Resource‐Based Habitat Associations In A Neotropical Liana Community, James W. Dalling, Stefan A. Schnitzer, Claire Baldeck, Kyle E. Harms, Robert John, Scott A. Mangan, Elena Lobo, Joseph B. Yavitt, Stephen P. Hubbell

Biological Sciences Faculty Research and Publications

Summary

1. Lianas are a conspicuous element of many tropical forests, accounting for up to 40% of woody stem density and 20% of species richness in seasonal forests. However, lianas have seldom been surveyed at sufficiently large spatial scales to allow an assessment of the importance of habitat variables in structuring liana communities.

2. We compare the association patterns of 82 liana species and an equivalent sample of tree species on the 50 ha Forest Dynamics Project plot on Barro Colorado Island, Panama, with topographic habitat variables (high and low plateau, slope, swamp and streamside), and thirteen mapped soil chemical …

Expression Of Recombinant Earli1, A Hybrid Proline-Rich Protein Of Arabidopsis, In Escherichia Coli And Its Inhibition Effect To The Growth Of Fungal Pathogens And Saccharomyces Cerevisiae, Lan Li, Chen Zhang, Dan Xu, Michael Schläppi, Zi-Qin Xu

Biological Sciences Faculty Research and Publications

EARLI1 is an Arabidopsis gene with pleiotropic effects previously shown to have auxiliary functions in protecting plants against freezing-induced cellular damage and promoting germinability under low-temperature and salinity stresses. Here we determined whether recombinant EARLI1 protein has anti-fungal activity. Recombinant EARLI1 protein lacking its signal peptide was produced in Escherichia coli BL21(DE3) using isopropyl β-d-1-thiogalactopyranoside (IPTG) induction and the prokaryotic expression vector pET28a. Expression of EARLI1 was analyzed by Western blotting and the protein was purified using affinity chromatography. Recombinant EARLI1 protein was applied to fungal cultures of Saccharomyces cerevisiae, Botrytis cinerea and Fusarium oxysporum, and membrane permeability …

The Ranging Costs Of A Fallback Food: Liana Consumption Supplements Diet But Increases Foraging Effort In Howler Monkeys, Jacob C. Dunn, Norberto Asensio, Victor Arroyo-Rodriguez, Stefan A. Schnitzer, Jurgi Cristóbal‐Azkarate

Biological Sciences Faculty Research and Publications

Lianas are important components in the dynamics of tropical forests and represent fallback foods for some primates, yet little is known about their impact on primate ecology, behavior or fitness. Using 2 yr of field data, we investigated liana consumption and foraging effort in four groups of howler monkeys (two in bigger, more conserved forest fragments and two in smaller, less conserved fragments) to assess whether howler monkeys use lianas when and where food availability is scarce, and how liana consumption is related to foraging effort. Howler monkeys in smaller fragments spent more time consuming lianas and liana consumption was …

Methylene Blue Modulates Huntingtin Aggregation Intermediates And Is Protective In Huntington's Disease Models, Emily M. Sontag, Gregor P. Lotz, Namita Agrawal, Andrew Tran, Rebecca Aron, Guocheng Yang, Mihaela Necula, Alice Lau, Steven Finkbeiner, Charles G. Glabe, J. Lawrence Marsh, Paul J. Muchowski, Leslie M. Thompson

Biological Sciences Faculty Research and Publications

Huntington's disease (HD) is a devastating neurodegenerative disorder with no disease-modifying treatments available. The disease is caused by expansion of a CAG trinucleotide repeat and manifests with progressive motor abnormalities, psychiatric symptoms, and cognitive decline. Expression of an expanded polyglutamine repeat within the Huntingtin (Htt) protein impacts numerous cellular processes, including protein folding and clearance. A hallmark of the disease is the progressive formation of inclusions that represent the culmination of a complex aggregation process. Methylene blue (MB), has been shown to modulate aggregation of amyloidogenic disease proteins. We investigated whether MB could impact mutant Htt-mediated aggregation and neurotoxicity. MB …

Plasmodium Falciparum Ssb Tetramer Binds Single-Stranded Dna Only In A Fully Wrapped Mode, Edwin Antony, Alexander G. Kozlov, Binh Nguyen, Timothy M. Lohman

Biological Sciences Faculty Research and Publications

The tetrameric Escherichia coli single-stranded DNA (ssDNA) binding protein (Ec-SSB) functions in DNA metabolism by binding to ssDNA and interacting directly with numerous DNA repair and replication proteins. Ec-SSB tetramers can bind ssDNA in multiple DNA binding modes that differ in the extent of ssDNA wrapping. Here, we show that the structurally similar SSB protein from the malarial parasite Plasmodium falciparum (Pf-SSB) also binds tightly to ssDNA but does not display the same number of ssDNA binding modes as Ec-SSB, binding ssDNA exclusively in fully wrapped complexes with site sizes of 52–65 nt/tetramer. Pf …

Plasmodium Falciparum Ssb Tetramer Wraps Single-Stranded Dna With Similar Topology But Opposite Polarity To E. Coli Ssb, Edwin Antony, Elizabeth A. Weiland, Sergey Korolev, Timothy M. Lohman

Biological Sciences Faculty Research and Publications

Single-stranded DNA binding (SSB) proteins play central roles in genome maintenance in all organisms. Plasmodium falciparum, the causative agent of malaria, encodes an SSB protein that localizes to the apicoplast and likely functions in the replication and maintenance of its genome. P. falciparum SSB (Pf-SSB) shares a high degree of sequence homology with bacterial SSB proteins but differs in the composition of its C-terminus, which interacts with more than a dozen other proteins in Escherichia coli SSB (Ec-SSB). Using sedimentation methods, we show that Pf-SSB forms a stable homo-tetramer alone and when bound to …

Repeated Origin And Loss Of Adhesive Toepads In Geckos, Tony Gamble, Eli Greenbaum, Todd R. Jackman, Anthony P. Russell, Aaron M. Bauer

Biological Sciences Faculty Research and Publications

Geckos are well known for their extraordinary clinging abilities and many species easily scale vertical or even inverted surfaces. This ability is enabled by a complex digital adhesive mechanism (adhesive toepads) that employs van der Waals based adhesion, augmented by frictional forces. Numerous morphological traits and behaviors have evolved to facilitate deployment of the adhesive mechanism, maximize adhesive force and enable release from the substrate. The complex digital morphologies that result allow geckos to interact with their environment in a novel fashion quite differently from most other lizards. Details of toepad morphology suggest multiple gains and losses of the adhesive …

The Mir-51 Family Of Micrornas Functions In Diverse Regulatory Pathways In Caenorhbditis Elegans, Allison L. Abbott, John L. Brenner, Benedict J. Kemp

Biological Sciences Faculty Research and Publications

The mir-51 family of microRNAs (miRNAs) in C. elegans are part of the deeply conserved miR-99/100 family. While loss of all six family members (mir-51-56) in C. elegans results in embryonic lethality, loss of individual mir-51 family members results in a suppression of retarded developmental timing defects associated with the loss of alg-1. The mechanism of this suppression of developmental timing defects is unknown. To address this, we characterized the function of the mir-51 family in the developmental timing pathway. We performed genetic analysis and determined that mir-51 family members regulate the developmental timing pathway in the L2 stage …

Novel Forests Maintain Ecosystem Processes After The Decline Of Native Tree Species, Joseph Mascaro, R. Flint Hughes, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

The positive relationship between species diversity (richness and evenness) and critical ecosystem functions, such as productivity, carbon storage, and nutrient cycling, is often used to predict the consequences of extinction. At regional scales, however, plant species richness is mostly increasing rather than decreasing because successful plant species introductions far outnumber extinctions. If these regional increases in richness lead to local increases in diversity, a reasonable prediction is that productivity, carbon storage, and nutrient cycling will increase following invasion, yet this prediction has rarely been tested empirically. We tested this prediction in novel forest communities dominated by introduced species (~90% basal …

Sex Determination, Tony Gamble

Biological Sciences Faculty Research and Publications

Multicellular animals are a diverse lot, with widely varied body plans and lifestyles. One feature they share, however, is a nearly universal reliance on sexual reproduction for species propagation. Humans have long been fascinated by human sex differences and formal theories on how human sex is determined date at least to Aristotle (in De Generatione Animalium, ca. 335 BCE). However, it is only in the past couple of decades that the genetic and molecular programs responsible for generating the two sexes have been understood in any detail. Sex, it turns out, can be established by many very different and …

Rcf1 And Rcf2, Members Of The Hypoxia-Induced Gene 1 Protein Family, Are Critical Components Of The Mitochondrial Cytochrome Bc1-Cytochrome C Oxidase Supercomplex, Vera Strogolova, Andrew Furness, Micaela Robb-Mcgrath, Joshua Garlich, Rosemary A. Stuart

Biological Sciences Faculty Research and Publications

We report that Rcf1 (formerly Aim31), a member of the conserved hypoxia-induced gene 1 (Hig1) protein family, represents a novel component of the yeast cytochrome bc₁-cytochrome c oxidase (COX) supercomplex. Rcf1 (respiratory supercomplex factor 1) partitions with the COX complex, and evidence that it may act as a bridge to the cytochrome bc₁ complex is presented. Rcf1 interacts with the Cox3 subunit and can do so prior to their assembly into the COX complex. A close proximity of Rcf1 and members of the ADP/ATP carrier (AAC) family was also established. Rcf1 displays overlapping function with another Hig1-related …

Microbial Biosafety Of Pilot-Scale Bioreactor Treating Mtbe And Tba-Contaminated Drinking Water Supply, Radomir Schmidt, David A. Klemme, Kate M. Scow, Krassimira R. Hristova

Biological Sciences Faculty Research and Publications

A pilot-scale sand-based fluidized bed bioreactor (FBBR) was utilized to treat both methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) from a contaminated aquifer. To evaluate the potential for re-use of the treated water, we tested for a panel of water quality indicator microorganisms and potential waterborne pathogens including total coliforms, Escherichia coli, Salmonella and Shigella spp., Campylobacter jejuni, Aeromonas hydrophila, Legionella pneumophila, Vibrio cholerae, Yersinia enterocolytica and Mycobacterium avium in both influent and treated waters from the bioreactor. Total bacteria decreased during FBBR treatment. E. coli, Salmonella and Shigella spp., C. jejuni, …

Phylogeny And Cryptic Diversity In Geckos (Phyllopezus; Phyllodactylidae; Gekkota) From South America’S Open Biomes, Tony Gamble, Guarino R. Colli, Miguel T. Rodrigues, Fernanda P. Werneck, Andrew M. Simons

Biological Sciences Faculty Research and Publications

The gecko genus Phyllopezus occurs across South America’s open biomes: Cerrado, Seasonally Dry Tropical Forests (SDTF, including Caatinga), and Chaco. We generated a multi-gene dataset and estimated phylogenetic relationships among described Phyllopezus taxa and related species. We included exemplars from both described Phyllopezus pollicaris subspecies, P. p. pollicaris and P. p. przewalskii. Phylogenies from the concatenated data as well as species trees constructed from individual gene trees were largely congruent. All phylogeny reconstruction methods showed Bogertia lutzae as the sister species of Phyllopezus maranjonensis, rendering Phyllopezus paraphyletic. We synonymized the monotypic genus Bogertia with Phyllopezus to maintain a …

Lianas Have A Greater Competitive Effect Than Trees Of Similar Biomass On Tropical Canopy Trees, Michael F. Tobin, Alexandra Wright, Scott A. Mangan, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

Lianas (woody vines) reduce growth and survival of host trees in both temperate and tropical forests; however, the relative strength of liana‐tree competition in comparison to tree‐tree competition remains unexplored. When controlling for biomass, lianas may have greater competitive effects than trees because the unique morphology of lianas allows them to reach the forest canopy at relatively small stem diameters and deploy a substantial crown above their host. We tested the hypothesis that lianas have a greater negative effect on canopy trees than do trees of similar biomass with a liana‐ and tree sapling‐cutting experiment in a seasonal tropical moist …

Ornithine Decarboxylase Mrna Is Stabilized In An Mtorc1-Dependent Manner In Ras-Transformed Cells, Sofia Origanti, Shannon L. Nowotarski, Theresa D. Carr, Suzanne Sass-Kuhn, Lan Xiao, Jian-Ying Wang, Lisa M. Shantz

Biological Sciences Faculty Research and Publications

Upon Ras activation, ODC (ornithine decarboxylase) is markedly induced, and numerous studies suggest that ODC expression is controlled by Ras effector pathways. ODC is therefore a potential target in the treatment and prevention of Ras-driven tumours. In the present study we compared ODC mRNA translation profiles and stability in normal and Ras12V-transformed RIE-1 (rat intestinal epithelial) cells. While translation initiation of ODC increased modestly in Ras12V cells, ODC mRNA was stabilized 8-fold. Treatment with the specific mTORC1 [mTOR (mammalian target of rapamycin) complex 1] inhibitor rapamycin or siRNA (small interfering RNA) knockdown of mTOR destabilized the ODC mRNA, but rapamycin …

The Changes Of [Ca2+] In Sr And Ca2+ Release Flux During Fatiguing Activation Of Mouse Skeletal Muscle Fibers, Carlo Manno, Marisilius Mues, Robert H. Fitts, Oliver Griesbeck, Eduardo Rios

Biological Sciences Faculty Research and Publications

No abstract provided.

Levels Of CaV1.2 L-Type Ca2+ Channels Peak In The First Two Weeks In Rat Hippocampus Whereas CaV1.3 Channels Steadily Increase Through Development, Audra A. Kramer, Nicholas E. Ingraham, Emily J. Sharpe, Michelle Mynlieff

Biological Sciences Faculty Research and Publications

Influx of calcium through voltage-dependent channels regulates processes throughout the nervous system. Specifically, influx through L-type channels plays a variety of roles in early neuronal development and is commonly modulated by G-protein-coupled receptors such as GABA_B receptors. Of the four isoforms of L-type channels, only Ca_v1.2 and Ca_v1.3 are predominately expressed in the nervous system. Both isoforms are inhibited by the same pharmacological agents, so it has been difficult to determine the role of specific isoforms in physiological processes. In the present study, Western blot analysis and confocal microscopy were utilized to study developmental expression …

Rna Unwinding By The Trf4/Air2/Mtr4 Polyadenylation (Tramp) Complex, Huijue Jia, Xuying Wang, James T. Anderson, Eckhard Jankowsky

Biological Sciences Faculty Research and Publications

Many RNA-processing events in the cell nucleus involve the Trf4/Air2/Mtr4 polyadenylation (TRAMP) complex, which contains the poly(A) polymerase Trf4p, the Zn-knuckle protein Air2p, and the RNA helicase Mtr4p. TRAMP polyadenylates RNAs designated for processing by the nuclear exosome. In addition, TRAMP functions as an exosome cofactor during RNA degradation, and it has been speculated that this role involves disruption of RNA secondary structure. However, it is unknown whether TRAMP displays RNA unwinding activity. It is also not clear how unwinding would be coordinated with polyadenylation and the function of the RNA helicase Mtr4p in modulating poly(A) addition. Here, we show …

Structure Of Mandelate Racemase With Bound Intermediate Analogues Benzohydroxamate And Cupferron, Adam D. Lietzan, Mitesh Nagar, Elisa Pellmann, Jennifer R. Bourque, Stephen L. Bearne, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Mandelate racemase (MR, EC 5.1.2.2) from Pseudomonas putida catalyzes the Mg2+-dependent interconversion of the enantiomers of mandelate, stabilizing the altered substrate in the transition state by 26 kcal/mol relative to the substrate in the ground state. To understand the origins of this binding discrimination, we determined the X-ray crystal structures of wild-type MR complexed with two analogues of the putative aci-carboxylate intermediate, benzohydroxamate and Cupferron, to 2.2-Å resolution. Benzohydroxamate is shown to be a reasonable mimic of the transition state and/or intermediate because its binding affinity for 21 MR variants correlates well with changes in the free energy of transition …

Developmental Expression Of Drop-Dead Is Required For Early Adult Survival And Normal Body Mass In Drosophila Melanogaster, Christine Lynn Sansone, Edward M. Blumenthal

Biological Sciences Faculty Research and Publications

In Drosophila melanogaster, mutations in the gene drop-dead (drd) result in early adult lethality, with flies dying within 2 weeks of eclosion. Additional phenotypes include neurodegeneration, tracheal defects, starvation, reduced body mass, and female sterility. The cause of early lethality and the function of the drd protein remain unknown. In the current study, the temporal profiles of drd expression required for adult survival and body mass regulation were investigated. Knockdown of drd expression by UAS-RNAi transgenes and rescue of drd expression on a drd mutant background by a UAS-drd transgene were controlled with the Heat Shock Protein …

Perturbing Microtubule Integrity Blocks Amp-Activated Protein Kinase-Induced Meiotic Resumption In Cultured Mouse Oocytes, Ru Ya, Stephen M. Downs

Biological Sciences Faculty Research and Publications

The oocyte meiotic spindle is comprised of microtubules (MT) that bind chromatin and regulate both metaphase plate formation and karyokinesis during meiotic maturation; however, little information is known about their role in meiosis reinitiation. This study was conducted to determine if microtubule integrity is required for meiotic induction and to ascertain how it affects activation of AMP-activated protein kinase (AMPK), an important participant in the meiotic induction process. Treatment with microtubule-disrupting agents nocodazole and vinblastine suppressed meiotic resumption in a dose-dependent manner in both arrested cumulus cell-enclosed oocytes (CEO) stimulated with follicle-stimulating hormone (FSH) and arrested denuded oocytes (DO) stimulated …

The Versatile Molecular Complex Component Lc8 Promotes Several Distinct Steps Of Flagellar Assembly, Anjali Gupta, Dennis R. Diener, Priyanka Sivadas, Joel L. Rosenbaum, Pinfen Yang

Biological Sciences Faculty Research and Publications

LC8 is present in various molecular complexes. However, its role in these complexes remains unclear. We discovered that although LC8 is a subunit of the radial spoke (RS) complex in Chlamydomonas flagella, it was undetectable in the RS precursor that is converted into the mature RS at the tip of elongating axonemes. Interestingly, LC8 dimers bound in tandem to the N-terminal region of a spoke phosphoprotein, RS protein 3 (RSP3), that docks RSs to axonemes. LC8 enhanced the binding of RSP3 N-terminal fragments to purified axonemes. Likewise, the N-terminal fragments extracted from axonemes contained LC8 and putative spoke-docking proteins. Lastly, …

A Flagellar A-Kinase Anchoring Protein With Two Amphipathic Helices Forms A Structural Scaffold In The Radial Spoke Complex, Priyanka Sivadas, Jennifer M. Dienes, Martin St. Maurice, William D. Meek, Pinfen Yang

Biological Sciences Faculty Research and Publications

A-kinase anchoring proteins (AKAPs) contain an amphipathic helix (AH) that binds the dimerization and docking (D/D) domain, RIIa, in cAMP-dependent protein kinase A (PKA). Many AKAPs were discovered solely based on the AH–RIIa interaction in vitro. An RIIa or a similar Dpy-30 domain is also present in numerous diverged molecules that are implicated in critical processes as diverse as flagellar beating, membrane trafficking, histone methylation, and stem cell differentiation, yet these molecules remain poorly characterized. Here we demonstrate that an AKAP, RSP3, forms a dimeric structural scaffold in the flagellar radial spoke complex, anchoring through two distinct AHs, the RIIa …

Inhibitory Effects Of Arabidopsis Earli1 Against Botrytis Cinerea And Bradysia Difformis, Zhen Du, Dan Xu, Lan Li, Yao Shi, Michael Schläppi, Zi-Qin Xu

Biological Sciences Faculty Research and Publications

The aim of this study is to understand the function of EARLI1 in plants subjected to different biotic stresses using EARLI1 overexpressing (OX) and T-DNA knockout (KO) transgenic Arabidopsis lines. Higher levels of expression of EARLI1 in OX lines were confirmed by RT-PCR and Northern blot analysis. The full-length EARLI1 mRNA could not be detected by RT-PCR in KO lines, while only a shorter transcript could be found by RNA gel blotting. In wild-type Col-0 plants (Wt), EARLI1 could be induced by Botrytis cinerea and H₂O₂, indicating this gene might be involved in plant defense system …

Roles Of Arg427 And Arg472 In The Binding And Allosteric Effects Of Acetyl Coa In Pyruvate Carboxylase, Abdussalam Adina-Zada, Chutima Sereerukb, Sarawut Jitrapakdee, Tonya N. Zeczycki, Martin St. Maurice, W. Wallace Cleland, John C. Wallace, Paul V. Attwood

Biological Sciences Faculty Research and Publications

Mutation of Arg427 and Arg472 in Rhizobium etli pyruvate carboxylase to serine or lysine greatly increased the activation constant (K_a) of acetyl CoA, with the increase being greater for the Arg472 mutants. These results indicate that while both these residues are involved in the binding of acetyl CoA to the enzyme, Arg472 is more important than Arg427. The mutations had substantially smaller effects on the k_cat for pyruvate carboxylation. Part of the effects of the mutations was to increase the K_m for MgATP and the K_a for activation by free Mg²⁺ determined at …

The Tree Biodiversity Network (Biotree-Net): Prospects For Biodiversity Research And Conservation In The Neotropics, Luis Cayuela, Lucía Gálvez-Bravo, Ramón Pérez Pérez, Fábio S. De Albuquerque, Duncan J. Golicher, Rakan A. Zahawi, Neptalí Ramírez-Marcial, Cristina Garibaldi, Richard Field, José M. Rey Benayas, Mario González-Espinosa, Patricia Balvanera, Miguel Ángel Casto;;P, Blanca L. Figueroa-Rangel, Daniel M. Griffith, Gerald A. Islebe, Daniel L. Kelly, Miguel Olvera-Vargas, Stefan A. Schnitzer, Eduardo Velázquez, Guadalupe Williams-Linera, Steven W. Brewer, Angélica Camacho-Cruz, Indiana Coronado, Ben De Jong, Íñigo Granzow-De La Cerda, Javier Fernández, William Fonseca, Luis Galindo-Jaimes, Thomas W. Gillespie, Benigno González-Rivas, James E. Gordon, Johanna Hurtado, José Linares, Susan G. Letcher, Scott A. Mangan, Jorge A. Meave, Ernesto V. Méndez, Victor Meza, Susana Ochoa-Gaona, Chris J. Peterson, Viviana Ruiz-Gutierrez, Kymberley A. Snarr, Fernando Tun Dzul, Mirna Valdez-Hernández, Karin M. Viergever, David A. White, John N. Williams, Francisco J. Bonet, Regino Zamora

Biological Sciences Faculty Research and Publications

Biodiversity research and conservation efforts in the tropics are hindered by the lack of knowledge of the assemblages found there, with many species undescribed or poorly known. Our initiative, the Tree Biodiversity Network (BIOTREE-NET), aims to address this problem by assembling georeferenced data from a wide range of sources, making these data easily accessible and easily queried, and promoting data sharing. The database (GIVD ID NA-00-002) currently comprises ca. 50,000 tree records of ca. 5,000 species (230 in the IUCN Red List) from >2,000 forest plots in 11 countries. The focus is on trees because of their pivotal role in …

La Red Internacional De Inventarios Forestales (Biotree-Net) En Mesoamérica: Avances, Retos Y Perspectivas Futuras, Luis Cayuela, Lucía Gálvez-Bravo, F S. De Albuquerque, Duncan J. Golicher, Mario González-Espinosa, Neptalí Ramírez-Marcial, José M. Rey Benayas, Rakan A. Zahawi, Jorge A. Meave, B. M. Benito, Cristina Garibaldi, I. Chan, Ramón Pérez Pérez, Richard Field, Patricia Balvanera, M. A. Castillo, Blanca L. Figueroa-Rangel, Daniel M. Griffith, Gerald A. Islebe, D. L. Kelly, Miguel Olvera-Vargas, Stefan A. Schnitzer, E. Velazquez, Guadalupe Williams-Linera, Steven W. Brewer, Angélica Camacho-Cruz, Indiana Coronado, Ben De Jong, R. Del Castillo, I. Granzowde La Cerda, Javier Fernández, William Fonseca, Luis Galindo-Jaimes, Thomas W. Gillespie, Benigno González-Rivas, J. E. Gordon, Johanna Hurtado, José Linares, Susan G. Letcher, Scott A. Mangan, V. E. Méndez, Victor Meza, Susana Ochoa-Gaona, C. J. Peterson, Viviana Ruiz-Gutierrez, Kymberley A. Snarr, Fernando Tun Dzul, Mirna Valdez-Hernández, Karin M. Viergever, D. A. White, J. N. Williams, Francisco J. Bonet, Regino Zamora

Biological Sciences Faculty Research and Publications

Conservation efforts in Neotropical regions are often hindered by lack of data, since for many species there is a vacuum of information, and many species have not even been described yet. The International Network of Forest Inventory Plots (BIOTREE-NET) gathers and facilitates access to tree data from forest inventory plots in Mesoamerica, while encouraging data exchange between researchers, managers and conservationists. The information is organised and standardised into a single database that includes spatially explicit data. This article describes the scope and objectives of the network, its progress, and the challenges and future perspectives. The database includes above 50000 tree …

Detection Of Mutant-Huntingtin Aggregation Conformers And Modulation Of Sds-Soluble Fibrillar Oligomers By Small Molecules, Emily M. Sontag, Gregor P. Lotz, Goucheng Yang, Christopher J. Sontag, Brian J. Cummings, Charles G. Glabe, Paul J. Muchowski, Leslie Michels Thompson

Biological Sciences Faculty Research and Publications

The Huntington's disease (HD) mutation leads to a complex process of Huntingtin (Htt) aggregation into multimeric species that eventually form visible inclusions in cytoplasm, nuclei and neuronal processes. One hypothesis is that smaller, soluble forms of amyloid proteins confer toxic effects and contribute to early cell dysfunction. However, analysis of mutant Htt aggregation intermediates to identify conformers that may represent toxic forms of the protein and represent potential drug targets remains difficult. We performed a detailed analysis of aggregation conformers in multiple in vitro, cell and ex vivo models of HD. Conformation-specific antibodies were used to identify and characterize aggregation …

Flexibility In The Patterning And Control Of Axial Locomotor Networks In Lamprey, James T. Buchanan

Biological Sciences Faculty Research and Publications

In lower vertebrates, locomotor burst generators for axial muscles generally produce unitary bursts that alternate between the two sides of the body. In lamprey, a lower vertebrate, locomotor activity in the axial ventral roots of the isolated spinal cord can exhibit flexibility in the timings of bursts to dorsally-located myotomal muscle fibers versus ventrally-located myotomal muscle fibers. These episodes of decreased synchrony can occur spontaneously, especially in the rostral spinal cord where the propagating body waves of swimming originate. Application of serotonin, an endogenous spinal neurotransmitter known to presynaptically inhibit excitatory synapses in lamprey, can promote decreased synchrony of dorsal–ventral …

A New Genus Of Miniaturized And Pug-Nosed Gecko From South America (Sphaerodactylidae: Gekkota), Tony Gamble, Juan D. Daza, Guarino R. Colli, Laurie J. Vitt, Aaron M. Bauer

Biological Sciences Faculty Research and Publications

Sphaerodactyl geckos comprise five genera distributed across Central and South America and the Caribbean. We estimated phylogenetic relationships among sphaerodactyl genera using both separate and combined analyses of seven nuclear genes. Relationships among genera were incongruent at different loci and phylogenies were characterized by short, in some cases zero-length, internal branches and poor phylogenetic support at most nodes. We recovered a polyphyletic Coleodactylus, with Coleodactylus amazonicus being deeply divergent from the remaining Coleodactylus species sampled. The C. amazonicus lineage possessed unique codon deletions in the genes PTPN₁₂ and RBMX while the remaining Coleodactylus species had unique codon …