Biology Commons^™

A Comprehensive Synthesis Of Liana Removal Experiments In Tropical Forests, Sergio Estrada-Villegas, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

Lianas are a quintessential feature of tropical forests and are often perceived as being poorly studied. However, liana removal studies may be one of the most common experimental manipulations in tropical forest ecology. In this review, we synthesize data from 64 tropical liana removal experiments conducted over the past 90 yr. We explore the direction and magnitude of the effects of lianas on tree establishment, growth, survival, reproduction, biomass accretion, and plant and animal diversity in ecological and forestry studies. We discuss the geographical biases of liana removal studies and compare the various methods used to manipulate lianas. Overall, we …

Metabolic Comparison Of One-Anastomosis Gastric Bypass, Single-Anastomosis Duodenal-Switch, Roux-En-Y Gastric Bypass, And Vertical Sleeve Gastrectomy In Rat, Deanna M. Arble, Simon S. Evers, Nadajda Bozadjieva, Henriette Frikke-Schmidt, Andriy Myronovych, Alfor Lewis, Mouhamadoul Habib Toure, Randy J. Seeley

Biological Sciences Faculty Research and Publications

Background

One-anastomosis gastric bypass (OAGB) and single-anastomosis duodenal switch (SADS) have become increasingly popular weight loss strategies. However, data directly comparing the effectiveness of these procedures with Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (SG) are limited.

Objectives

To examine the metabolic outcomes of OAGB, SADS, RYGB, and SG in a controlled rodent model.

Setting

Academic research laboratory, United States.

Methods

Surgeries were performed in diet-induced obese Long-Evans rats, and metabolic outcomes were monitored before and for 15 weeks after surgery.

Results

All bariatric procedures induced weight loss compared with sham that lasted throughout the course of the study. …

Hepatic Glucagon-Receptor Signaling Enhances Insulin-Stimulated Glucose Disposal In Rodents, Teayoun Kim, Cassie L. Holleman, Shelly Nason, Deanna M. Arble, Nickki Ottaway, Joseph Chabenne, Christine Loyd, Jeong-A Kim, Darleen A. Sandoval, Daniel J. Drucker, Richard Dimarchi, Diego Perez-Tilve, Kirk M. Habegger

Biological Sciences Faculty Research and Publications

Glucagon receptor (GCGR) agonists cause hyperglycemia but also weight loss. However, GLP1R/GCGR mixed agonists do not exhibit the diabetogenic effects often attributed to GCGR activity. Thus, we sought to investigate the effect of glucagon agonism on insulin action and glucose homeostasis. Acute GCGR agonism induced immediate hyperglycemia, followed by improved glucose tolerance and enhanced glucose-stimulated insulin secretion. Moreover, acute GCGR agonism improved insulin tolerance in a dose-dependent manner in both lean and obese mice. Improved insulin tolerance was independent of GLP1R, FGF21, and hepatic glycogenolysis. Moreover, we observed increased glucose infusion rate, disposal, uptake, and suppressed endogenous glucose production during …

The Mitochondrial Single-Stranded Dna Binding Protein From S. Cerevisiae, Rim1, Does Not Form Stable Homo-Tetramers And Binds Dna As A Dimer Of Dimers, Saurabh P. Singh, Vandna Kukshal, Paolo De Bona, Edwin Antony, Roberto Galletto

Biological Sciences Faculty Research and Publications

Rim1 is the mitochondrial single-stranded DNA binding protein in Saccharomyces cerevisiae and functions to coordinate replication and maintenance of mtDNA. Rim1 can form homo-tetramers in solution and this species has been assumed to be solely responsible for ssDNA binding. We solved structures of tetrameric Rim1 in two crystals forms which differ in the relative orientation of the dimers within the tetramer. In testing whether the different arrangement of the dimers was due to formation of unstable tetramers, we discovered that while Rim1 forms tetramers at high protein concentration, it dissociates into a smaller oligomeric species at low protein concentrations. A …

Early Selection Of Bzip73 Facilitated Adaptation Of Japonica Rice To Cold Climates, Citao Liu, Shujun Ou, Bigang Mao, Jiuyou Tang, Wei Wang, Hongru Wang, Shouyun Cao, Michael Schläppi, Bingran Zhao, Guoying Xiao, Xiping Wang, Chengeai Chu

Biological Sciences Faculty Research and Publications

Cold stress is a major factor limiting production and geographic distribution of rice (Oryza sativa). Although the growth range of japonica subspecies has expanded northward compared to modern wild rice (O. rufipogon), the molecular basis of the adaptation remains unclear. Here we report bZIP73, a bZIP transcription factor-coding gene with only one functional polymorphism (+511 G>A) between the two subspecies japonica and indica, may have facilitated japonica adaptation to cold climates. We show the japonica version of bZIP73 (bZIP73^Jap) interacts with bZIP71 and modulates ABA levels and ROS homeostasis. Evolutionary and …

Energy Transduction In Nitrogenase, Lance C. Seefeldt, Brian M. Hoffman, John W. Peters, Simone Raugei, David N. Beratan, Edwin Antony, Dennis R. Dean

Biological Sciences Faculty Research and Publications

Nitrogenase is a complicated two-component enzyme system that uses ATP binding and hydrolysis energy to achieve one of the most difficult chemical reactions in nature, the reduction of N2 to NH3. One component of the Mo-based nitrogenase system, Fe protein, delivers electrons one at a time to the second component, the catalytic MoFe protein. This process occurs through a series of synchronized events collectively called the “Fe protein cycle”. Elucidating details of the events associated with this cycle has constituted an important challenge in understanding the nitrogenase mechanism. Electron delivery is a multistep process involving three metal clusters with intra- …

The Bidirectional Relationship Between Obstructive Sleep Apnea And Metabolic Disease, Sarah N. Framnes, Deanna M. Arble

Biological Sciences Faculty Research and Publications

Obstructive sleep apnea (OSA) is a common sleep disorder, effecting 17% of the total population and 40–70% of the obese population (1, 2). Multiple studies have identified OSA as a critical risk factor for the development of obesity, diabetes, and cardiovascular diseases (3–5). Moreover, emerging evidence indicates that metabolic disorders can exacerbate OSA, creating a bidirectional relationship between OSA and metabolic physiology. In this review, we explore the relationship between glycemic control, insulin, and leptin as both contributing factors and products of OSA. We conclude that while insulin and leptin action may contribute …

Poultry And Beef Meat As Potential Seedbeds For Antimicrobial Resistant Enterotoxigenic Bacillus Species: A Materializing Epidemiological And Potential Severe Health Hazard, Kamelia M. Osman, Ahmed Orabi, Anthony D. Kappell, Khalid S. Al-Maary, Ayman S. Mubarak, Turki M. Dawoud, Ihab M.I. Moussa, Hassan A. Hemeg, Ashgan M. Hessain, Hend M.Y. Yousef, Krassimira R. Hristova

Biological Sciences Faculty Research and Publications

Although Bacillus cereus is of particular concern in food safety and public health, the role of other Bacillus species was overlooked. Therefore, we investigated the presence of eight enterotoxigenic genes, a hemolytic gene and phenotypic antibiotic resistance profiles of Bacillusspecies in retail meat samples. From 255 samples, 124 Bacillus isolates were recovered, 27 belonged to B. cereusand 97 were non-B. cereus species. Interestingly, the non-B. cereus isolates carried the virulence genes and exhibited phenotypic virulence characteristics as the B. cereus. However, correlation matrix analysis revealed the B. cereus group positively …

Molecular Adaptations For Sensing And Securing Prey And Insight Into Amniote Genome Diversity From The Garter Snake Genome, Perry W. Perry, Daren C. Card, Joel W. Mcglothlin, Giulia I.M. Pasquesi, Richard H. Adams, Drew R. Schield, Nicole R. Hales, Andrew B. Corbin, Jeffery P. Demuth, Federico G. Hoffmann, Michael W. Vandewege, Ryan K. Schott, Nihar Bhattacharyya, Belinda S.W. Chang, Nicholas R. Casewell, Gareth Whiteley, Jacobo Reyes-Velasco, Stephen P. Mackessy, Tony Gamble, Kenneth B. Storey, Kyle K. Biggar, Courtney N. Passow, Chih-Horng Kuo, Suzanne E. Mcgaugh, Anne M. Bronikowski, A.P. Jason De Konig, Scott V. Edwards, Michael E. Pfrender, Patrick Minx, Edmund D. Brodie Iii, Edmund D. Brodie Jr., Wesley C. Warren, Todd A. Castoe

Biological Sciences Faculty Research and Publications

Colubridae represents the most phenotypically diverse and speciose family of snakes, yet no well-assembled and annotated genome exists for this lineage. Here, we report and analyze the genome of the garter snake, Thamnophis sirtalis, a colubrid snake that is an important model species for research in evolutionary biology, physiology, genomics, behavior, and the evolution of toxin resistance. Using the garter snake genome, we show how snakes have evolved numerous adaptations for sensing and securing prey, and identify features of snake genome structure that provide insight into the evolution of amniote genomes. Analyses of the garter snake and other squamate …

Stress Promotes Drug Seeking Through Glucocorticoid-Dependent Endocannabinoid Mobilization In The Prelimbic Cortex, Jayme R. Mcreynolds, Elizabeth M. Doncheck, Yan Li, Oliver Vranjkovic, Evan N. Graf, Daisuke Ogasawara, Benjamin F. Cravatt, David A. Baker, Qing-Song Liu, Cecilia J. Hillard, John R. Mantsch

Biological Sciences Faculty Research and Publications

Background

Clinical reports suggest that rather than directly driving cocaine use, stress may create a biological context within which other triggers for drug use become more potent. We hypothesize that stress-induced increases in corticosterone “set the stage” for relapse by promoting endocannabinoid-induced attenuation of inhibitory transmission in the prelimbic cortex (PL).

Methods

We have established a rat model for these stage-setting effects of stress. In this model, neither a stressor (electric footshock) nor stress-level corticosterone treatment alone reinstates cocaine seeking following self-administration and extinction, but each treatment potentiates reinstatement in response to an otherwise subthreshold cocaine priming dose (2.5 mg/kg, …

A High-Throughput Screening Assay For Pyruvate Carboxylase, Brittney N. Wyatt, Leggy A. Arnold, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Pyruvate carboxylase (PC) catalyzes the conversion of pyruvate to oxaloacetate (OAA), an important metabolic reaction in a wide range of organisms. Small molecules directed against PC would enable detailed studies on the metabolic role of this enzyme and would have the potential to be developed into pharmacological agents. Currently, specific and potentsmall molecule regulators of PC are unavailable. To assist in efforts to find, develop, and characterize small molecule effectors of PC, a novel fixed-time assay has been developed based on the reaction of OAA with the diazonium salt, Fast Violet B (FVB), which produces a colored adduct with …

Xx/Xy Sex Chromosomes In The South American Dwarf Gecko (Gonatodes Humeralis), Tony Gamble, Erin Mckenna, Wyatt Meyer, Stuart V. Nielsen, Brendan J. Pinto, Daniel P. Scantlebury, Timothy E. Higham

Biological Sciences Faculty Research and Publications

Sex-specific genetic markers identified using restriction site-associated DNA sequencing, or RADseq, permits the recognition of a species’ sex chromosome system in cases where standard cytogenetic methods fail. Thus, species with male-specific RAD markers have an XX/XY sex chromosome system (male heterogamety) while species with female-specific RAD markers have a ZZ/ZW sex chromosome (female heterogamety). Here, we use RADseq data from 5 male and 5 female South American dwarf geckos (Gonatodes humeralis) to identify an XX/XY sex chromosome system. This is the first confidently known sex chromosome system in a Gonatodes species. We used a low-coverage de novo G. …

Integrating Species Traits Into Species Pools, Marko J. Spasojevic, Christopher P. Catano, Joseph A. Lamanna, Jonathan A. Myers

Biological Sciences Faculty Research and Publications

Despite decades of research on the species‐pool concept and the recent explosion of interest in trait‐based frameworks in ecology and biogeography, surprisingly little is known about how spatial and temporal changes in species‐pool functional diversity (SPFD) influence biodiversity and the processes underlying community assembly. Current trait‐based frameworks focus primarily on community assembly from a static regional species pool, without considering how spatial or temporal variation in SPFD alters the relative importance of deterministic and stochastic assembly processes. Likewise, species‐pool concepts primarily focus on how the number of species in the species pool influences local biodiversity. However, species pools with similar …

Response To Comment On “Plant Diversity Increases With The Strength Of Negative Density Dependence At The Global Scale”, Joseph A. Lamanna, Scott A. Mangan, Alfonso Alonso, Norman A. Bourg, Warren Y. Brockelman, Sarayudh Bunyavejchewin, Li-Wan Chang, Iyh-Min Chiang, George B. Chuyong, Keith Clay, Susan Cordell, Stuart J. Davies, Tucker J. Furniss, Christian P. Giardina, I. A.U. Nimal Gunatilleke, C. V. Savitri Gunatilleke, Fangliang He, Robert W. Howe, Stephen P. Hubbell, Chang-Fu Hsieh, Faith M. Inman-Narahari, David Janik, Daniel J. Johnson, David Kenfack, Lisa Korte, Kamil Král, Andrew J. Larson, James A. Lutz, Sean M. Mcmahon, William J. Mcshea, Hervé R. Memiaghe, Anuttara Nathalang, Vojtech Novotny, Perry S. Ong, David A. Orwig, Rebecca Ostertag, Geoffrey G. Parker, Richard P. Phillips, Lawren Sack, I-Fang Sun, J. Sebastián Tello, Duncan W. Thomas, Benjamin L. Turner, Dilys M. Vela Díaz, Tomáš Vrška, George D. Weiblen, Amy Wolf, Sandra Yap, Jonathan A. Myers

Biological Sciences Faculty Research and Publications

Hülsmann and Hartig suggest that ecological mechanisms other than specialized natural enemies or intraspecific competition contribute to our estimates of conspecific negative density dependence (CNDD). To address their concern, we show that our results are not the result of a methodological artifact and present a null-model analysis that demonstrates that our original findings—(i) stronger CNDD at tropical relative to temperate latitudes and (ii) a latitudinal shift in the relationship between CNDD and species abundance—persist even after controlling for other processes that might influence spatial relationships between adults and recruits.

Terrestrial Laser Scanning To Detect Liana Impact On Forest Structure, Sruthi M. Krishna Moorthy, Kim Calders, Manfredo Di Porcia E Brugnera, Hans Verbeeck, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

Tropical forests are currently experiencing large-scale structural changes, including an increase in liana abundance and biomass. Higher liana abundance results in reduced tree growth and increased tree mortality, possibly playing an important role in the global carbon cycle. Despite the large amount of data currently available on lianas, there are not many quantitative studies on the influence of lianas on the vertical structure of the forest. We study the potential of terrestrial laser scanning (TLS) in detecting and quantifying changes in forest structure after liana cutting using a small scale removal experiment in two plots (removal plot and non-manipulated control …

Swimming Rhythm Generation In The Caudal Hindbrain Of The Lamprey, James T. Buchanan

Biological Sciences Faculty Research and Publications

The spinal cord has been well established as the site of generation of the locomotor rhythm in vertebrates, but studies have suggested that the caudal hindbrain in larval fish and amphibians can also generate locomotor rhythms. Here, we investigated whether the caudal hindbrain of the adult lamprey (Petromyzon marinus and Ichthyomyzon unicuspis) has the ability to generate the swimming rhythm. The hindbrain-spinal cord transition zone of the lamprey contains a bilateral column of somatic motoneurons that project via the spino-occipital (S-O) nerves to several muscles of the head. In the brainstem-spinal cord-muscle preparation, these muscles were found to …

Dynamic Sex Chromosomes In Old World Chameleons (Squamata: Chamaeleonidae), Stuart V. Nielsen, J. L. Banks, R. E. Diaz Jr., P. A. Trainor, Tony Gamble

Biological Sciences Faculty Research and Publications

Much of our current state of knowledge concerning sex chromosome evolution is based on a handful of ‘exceptional’ taxa with heteromorphic sex chromosomes. However, classifying the sex chromosome systems of additional species lacking easily identifiable, heteromorphic sex chromosomes is indispensable if we wish to fully understand the genesis, degeneration and turnover of vertebrate sex chromosomes. Squamate reptiles (lizards and snakes) are a potential model clade for studying sex chromosome evolution as they exhibit a suite of sex‐determining modes yet most species lack heteromorphic sex chromosomes. Only three (of 203) chameleon species have identified sex chromosome systems (all with female heterogamety, …

Dynamics Of E. Coli Single Stranded Dna Binding (Ssb) Protein-Dna Complexes, Edwin Antony, Timothy M. Lohman

Biological Sciences Faculty Research and Publications

Single stranded DNA binding proteins (SSB) are essential to the cell as they stabilize transiently open single stranded DNA (ssDNA) intermediates, recruit appropriate DNA metabolism proteins, and coordinate fundamental processes such as replication, repair and recombination. Escherichia coli single stranded DNA binding protein (EcSSB) has long served as the prototype for the study of SSB function. The structure, functions, and DNA binding properties of EcSSB are well established: The protein is a stable homotetramer with each subunit possessing an N-terminal DNA binding core, a C-terminal protein-protein interaction tail, and an intervening intrinsically disordered linker (IDL). EcSSB …

Functional Traits Of Tropical Trees And Lianas Explain Spatial Structure Across Multiple Scales, Adam Thomas Clark, Nattei Detto, Helene C. Muller-Laudau, Stefan A. Schnitzer, S. Joseph Wright, Richard Condit, Stephen P. Hubbell

Biological Sciences Faculty Research and Publications

1. Dispersal and density dependence are major determinants of spatial structure, population dynamics and coexistence for tropical forest plants. However, because these two processes can jointly influence spatial structure at similar scales, analysing spatial patterns to separate and quantify them is often difficult.
2. Species functional traits can be useful indicators of dispersal and density dependence. However, few methods exist for linking functional traits to quantitative estimates of these processes that can be compared across multiple species.
3. We analysed static spatial patterns of woody plant populations in the 50 ha Forest Dynamics Plot on Barro Colorado Island, Panama with methods that distinguished …

Lianas Reduce Community-Level Canopy Tree Reproduction In A Panamanian Forest, Maria M. Garcia Leon, Laura Martinez Izquierdo, Filipe Niery Arantes Mello, Jennifer S. Powers, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

1. Lianas are a key component of tropical forests, where they compete intensely with trees, reducing tree recruitment, growth and survival. One of the most important potential outcomes of liana competition is the reduction of tree reproduction; however, no previous study has experimentally determined the effects of lianas on tree reproduction beyond a single tree species.
2. We used a large‐scale liana removal experiment to quantify the effect of lianas on community‐level canopy and understorey tree and palm reproduction. In 2011, we removed lianas from eight 6,400‐m² plots (eight plots served as controls) and surveyed understorey tree reproduction in 2012, canopy …

Tree Species Vary Widely In Their Tolerance For Liana Infestation: A Case Study Of Differential Host Response To Generalist Parasites, Marco D. Visser, Stefan A. Schnitzer, Helene C. Muller-Laudau, Eelke Jongejans, Hans De Kroon, Liza S. Comita, Stephen P. Hubbell, S. Joseph Wright

Biological Sciences Faculty Research and Publications

1. Lianas are structural parasites of trees and reduce individual host tree growth, survival and fecundity. Thus, liana infestation is expected to affect tree population growth rates, with potentially different effects in different species depending on the frequency of liana infestation and the impact of liana infestation on population growth rates. Previous studies have documented the myriad negative effects of lianas on trees and variation in liana infestation among tree species; however, no study has quantified the impact of liana infestation on individual tree species population growth rates. Lianas are increasing in abundance in multiple Neotropical sites, which may have profound …

Does Soil Moisture Availability Explain Liana Seedling Distribution Across A Tropical Rainfall Gradient?, Eric Manzane-Pinzon, Guillermo Goldstein, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

Liana density tends to increase with decreasing rainfall and increasing seasonality. However, the pattern of liana distribution may be due to differences in soil water retention capacity, not rainfall and seasonality per se. We tested the effect of rainfall and soil substrate with respect to the distribution of liana seedlings in six sites across a rainfall gradient from the wet Atlantic to the dry Pacific in central Panama. Soils were either limestone, with low water-holding capacity, or laterite, with higher water-holding capacity. We sampled liana seedlings at each site using three 1 × 100 m transect. We found that …

Pleiotropic And Novel Phenotypes In The Drosophila Gut Caused By Mutation Of Drop-Dead, Sean Conway, Christine Lynn Sansone, Anika Benske, Kaitlin Kentala, Johan Billen, Jozef Vanden Broeck, Edward M. Blumenthal

Biological Sciences Faculty Research and Publications

Normal gut function is vital for animal survival, and deviations from such function can contribute to malnutrition, inflammation, increased susceptibility to pathogens, diabetes, neurodegenerative diseases, and cancer. In the fruit fly Drosophila melanogaster, mutation of the gene drop-dead (drd) results in defective gut function, as measured by enlargement of the crop and reduced food movement through the gut, and drd mutation also causes the unrelated phenotypes of neurodegeneration, early adult lethality and female sterility. In the current work, adult drd mutant flies are also shown to lack the peritrophic matrix (PM), an extracellular barrier that lines the lumen of the …

Allosteric Regulation Alters Carrier Domain Translocation In Pyruvate Carboxylase, Yumeng Liu, Melissa M. Budelier, Katelyn Stine, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Pyruvate carboxylase (PC) catalyzes the ATP-dependent carboxylation of pyruvate to oxaloacetate. The reaction occurs in two separate catalytic domains, coupled by the long-range translocation of a biotinylated carrier domain (BCCP). Here, we use a series of hybrid PC enzymes to examine multiple BCCP translocation pathways in PC. These studies reveal that the BCCP domain of PC adopts a wide range of translocation pathways during catalysis. Furthermore, the allosteric activator, acetyl CoA, promotes one specific intermolecular carrier domain translocation pathway. These results provide a basis for the ordered thermodynamic state and the enhanced carboxyl group transfer efficiency in the presence of …

Cryptic Diversity In The Neotropical Gecko Genus Phyllopezus Peters, 1878 (Reptilia: Squamata: Phyllodactylidae): A New Species From Paraguay, Pier Cacciali, Sebastian Lotzkat, Tony Gamble, Gunther Köhler

Biological Sciences Faculty Research and Publications

The gecko genus Phyllopezus is distributed mainly along South America’s “Dry Diagonal” (Caatinga, Cerrado, and Chaco). The genus has been the subject of recent taxonomic analyses and includes four described species and seven candidate species referred to here as Phyllopezus pollicaris sensu lato. In Paraguay, Phyllopezus is known from the Chaco and Cerrado where it is abundant, and also from a small isolated population from a rocky hill formation named “Cordillera de Los Altos” (Los Altos mountain range). Here we analyzed genetic samples from across its range, including new samples from Paraguay, using DNA barcoding analysis of the mitochondrial 16S …

Infanticide In Chimpanzees: Taphonomic Case Studies From Gombe, Claire A. Kirchhoff, Michael L. Wison, Deus C. Mjungu, Jane Raphael, Shadrack Kamenya, D. Anthony Collins

Biological Sciences Faculty Research and Publications

Objectives

We present a study of skeletal damage to four chimpanzee (Pan troglodytes) infanticide victims from Gombe National Park, Tanzania. Skeletal analysis may provide insight into the adaptive significance of infanticide by examining whether nutritional benefits sufficiently explain infanticidal behavior. The nutritional hypothesis would be supported if bone survivorship rates and skeletal damage patterns are comparable to those of monkey prey. If not, other explanations, such as the resource competition hypothesis, should be considered.

Methods

Taphonomic assessment of two chimpanzee infants included description of breakage and surface modification, data on MNE, %MNE, and bone survivorship. Two additional infants …

Mrpl35, A Mitospecific Component Of Mitoribosomes, Plays A Key Role In Cytochrome C Oxidase Assembly, Jodie M. Box, Jasvinder Kaur, Rosemary A. Stuart

Biological Sciences Faculty Research and Publications

Mitoribosomes perform the synthesis of the core components of the oxidative phosphorylation (OXPHOS) system encoded by the mitochondrial genome. We provide evidence that MrpL35 (mL38), a mitospecific component of the yeast mitoribosomal central protuberance, assembles into a subcomplex with MrpL7 (uL5), Mrp7 (bL27), and MrpL36 (bL31) and mitospecific proteins MrpL17 (mL46) and MrpL28 (mL40). We isolated respiratory defective mrpL35 mutant yeast strains, which do not display an overall inhibition in mitochondrial protein synthesis but rather have a problem in cytochrome coxidase complex (COX) assembly. Our findings indicate that MrpL35, with its partner Mrp7, play a key role in coordinating …

General And Specific Promotion Of Flagellar Assembly By A Flagellar Nucleoside Diphosphate Kinase, Xiaoyan Zhu, Emiliya Poghosyan, Radhika Gopal, Yi Liu, Kristine S. Ciruelas, Yousif Maizy, Dennis R. Diener, Stephen M. King, Takashi Ishikawa, Pinfen Yang

Biological Sciences Faculty Research and Publications

Nucleoside diphosphate kinases (NDKs) play a central role in diverse cellular processes using the canonical NDK activity or alternative mechanisms that remain poorly defined. Our study of dimeric NDK5 in a flagellar motility control complex, the radial spoke (RS), has revealed new modalities. The flagella in Chlamydomonas ndk5 mutant were paralyzed, albeit only deficient in three RS subunits. RS morphology appeared severely changed in averaged cryo-electron tomograms, suggesting that NDK5 is crucial for the intact spokehead formation as well as RS structural stability. Intriguingly, ndk5’s flagella were also short, resembling those of an allelic spoke-less mutant. All ndk5’s phenotypes were …

Klf9 And Jnk3 Interact To Suppress Axon Regeneration In The Adult Cns, Akintomide Apara, Joana Galvao, Yan Wang, Murray G. Blackmore, Allison Trillo, Keiichiro Iwao, Dale P. Brown Jr., Kimberly A. Fernandes, Abigail Huang, Tu Nguyen, Masoumeh Ashouri, Ziong Zhang, Peter S. Shaw, Noelia J. Kunzevitzky, Darcie L. Moore, Richard T. Libby, Jeffrey L. Goldberg

Biological Sciences Faculty Research and Publications

Neurons in the adult mammalian CNS decrease in intrinsic axon growth capacity during development in concert with changes in Krüppel-like transcription factors (KLFs). KLFs regulate axon growth in CNS neurons including retinal ganglion cells (RGCs). Here, we found that knock-down of KLF9, an axon growth suppressor that is normally upregulated 250-fold in RGC development, promotes long-distance optic nerve regeneration in adult rats of both sexes. We identified a novel binding partner, MAPK10/JNK3 kinase, and found that JNK3 (c-Jun N-terminal kinase 3) is critical for KLF9's axon-growth-suppressive activity. Interfering with a JNK3-binding domain or mutating two newly discovered serine phosphorylation acceptor …

Reversible Plasticity Of Detrusor Smooth Muscle: Evidence For A Key Role Of “Slipping” Actomyosin Cross-Bridges In The Control Of Urinary Bladder Compliance, Thomas J. Eddinger

Biological Sciences Faculty Research and Publications

No abstract provided.