the strength of density dependence may be predictably related to other species-specific ecological attributes such as …

Ontogeny Of The Paraphalanges And Derived Phalanges Of Hemidactylus Turcicus (Squamata: Gekkonidae), Aaron H. Griffing, Tony Gamble, Aaron M. Bauer, Anthony P. Russell

Biological Sciences Faculty Research and Publications

Gekkotan lizards of the genus Hemidactylus exhibit derived digital morphologies. These include heavily reduced antepenultimate phalanges of digits III and IV of the manus and digits III–V of the pes, as well as enigmatic cartilaginous structures called paraphalanges. Despite this well-known morphological derivation, no studies have investigated the development of these structures. We aimed to determine if heterochrony underlies the derived antepenultimate phalanges of Hemidactylus. Furthermore, we aimed to determine if convergently evolved paraphalanges exhibit similar or divergent developmental patterns. Herein we describe embryonic skeletal development in the hands and feet of four gekkonid species, exhibiting a range of …

Thank You For Biting: Dispersal Of Beneficial Microbiota Through 'Antagonistic' Interactions, C.G.B. Grupstra, Nathan P. Lemoine, Chelsea N. Cook, Adrienne M.S. Correa

Biological Sciences Faculty Research and Publications

Multicellular organisms harbor populations of microbial symbionts; some of these symbionts can be dispersed through the feeding activities of consumers. Studies of consumer-mediated microbiota dispersal generally focus on pathogenic microorganisms; the dispersal of beneficial microorganisms has received less attention, especially in the context of 'antagonistic' trophic interactions (e.g., herbivory, parasitism, predation). Yet, this 'trophic transmission' of beneficial symbionts has significant implications for microbiota assembly and resource species (e.g., prey) health. For example, trophic transmission of microorganisms could assist with environmental acclimatization and help resource species to suppress other consumers or competitors. Here, we highlight model systems and approaches that have …

Genome-Wide Identification Of The A20/An1 Zinc Finger Proteon Family Genes In Ipomoea Batatas And Its Two Relatives And Function Analysis Of Ibsap16 In Salinity Tolerance, Hao Xie, Qiangqiang Yang, Xiaoxiao Wang, Michael Schläppi, Hui Yan, Meng Kou, Wei Tang, Xin Wang, Yungang Zhang, Qiang Li, Shaojun Dai, Yaju Liu

Biological Sciences Faculty Research and Publications

Stress-associated protein (SAP) genes—encoding A20/AN1 zinc-finger domain-containing proteins—play pivotal roles in regulating stress responses, growth, and development in plants. They are considered suitable candidates to improve abiotic stress tolerance in plants. However, the SAP gene family in sweet potato (Ipomoea batatas) and its relatives is yet to be investigated. In this study, 20 SAPs in sweet potato, and 23 and 26 SAPs in its wild diploid relatives Ipomoea triloba and Ipomoea trifida were identified. The chromosome locations, gene structures, protein physiological properties, conserved domains, and phylogenetic relationships of these SAPs were analyzed systematically. Binding motif analysis of IbSAPs indicated that …

Caloric Restriction Prevents Obesity- And Intermittent Hypoxia-Induced Cardiac Remodeling In Leptin-Deficient Ob/Ob Mice, Aaron A. Jones, Sarah N. Framnes-Deboer, Arianne Shipp, Deanna M. Arble

Biological Sciences Faculty Research and Publications

Background:

Intermittent hypoxia (IH), a key characteristic of obstructive sleep apnea, is independently associated with cardiometabolic impairment. While endogenous leptin levels may provide cardioprotective effects against hypoxia, leptin resistance is common among obese individuals presenting with obstructive sleep apnea.

Methods:

Here, we assessed left ventricle (LV) function using M-mode echocardiography in lean wild-type, calorically-restricted ob/ob, and obese ob/ob mice before and after 6 days of IH to determine how obesity and intermittent hypoxia interact to affect cardiac function independent of leptin signaling.

Results:

Calorically-restricting ob/ob mice for 4 weeks prior to IH exposure prevented weight gain (−2.1 ± 1.4 …

Diversity Of Reptile Sex Chromosome Evolution Revealed By Cytogenetic And Linked-Read Sequencing, Ze-Xian Zhu, Kazumi Matsubara, Foyez Shams, Jason Dobry, Erik Wapstra, Tony Gamble, Stephen D. Sarre, Arthur Georges, Jennifer A. Marshall Graves, Qi Zhou, Tariq Ezaz

Biological Sciences Faculty Research and Publications

Reptile sex determination is attracting much attention because the great diversity of sex-determination and dosage compensation mechanisms permits us to approach fundamental questions about mechanisms of sex chromosome turnover. Recent studies have made significant progress in better understanding diversity and conservation of reptile sex chromosomes, with however no reptile master sex determination genes identified. Here we describe an integrated genomics and cytogenetics pipeline, combining probes generated from the microdissected sex chromosomes with transcriptome and genome sequencing to explore the sex chromosome diversity in non-model Australian reptiles. We tested our pipeline on a turtle, two species of geckos, and a monitor …

Conformational Selection Governs Carrier Domain Positioning In Staphylococcus Aureus Pyruvate Carboxylase, Joshua H. Hakala, Amanda J. Laseke, Anya Lei Koza, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Biotin-dependent enzymes employ a carrier domain to efficiently transport reaction intermediates between distant active sites. The translocation of this carrier domain is critical to the interpretation of kinetic and structural studies, but there have been few direct attempts to investigate the dynamic interplay between ligand binding and carrier domain positioning in biotin-dependent enzymes. Pyruvate carboxylase (PC) catalyzes the MgATP-dependent carboxylation of pyruvate where the biotinylated carrier domain must translocate ∼70 Å from the biotin carboxylase domain to the carboxyltransferase domain. Many prior studies have assumed that carrier domain movement is governed by ligand-induced conformational changes, but the mechanism underlying this …

Recycled Concrete Aggregates Are An Economic Form Of Urban Riparian Erosion Management With Limited Impacts On Freshwater Chemistry And Microbial Diversity, Rachelle E. Beattie, Bixia Su, Rebecca Thill, Krassimira R. Hristova

Biological Sciences Faculty Research and Publications

Urban streams are at high risk of riparian erosion which impacts adjacent infrastructure stability. Methods to prevent stream erosion have been proposed including using recycled concrete (RC) materials to help stabilize the streambed; however, little is known about the environmental and biological impacts of using RC in urban streams. RC, new concrete (NC), and river rock controls were evaluated for their impact on water chemistry, water quality, and microbial community composition over 6.5 months in controlled laboratory mesocosms. Concentrations of 19 metals, nutrients, and pH of mesocosms containing RC were not significantly different from the river rock mesocosm throughout the …

Implications Of The Actin Cytoskeleton On The Multi-Step Process Of [ Psi+] Prion Formation, Jane E. Dorweiler, Douglas R. Lyke, Nathan P. Lemoine, Sam Guereca, Hannah E. Buchholz, Emily R. Legan, Claire M. Radtke, Anita L. Manogaran

Biological Sciences Faculty Research and Publications

Yeast prions are self-perpetuating misfolded proteins that are infectious. In yeast, [PSI⁺] is the prion form of the Sup35 protein. While the study of [PSI⁺] has revealed important cellular mechanisms that contribute to prion propagation, the underlying cellular factors that influence prion formation are not well understood. Prion formation has been described as a multi-step process involving both the initial nucleation and growth of aggregates, followed by the subsequent transmission of prion particles to daughter cells. Prior evidence suggests that actin plays a role in this multi-step process, but actin’s precise role is unclear. Here, we …

Vegetative Phenologies Of Lianas And Trees In Two Neotropical Forests With Contrasting Rainfall Regimes, Jose A. Medina-Vega, S. Joseph Wright, Frans Bongers, Stefan A. Schnitzer, Frank J. Sterck

Biological Sciences Faculty Research and Publications

• Among tropical forests, lianas are predicted to have a growth advantage over trees during seasonal drought, with substantial implications for tree and forest dynamics. We tested the hypotheses that lianas maintain higher water status than trees during seasonal drought and that lianas maximize leaf cover to match high, dry-season light conditions, while trees are more limited by moisture availability during the dry season.
• We monitored the seasonal dynamics of predawn and midday leaf water potentials and leaf phenology for branches of 16 liana and 16 tree species in the canopies of two lowland tropical forests with contrasting rainfall regimes in …

Plant Growth-Promoting Activity Of Bacteria Isolated From Asian Rice (Oryza Sativa L.) Depends On Rice Genotype, Nasim Maghboli Balasjin, James Maki, Michael Schläppi, Christopher Marshall

Biological Sciences Faculty Research and Publications

Asian rice is one of the most important crops because it is a staple food for almost half of the world’s population. To have production of rice keep pace with a growing world population, it is anticipated that the use of fertilizers will also need to increase, which may cause environmental damage through runoff impacts. An alternative strategy to increase crop yield is the use of plant growth-promoting bacteria. Thousands of microbial species can exist in association with plant roots and shoots, and some are critical to the plant’s survival. We isolated 140 bacteria from two distantly related rice accessions …

Immunosuppression Broadens Evolutionary Pathways To Drug Resistance And Treatment Failure During Acinetobacter Baumannii Pneumonia In Mice, Wenwen Ho, Lindsay M. Busch, Juan Hernandez-Bird, Efrat Hamami, Christopher Marshall, Edward Geisinger, Vaughn S. Cooper, Tim Van Opijnen, Jason W. Rosch, Ralph R. Isberg

Biological Sciences Faculty Research and Publications

Acinetobacter baumannii is increasingly refractory to antibiotic treatment in healthcare settings. As is true of most human pathogens, the genetic path to antimicrobial resistance (AMR) and the role that the immune system plays in modulating AMR during disease are poorly understood. Here we reproduced several routes to fluoroquinolone resistance, performing evolution experiments using sequential lung infections in mice that are replete with or depleted of neutrophils, providing two key insights into the evolution of drug resistance. First, neutropenic hosts acted as reservoirs for the accumulation of drug resistance during drug treatment. Selection for variants with altered drug sensitivity profiles arose …

Lianas Decelerate Tropical Forest Thinning During Succession, Jose A. Medina-Vega, Geertje M. F. Van Der Heijden, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

The well-established pattern of forest thinning during succession predicts an increase in mean tree biomass with decreasing tree density. The forest thinning pattern is commonly assumed to be driven solely by tree-tree competition. The presence of non-tree competitors could alter thinning trajectories, thus altering the rate of forest succession and carbon uptake. We used a large-scale liana removal experiment over 7 years in a 60- to 70-year-old Panamanian forest to test the hypothesis that lianas reduce the rate of forest thinning during succession. We found that lianas slowed forest thinning by reducing tree growth, not by altering tree recruitment or …

Immunosuppression Broadens Evolutionary Pathways To Treatment Failure During Acinetobacter Baumannii Pneumonia, Wenwen Huo, Lindsay M. Busch, Juan Hernandez-Bird, Efrat Hamami, Christopher Marshall, Edward Geisinger, Vaughn S. Cooper, Tim Van Opijnen, Jason W. Rosch, Ralph R. Isberg

Biological Sciences Faculty Research and Publications

Acinetobacter baumannii is increasingly refractory to antibiotic treatment in healthcare settings. As is true of most human pathogens, the genetic path to antimicrobial resistance (AMR) and the role that the immune system plays in modulating AMR during disease are poorly understood. Here we reproduced several routes to fluoroquinolone resistance, performing evolution experiments using sequential lung infections in mice that are replete or depleted of neutrophils, providing two key insights into the evolution of drug resistance. First, neutropenic hosts acted as reservoirs for the accumulation of drug resistance during drug treatment. Selection for variants with altered drug sensitivity profiles arose readily …