Life Sciences Commons^™

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 …

Effects Of Lightning On Trees: A Predictive Model Based On In Situ Electrical Resistivity, Evan M. Gora, Phillip M. Bitzer, Jeffrey C. Burchfield, Stefan A. Schnitzer, Stephen P. Yanoviak

Biological Sciences Faculty Research and Publications

The effects of lightning on trees range from catastrophic death to the absence of observable damage. Such differences may be predictable among tree species, and more generally among plant life history strategies and growth forms. We used field‐collected electrical resistivity data in temperate and tropical forests to model how the distribution of power from a lightning discharge varies with tree size and identity, and with the presence of lianas. Estimated heating density (heat generated per volume of tree tissue) and maximum power (maximum rate of heating) from a standardized lightning discharge differed 300% among tree species. Tree size and morphology …

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

Biological Sciences Faculty Research and Publications

No abstract provided.

Monitoring Replication Protein A (Rpa) Dynamics In Homologous Recombination Through Site-Specific Incorporation Of Non-Canonical Amino Acids, Nilisha Pokhrel, Sofia Origanti, Eric Parker Davenport, Disha M. Gandhi, Kyle Kaniecki, Ryan A. Mehl, Eric C. Greene, Chris Dockendorff, Edwin Antony

Biological Sciences Faculty Research and Publications

An essential coordinator of all DNA metabolic processes is Replication Protein A (RPA). RPA orchestrates these processes by binding to single-stranded DNA (ssDNA) and interacting with several other DNA binding proteins. Determining the real-time kinetics of single players such as RPA in the presence of multiple DNA processors to better understand the associated mechanistic events is technically challenging. To overcome this hurdle, we utilized non-canonical amino acids and bio-orthogonal chemistry to site-specifically incorporate a chemical fluorophore onto a single subunit of heterotrimeric RPA. Upon binding to ssDNA, this fluorescent RPA (RPAf) generates a quantifiable change in fluorescence, thus serving as …

Trees As Islands: Canopy Ant Species Richness Increases With The Size Of Liana-Free Trees In A Neotropical Forest, Benjamin J. Adams, Stefan A. Schnitzer, Stephen P. Yanoviak

Biological Sciences Faculty Research and Publications

The physical characteristics of habitats shape local community structure; a classic example is the positive relationship between the size of insular habitats and species richness. Despite the high density and proximity of tree crowns in forests, trees are insular habitats for some taxa. Specifically, crown isolation (i.e. crown shyness) prevents the movement of small cursorial animals among trees. Here, we tested the hypothesis that the species richness of ants (S_a) in individual, isolated trees embedded within tropical forest canopies increases with tree size. We predicted that this pattern disappears when trees are connected by lianas (woody vines) or …

Ventricular Action Potential Adaptation To Regular Exercise: Role Of Β-Adrenergic And KAtp Channel Function, Xinrui Wang, Robert H. Fitts

Biological Sciences Faculty Research and Publications

Regular exercise training is known to affect the action potential duration (APD) and improve heart function, but involvement of β-adrenergic receptor (β-AR) subtypes and/or the ATP-sensitive K⁺ (K_ATP) channel is unknown. To address this, female and male Sprague-Dawley rats were randomly assigned to voluntary wheel-running or control groups; they were anesthetized after 6–8 wk of training, and myocytes were isolated. Exercise training significantly increased APD of apex and base myocytes at 1 Hz and decreased APD at 10 Hz. Ca²⁺ transient durations reflected the changes in APD, while Ca²⁺ transient amplitudes were unaffected by wheel …

A Leptin-Regulated Circuit Controls Glucose Mobilization During Noxious Stimuli, Jonathan N. Flak, Deanna M. Arble, Warren Pan, Christa Patterson, Thomas Lanigan, Paulette B. Goforth, Jamie Sackner, Maja Joosten, Donald A. Morgan, Margaret B. Allison, John Hayes, Eva Feldman, Randy J. Seeley, David P. Olson, Kamal Rahmouni, Martin G. Myers Jr.

Biological Sciences Faculty Research and Publications

Adipocytes secrete the hormone leptin to signal the sufficiency of energy stores. Reductions in circulating leptin concentrations reflect a negative energy balance, which augments sympathetic nervous system (SNS) activation in response to metabolically demanding emergencies. This process ensures adequate glucose mobilization despite low energy stores. We report that leptin receptor–expressing neurons (LepRb neurons) in the periaqueductal gray (PAG), the largest population of LepRb neurons in the brain stem, mediate this process. Application of noxious stimuli, which often signal the need to mobilize glucose to support an appropriate response, activated PAG LepRb neurons, which project to and activate parabrachial nucleus (PBN) …

The Discovery Of Xy Sex Chromosomes In A Boa And Python, Tony Gamble, Todd A. Castoe, Stuart V. Nielsen, Jason L. Banks, Daren C. Card, Drew R. Schield, Gordon W. Schuett, Warren Booth

Biological Sciences Faculty Research and Publications

For over 50 years, biologists have accepted that all extant snakes share the same ZW sex chromosomes derived from a common ancestor [1, 2, 3], with different species exhibiting sex chromosomes at varying stages of differentiation. Accordingly, snakes have been a well-studied model for sex chromosome evolution in animals [1, 4]. A review of the literature, however, reveals no compelling support that boas and pythons possess ZW sex chromosomes [2, 5]. Furthermore, phylogenetic patterns of facultative parthenogenesis in snakes and a sex-linked color mutation in the ball python (Python regius) are best explained by boas …

The Noncanonical Roles Of Two Primordial Molecules In Flagella, Xiaoyan Zhu

Dissertations (1934 -)

Motile cilia and flagella are ancient organelles that eukaryotic organisms today still rely on to thrive in their natural environment. Not surprisingly, accumulated evidence has shown that the intricate motility machinery, the microtubule-based axoneme, is evolutionarily conserved down to the molecular level. This notion is epitomized by the signature axonemal complex, the radial spoke (RS). The RS is part of a control center conferring the high frequency and tightly regulated movement. Key RS proteins discovered in biflagellate green alga, Chlamydomonas reinhardtii, are also generated by nearly all ciliated organisms, including Homo sapiens. Among them are two subunits from primordial protein …

Blurred Lines Between Competition And Parasitism, Tara E. Stewart, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

Accurately describing the ecological relationships between species is more than mere semantics-doing so has profound practical and applied implications, not the least of which is that inaccurate descriptions can lead to fundamentally incorrect predicted outcomes of community composition and functioning. Accurate ecological classifications are particularly important in the context of global change, where species interactions can change rapidly following shifts in species composition. Here, we argue that many common ecological interactions-particularly competition and parasitism-can be easily confused and that we often lack empirical evidence for the full reciprocal interaction among species. To make our case and to propose a theoretical …

Assessment Of Five Chilling Tolerance Traits And Gwas Mapping In Rice Using The Usda Mini-Core Collection, Michael Schläppi, Aaron K. Jackson, Georgia C. Eizenga, Aiju Wang, Chengcai Chu, Yao Shi, Naoki Shimoyama, Debbie L. Boykin

Biological Sciences Faculty Research and Publications

Rice (Oryza sativa L.) is often exposed to cool temperatures during spring planting in temperate climates. A better understanding of genetic pathways regulating chilling tolerance will enable breeders to develop varieties with improved tolerance during germination and young seedling stages. To dissect chilling tolerance, five assays were developed; one assay for the germination stage, one assay for the germination and seedling stage, and three for the seedling stage. Based on these assays, five chilling tolerance indices were calculated and assessed using 202 O. sativa accessions from the Rice Mini-Core (RMC) collection. Significant differences between RMC accessions made the five …

Mechanisms And Functions Of Spatial Protein Quality Control, Emily M. Sontag, Rahul S. Samant, Judith Frydman

Biological Sciences Faculty Research and Publications

A healthy proteome is essential for cell survival. Protein misfolding is linked to a rapidly expanding list of human diseases, ranging from neurodegenerative diseases to aging and cancer. Many of these diseases are characterized by the accumulation of misfolded proteins in intra- and extracellular inclusions, such as amyloid plaques. The clear link between protein misfolding and disease highlights the need to better understand the elaborate machinery that manages proteome homeostasis, or proteostasis, in the cell. Proteostasis depends on a network of molecular chaperones and clearance pathways involved in the recognition, refolding, and/or clearance of aberrant proteins. Recent studies reveal that …

Functional Analysis Of Microrna Pathway Genes In The Somatic Gonad And Germ Cells During Ovulation In C. Elegans, Carmela Rios, David Warren, Benjamin Olson, Allison L. Abbott

Biological Sciences Faculty Research and Publications

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression that play critical roles in animal development and physiology, though functions for most miRNAs remain unknown. Worms with reduced miRNA biogenesis due to loss of Drosha or Pasha/DGCR8 activity are sterile and fail to ovulate, indicating that miRNAs are required for the process of oocyte maturation and ovulation. Starting with this penetrant sterile phenotype and using new strains created to perform tissue specific RNAi, we characterized the roles of the C. elegans Pasha, pash-1, and two miRNA-specific Argonautes, alg-1 and alg-2, in somatic gonad cells and in germ cells in the regulation …

Skeletal Muscle Pgc-1Β Signaling Is Sufficient To Drive An Endurance Exercise Phenotype And To Counteract Components Of Detraining In Mice, Samuel Lee, Teresa C. Leone, Lisa Rogosa, John Rumsey, Julio Ayala, Paul M. Coen, Robert H. Fitts, Rick B. Vega, Daniel P. Kelly

Biological Sciences Faculty Research and Publications

Peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α and -1β serve as master transcriptional regulators of muscle mitochondrial functional capacity and are capable of enhancing muscle endurance when overexpressed in mice. We sought to determine whether muscle-specific transgenic overexpression of PGC-1β affects the detraining response following endurance training. First, we established and validated a mouse exercise-training-detraining protocol. Second, using multiple physiological and gene expression end points, we found that PGC-1β overexpression in skeletal muscle of sedentary mice fully recapitulated the training response. Lastly, PGC-1β overexpression during the detraining period resulted in partial prevention of the detraining response. Specifically, an increase in the plateau …

Repeated Evolution Of Digital Adhesion In Geckos: A Reply To Harrington And Reeder, Tony Gamble, E. Greenbaum, T. R. Jackman, A. P. Russell, A. M. Bauer

Biological Sciences Faculty Research and Publications

We published a phylogenetic comparative analysis that found geckos had gained and lost adhesive toepads multiple times over their long evolutionary history (Gamble et al., PLoS One, 7, 2012, e39429). This was consistent with decades of morphological studies showing geckos had evolved adhesive toepads on multiple occasions and that the morphology of geckos with ancestrally padless digits can be distinguished from secondarily padless forms. Recently, Harrington & Reeder (J. Evol. Biol., 30, 2017, 313) reanalysed data from Gamble et al. (PLoS One, 7, 2012, e39429) and found little support for the multiple origins hypothesis. Here, we …

Reductions In Mesolimbic Dopamine Signaling And Aversion: Implications For Relapse And Learned Avoidance, Mykel A. Robble

Dissertations (1934 -)

The ability to adjust behavior appropriately following an aversive experience is essential for survival, yet variability in this process contributes to a wide range of disorders, including drug addiction. It is clear that proper approach and avoidance is regulated, in part, by the activity of the mesolimbic dopamine system. While the importance of this system as a critical modulator of reward learning has been extensively characterized, its involvement in directing aversion-related behaviors and learning is still poorly understood. Recent studies have revealed that aversive stimuli and their predictors cause rapid reductions in nucleus accumbens (NAc) dopamine concentrations. Furthermore, a normally …

Mutational Analysis Of The Qrrq Motif In The Yeast Hig1 Type 2 Protein Rcf1 Reveals A Regulatory Role For The Cytochrome C Oxidase Complex, Joshua Garlich, Valentina Strecker, Ilka Wittig, Rosemary A. Stuart

Biological Sciences Faculty Research and Publications

The yeast Rcf1 protein is a member of the conserved family of proteins termed the hypoxia-induced gene (domain) 1 (Hig1 or HIGD1) family. Rcf1 interacts with components of the mitochondrial oxidative phosphorylation system, in particular the cytochrome bc₁(complex III)-cytochrome c oxidase (complex IV) supercomplex (termed III-IV) and the ADP/ATP carrier proteins. Rcf1 plays a role in the assembly and modulation of the activity of complex IV; however, the molecular basis for how Rcf1 influences the activity of complex IV is currently unknown. Hig1 type 2 isoforms, which include the Rcf1 protein, are characterized in part by the presence …

Loss Of The Rna Helicase Skiv2l2 Impairs Mitotic Progression And Replication-Dependent Histone Mrna Turnover In Murine Cell Lines, Alexis Marie Onderak, James T. Anderson

Biological Sciences Faculty Research and Publications

RNA surveillance via the nuclear exosome requires cofactors such as the helicase SKIV2L2 to process and degrade certain noncoding RNAs. This research aimed to characterize the phenotype associated with RNAi knockdown of Skiv2l2 in two murine cancer cell lines: Neuro2A and P19. SKIV2L2 depletion in Neuro2A and P19 cells induced changes in gene expression indicative of cell differentiation and reduced cellular proliferation by 30%. Propidium iodide-based cell-cycle analysis of Skiv2l2 knockdown cells revealed defective progression through the G2/M phase and an accumulation of mitotic cells, suggesting SKIV2L2 contributes to mitotic progression. Since SKIV2L2 targets RNAs to the nuclear exosome for …

De Novo [Psi+] Prion Formation Involves Multiple Pathways To Form Infectious Oligomers, Jaya Sharma, Grett T. Wisniewski, Emily Paulson, Joanna O. Obaoye, Stephen J. Merrill, Anita L. Manogaran

Biological Sciences Faculty Research and Publications

Prion and other neurodegenerative diseases are associated with misfolded protein assemblies called amyloid. Research has begun to uncover common mechanisms underlying transmission of amyloids, yet how amyloids form in vivo is still unclear. Here, we take advantage of the yeast prion, [PSI ⁺], to uncover the early steps of amyloid formation in vivo. [PSI ⁺] is the prion form of the Sup35 protein. While [PSI ⁺] formation is quite rare, the prion can be greatly induced by overexpression of the prion domain of the Sup35 protein. This de novo induction of [PSI …

Two Adjacent Phenylalanines In The Nmda Receptor Glun2a Subunit M3 Domain Interactively Regulate Alcohol Sensitivity And Ion Channel Gating, Hong Ren, Yulin Zhao, Man Wu, Donard S. Dwyer, Robert W. Peoples

Biological Sciences Faculty Research and Publications

The N-methyl-d-aspartate (NMDA) receptor is a key target of ethanol action in the central nervous system. Alcohol inhibition of NMDA receptor function involves small clusters of residues in the third and fourth membrane-associated (M) domains. Previous results from this laboratory have shown that two adjacent positions in the M3 domain, F636 and F637, can powerfully regulate alcohol sensitivity and ion channel gating. In this study, we report that these positions interact with one another in the regulation of both NMDA receptor gating and alcohol action. Using dual mutant cycle analysis, we detected interactions among various substitution mutants at these …

On The Origin Of Frictional Adhesion In Geckos: Small Morphological Changes Lead To A Major Biomechanical Transition In The Genus Gonatodes, Timothy E. Higham, Tony Gamble, Anthony P. Russell

Biological Sciences Faculty Research and Publications

The evolutionary history of vertebrate locomotion is punctuated by innovations that have permitted expansion into novel ecological niches. Frictional adhesion of geckos is an innovation renowned for enabling locomotion on vertical and inverted smooth surfaces. Much is known about the microstructure and function of the fully-expressed gekkotan adhesive apparatus, although how it originated is poorly understood. Therefore, identifying species that exhibit the earliest stages of expression of frictional adhesion will provide significant insights into the evolution of this trait. Our previous investigation of digital proportions, shape, scalation, skeletal form, and subdigital epidermal micro-ornamentation in the genus Gonatodes led us to …

Physiological Regulation And Efficient Xylem Water Transport Regulate Diurnal Water And Carbon Balances Of Tropical Lianas, Ya-Jun Chen, Stefan A. Schnitzer, Yongg-Jiang Zhang, Ze-Xin Fan, Guillermo Goldstein, Kyle W. Tomlinson, Hua Lin, Jiao-Lin Zhang, Kun-Fang Cao

Biological Sciences Faculty Research and Publications

No abstract provided.

Calsequestrin Depolymerizes When Calcium Is Depleted In The Sarcoplasmic Reticulum Of Working Muscle, Carlo Manno, Lourdes Figueroa, Dirk Gillespie, Robert Fitts, Chul-Hee Kang, Clara Franzini-Armstrong, Eduardo Rios

Biological Sciences Faculty Research and Publications

Calsequestrin, the only known protein with cyclical storage and supply of calcium as main role, is proposed to have other functions, which remain unproven. Voluntary movement and the heart beat require this calcium flow to be massive and fast. How does calsequestrin do it? To bind large amounts of calcium in vitro, calsequestrin must polymerize and then depolymerize to release it. Does this rule apply inside the sarcoplasmic reticulum (SR) of a working cell? We answered using fluorescently tagged calsequestrin expressed in muscles of mice. By FRAP and imaging we monitored mobility of calsequestrin as [Ca²⁺] in the …

Network Dynamics Mediate Circadian Clock Plasticity, Abdelhalim Azzi, Jennifer A. Evans, Tanya Leise, Jihwan Myung, Toru Takumi, Alec J. Davidson, Steven A. Brown

Biological Sciences Faculty Research and Publications

A circadian clock governs most aspects of mammalian behavior. Although its properties are in part genetically determined, altered light-dark environment can change circadian period length through a mechanism requiring de novo DNA methylation. We show here that this mechanism is mediated not via cell-autonomous clock properties, but rather through altered networking within the suprachiasmatic nuclei (SCN), the circadian “master clock,” which is DNA methylated in region-specific manner. DNA methylation is necessary to temporally reorganize circadian phasing among SCN neurons, which in turn changes the period length of the network as a whole. Interruption of neural communication by inhibiting neuronal firing …

Identification Of Multiple Functional Receptors For Tyramine On An Insect Secretory Epithelium, Haiying Zhang, Edward M. Blumenthal

Biological Sciences Faculty Research and Publications

The biogenic amine tyramine (TA) regulates many aspects of invertebrate physiology and development. Although three TA receptor subtypes have been identified (TAR1-3), specific receptors have not been linked to physiological responses in native tissue. In the Malpighian (renal) tubule of Drosophila melanogaster, TA activates a transepithelial chloride conductance, resulting in diuresis and depolarization of the transepithelial potential. In the current work, mutation or RNAi-mediated knockdown in the stellate cells of the tubule of TAR2 (tyrR, CG7431) resulted in a dramatic reduction, but not elimination, of the TA-mediated depolarization. Mutation or knockdown of TAR3 (tyrRII, …

Stage-Specific Timing Of The Microrna Regulation Of Lin-28 By The Heterochronic Gene Lin-14 In Caenorhabditis Elegans, Jennifer Tsialikas, Mitchell A. Romens, Allison L. Abbott, Eric G. Moss

Biological Sciences Faculty Research and Publications

In normal development, the order and synchrony of diverse developmental events must be explicitly controlled. In the nematode Caenorhabditis elegans, the timing of larval events is regulated by hierarchy of proteins and microRNAs (miRNAs) known as the heterochronic pathway. These regulators are organized in feedforward and feedback interactions to form a robust mechanism for specifying the timing and execution of cell fates at successive stages. One member of this pathway is the RNA binding protein LIN-28, which promotes pluripotency and cell fate decisions in successive stages. Two genetic circuits control LIN-28 abundance: it is negatively regulated by the miRNA …

Spatial Sequestration And Oligomer Remodeling During De Novo [Psi+] Formation, Douglas Lyke, Anita L. Manogaran

Biological Sciences Faculty Research and Publications

Prions are misfolded, aggregated, infectious proteins found in a range of organisms from mammals to bacteria. In mammals, prion formation is difficult to study because misfolding and aggregation take place prior to symptom presentation. The study of the yeast prion [PSI⁺], which is the misfolded infectious form of Sup35p, provides a tractable system to monitor prion formation in real time. Recently, we showed that the de novo formation of prion aggregates begins with the appearance of highly mobile cytoplasmic foci, called early foci, which assemble into larger ring or dot structures. We also observed SDS-resistant oligomers during …