Life Sciences Commons^™

Morphological Variability In Tree Root Architecture Indirectly Affects Coexistence Among Competitors In The Understory, Erik T. Aschehoug, Ragan M. Callaway

Biological Sciences Faculty Publications

Interactions between plants can have strong effects on community structure and function. Variability in the morphological, developmental, physiological, and biochemical traits of plants can influence the outcome of plant interactions and thus have important ecological consequences. However, the ecological ramifications of trait variability in plants are poorly understood and have rarely been tested in the field. We experimentally tested the effects of morphological variation in root architecture of Quercus douglasii trees in the field on interactions between understory plants and community composition. Our results indicate that variability among Q. douglasii tree root systems initiates a striking reversal in the competitive …

A Quantitative Analysis Of Kalandars And Captive Bears In Pakistan, Thomas P. Rooney, Kendra C. Millam

Biological Sciences Faculty Publications

In 2013, the Bioresource Research Centre (Islamabad, Pakistan) conducted a comprehensive census of the remaining dancing and bear-baiting bears in Pakistan. This involved locating and counting the actual involved bears and bear keepers (kalandars), collecting detailed socio-economic data from the bear-keepers, and identifying attitudes and key drivers behind this livelihood. This report summarizes the findings from the census, reveals relationships in the data that are not immediately apparent, and identifies potential leverage points for ongoing campaign efforts.

Ontogenetic Investigation Of Underwater Hearing Capabilities In Loggerhead Sea Turtles (Caretta Caretta) Using A Dual Testing Approach, Ashley L. Lavender, Soraya M. Bartol, Ian K. Bartol

Biological Sciences Faculty Publications

Sea turtles reside in different acoustic environments with each life history stage and may have different hearing capacity throughout ontogeny. For this study, two independent yet complementary techniques for hearing assessment, i.e. behavioral and electrophysiological audiometry, were employed to (1) measure hearing in post-hatchling and juvenile loggerhead sea turtles Caretta caretta (19-62 cm straight carapace length) to determine whether these migratory turtles exhibit an ontogenetic shift in underwater auditory detection and (2) evaluate whether hearing frequency range and threshold sensitivity are consistent in behavioral and electrophysiological tests. Behavioral trials first required training turtles to respond to known frequencies, a multi-stage, …

Epidemic Surveillance Using An Electronic Medical Record: An Empiric Approach To Performance Improvement, Hongzhang Zheng, Holly Gaff, Gary Smith, Sylvain Delisle

Biological Sciences Faculty Publications

BACKGROUNDS: Electronic medical records (EMR) form a rich repository of information that could benefit public health. We asked how structured and free-text narrative EMR data should be combined to improve epidemic surveillance for acute respiratory infections (ARI).

METHODS: Eight previously characterized ARI case detection algorithms (CDA) were applied to historical EMR entries to create authentic time series of daily ARI case counts (background). An epidemic model simulated influenza cases (injection). From the time of the injection, cluster-detection statistics were applied daily on paired background+injection (combined) and background-only time series. This cycle was then repeated with the injection shifted to each …

Lateral Line Analogue Aids Vision In Successful Predator Evasion For The Brief Squid, Lolliguncula Brevis, Carly A. York, Ian K. Bartol

Biological Sciences Faculty Publications

Cephalopods have visual and mechanoreception systems that may be employed to sense and respond to an approaching predator. While vision presumably plays the dominant role, the importance of the lateral line analogue for predator evasion has not been examined in cephalopods. To test the respective roles of vision and the lateral line analogue, brief squid, Lolliguncula brevis, were observed in the presence of summer flounder, Paralichthys dentatus, under light and dark conditions with their lateral line analogue intact and ablated. Hair cell ablation was achieved through a pharmacological technique used for the first time on a cephalopod. The …

Transcriptome Of The Female Synganglion Of The Black-Legged Tick Ixodes Scapularis (Acari: Ixodidae) With Comparison Between Illumina And 454 Systems, Noble Egekwu, Daniel E. Sonenshine, Brooke W. Bissinger, R. Michael Roe

Biological Sciences Faculty Publications

Illumina and 454 pyrosequencing were used to characterize genes from the synganglion of female Ixodes scapularis. GO term searching success for biological processes was similar for samples sequenced by both methods. However, for molecular processes, it was more successful for the Illumina samples than for 454 samples. Functional assignments of transcripts predicting neuropeptides, neuropeptide receptors, neurotransmitter receptors and other genes of interest was done, supported by strong e-values (<-6), and high consensus sequence alignments. Transcripts predicting 15 putative neuropeptide prepropeptides ((allatostatin, allatotropin, bursicon α, corticotropin releasing factor (CRF), CRF-binding protein, eclosion hormone, FMRFamide, glycoprotein A, insulin-like peptide, ion transport peptide, myoinhibitory peptide, inotocin ( = neurophysin-oxytocin), Neuropeptide F, sulfakinin and SIFamide)) and transcripts predicting receptors for 14 neuropeptides (allatostatin, calcitonin, cardioacceleratory peptide, corazonin, CRF, eclosion hormone, gonadotropin-releasing hormone/AKH-like, insulin-like peptide, neuropeptide F, proctolin, pyrokinin, SIFamide, sulfakinin and tachykinin) are reported. Similar to Dermacentor variabilis, we found transcripts matching pro-protein convertase, essential for converting neuropeptide hormones to their mature form. Additionally, transcripts predicting 6 neurotransmitter/neuromodulator receptors (acetylcholine, GABA, dopamine, glutamate, octopamine and …

Surface Water Inundation In The Boreal-Artic: Potential Impacts On Regional Methane Emissions, J. D. Watts, John S. Kimball, Annett Bartsch, Kyle C. Mcdonald

Biological Sciences Faculty Publications

Northern wetlands may be vulnerable to increased carbon losses from methane (CH₄), a potent greenhouse gas, under current warming trends. However, the dynamic nature of open water inundation and wetting/drying patterns may constrain regional emissions, offsetting the potential magnitude of methane release. Here we conduct a satellite data driven model investigation of the combined effects of surface warming and moisture variability on high northern latitude (45° N) wetland CH₄ emissions, by considering (1) sub-grid scale changes in fractional water inundation (Fw) at 15 day, monthly and annual intervals using 25 km resolution satellite microwave retrievals, and (2) …

Ex Uno Plures: Clonal Reinforcement Drives Evolution Of A Simple Microbial Community, Margie A. Kinnersley, Jared Wenger, Evgueny Kroll, Julian Adams, Gavin Sherlock, Frank Rosenzweig

Biological Sciences Faculty Publications

A major goal of genetics is to define the relationship between phenotype and genotype, while a major goal of ecology is to identify the rules that govern community assembly. Achieving these goals by analyzing natural systems can be difficult, as selective pressures create dynamic fitness landscapes that vary in both space and time. Laboratory experimental evolution offers the benefit of controlling variables that shape fitness landscapes, helping to achieve both goals. We previously showed that a clonal population of E. coli experimentally evolved under continuous glucose limitation gives rise to a genetically diverse community consisting of one clone, CV103, that …

Identification Of Novel Small Rnas And Characterization Of The 6s Rna Of Coxiella Burnetii, Indu Warrier, Linda D. Hicks, James M. Battisti, Rahul Raghavan, Michael F. Minnick

Biological Sciences Faculty Publications

Coxiella burnetii, an obligate intracellular bacterial pathogen that causes Q fever, undergoes a biphasic developmental cycle that alternates between a metabolically-active large cell variant (LCV) and a dormant small cell variant (SCV). As such, the bacterium undoubtedly employs complex modes of regulating its lifecycle, metabolism and pathogenesis. Small RNAs (sRNAs) have been shown to play important regulatory roles in controlling metabolism and virulence in several pathogenic bacteria. We hypothesize that sRNAs are involved in regulating growth and development of C. burnetii and its infection of host cells. To address the hypothesis and identify potential sRNAs, we subjected total RNA …

White-Tailed Deer Are A Biotic Filter During Community Assembly, Reducing Species And Phylogenetic Diversity, Danielle R. Begley-Miller, Andrew L. Hipp, Bethany H. Brown, Marlene Hahn, Thomas P. Rooney

Biological Sciences Faculty Publications

Community assembly entails a filtering process, where species found in a local community are those that can pass through environmental (abiotic) and biotic filters and successfully compete. Previous research has demonstrated the ability of white-tailed deer (Odocoileus virginianus) to reduce species diversity and favour browse-tolerant plant communities. In this study, we expand on our previous work by investigating deer as a possible biotic filter altering local plant community assembly. We used replicated 23-year-old deer exclosures to experimentally assess the effects of deer on species diversity (H′), richness (SR), phylogenetic community structure and phylogenetic diversity in paired …

Spring Hydrology Determines Summer Net Carbon Uptake In Northern Ecosystems, Yonghong Yi, John S. Kimball, Rolf H. Reichle

Biological Sciences Faculty Publications

Increased photosynthetic activity and enhanced seasonal CO₂ exchange of northern ecosystems have been observed from a variety of sources including satellite vegetation indices (such as the normalized difference vegetation index; NDVI) and atmospheric CO₂ measurements. Most of these changes have been attributed to strong warming trends in the northern high latitudes (50° N). Here we analyze the interannual variation of summer net carbon uptake derived from atmospheric CO₂ measurements and satellite NDVI in relation to surface meteorology from regional observational records. We find that increases in spring precipitation and snow pack promote summer net carbon uptake of …

Octopamine Neuromodulation Regulates Gr32a-Linked Aggression And Courtship Pathways In Drosophila Males, Jonathan C. Andrews, Maria Paz Fernàndez, Qin Yu, Gregory Patrick Leary, Adelaine K. W. Leung, Michael P. Kavanaugh, Edward A. Kravitz, Sarah J. Certel

Biological Sciences Faculty Publications

Chemosensory pheromonal information regulates aggression and reproduction in many species, but how pheromonal signals are transduced to reliably produce behavior is not well understood. Here we demonstrate that the pheromonal signals detected by Gr32a-expressing chemosensory neurons to enhance male aggression are filtered through octopamine (OA, invertebrate equivalent of norepinephrine) neurons. Using behavioral assays, we find males lacking both octopamine and Gr32a gustatory receptors exhibit parallel delays in the onset of aggression and reductions in aggression. Physiological and anatomical experiments identify Gr32a to octopamine neuron synaptic and functional connections in the suboesophageal ganglion. Refining the Gr32a-expressing population indicates that mouth Gr32a …

Structure Of A Mitochondrial Cytochrome C Conformer Competent For Peroxidase Activity, Levi J. Mcclelland, Tung-Chung Mou, Margaret E. Jeakins-Cooley, Stephen R. Sprang, Bruce E. Bowler

Biological Sciences Faculty Publications

At the onset of apoptosis, the peroxidation of cardiolipin at the inner mitochondrial membrane by cytochrome c requires an open coordination site on the heme. We report a 1.45-Å resolution structure of yeast iso-1-cytochrome c with the Met80 heme ligand swung out of the heme crevice and replaced by a water molecule. This conformational change requires modest adjustments to the main chain of the heme crevice loop and is facilitated by a trimethyllysine 72-to-alanine mutation. This mutation also enhances the peroxidase activity of iso-1-cytochrome c. The structure shows a buried water channel capable of facilitating peroxide access to the active …

Uncoupling Reproduction From Metabolism Extends Chronological Lifespan In Yeast, Saisubramanian Nagarajan, Arthur L. Kruckeberg, Karen H. Schmidt, Evgueny Kroll, Morgan Hamilton, Kate Mcinnerney, Ryan Summers, Timothy Taylor, Frank Rosenzweig

Biological Sciences Faculty Publications

Studies of replicative and chronological lifespan in Saccharomyces cerevisiae have advanced understanding of longevity in all eukaryotes. Chronological lifespan in this species is defined as the agedependent viability of nondividing cells. To date this parameter has only been estimated under calorie restriction, mimicked by starvation. Because postmitotic cells in higher eukaryotes often do not starve, we developed a model yeast system to study cells as they age in the absence of calorie restriction. Yeast cells were encapsulated in a matrix consisting of calcium alginate to form ~3 mm beads that were packed into bioreactors and fed ad libitum. Under these …

A Satellite Data Driven Biophysical Modeling Approach For Estimating Northern Peatland And Tundra Co2 And Ch4 Fluxes, J. D. Watts, John S. Kimball, F. J. W. Parmentier, T. Sachs, J. Rinne, D. Zona, W. Oechel, T. Tagesson, M. Jackowicz-Korczynski, M. Aurela

Biological Sciences Faculty Publications

The northern terrestrial net ecosystem carbon balance (NECB) is contingent on inputs from vegetation gross primary productivity (GPP) to offset the ecosystem respiration (Reco) of carbon dioxide (CO₂) and methane (CH₄) emissions, but an effective framework to monitor the regional Arctic NECB is lacking. We modified a terrestrial carbon flux (TCF) model developed for satellite remote sensing applications to evaluate wetland CO₂ and CH₄ fluxes over pan-Arctic eddy covariance (EC) flux tower sites. The TCF model estimates GPP, CO2 and CH4 emissions using in situ or remote sensing and reanalysis-based climate data as inputs. …

Inactivation Of Genes For Antigenic Variation In The Relapsing Fever Spirochete Borrelia Hermsii Reduces Infectivity In Mice And Transmission By Ticks, Sandra J. Raffel, James M. Battisti, Robert J. Fischer, Tom G. Schwan

Biological Sciences Faculty Publications

Borrelia hermsii, a causative agent of relapsing fever of humans in western North America, is maintained in enzootic cycles that include small mammals and the tick vector Ornithodoros hermsi. In mammals, the spirochetes repeatedly evade the host’s acquired immune response by undergoing antigenic variation of the variable major proteins (Vmps) produced on their outer surface. This mechanism prolongs spirochete circulation in blood, which increases the potential for acquisition by fast-feeding ticks and therefore perpetuation of the spirochete in nature. Antigenic variation also underlies the relapsing disease observed when humans are infected. However, most spirochetes switch off the bloodstream …

Body Size And Geographic Range Do Not Explain Long Term Variation In Fish Populations: A Bayesian Phylogenetic Approach To Testing Assembly Processes In Stream Fish Assemblages, Stephen J. Jacquemin, Jason C. Doll

Biological Sciences Faculty Publications

We combine evolutionary biology and community ecology to test whether two species traits, body size and geographic range, explain long term variation in local scale freshwater stream fish assemblages. Body size and geographic range are expected to influence several aspects of fish ecology, via relationships with niche breadth, dispersal, and abundance. These traits are expected to scale inversely with niche breadth or current abundance, and to scale directly with dispersal potential. However, their utility to explain long term temporal patterns in local scale abundance is not known. Comparative methods employing an existing molecular phylogeny were used to incorporate evolutionary relatedness …

Darwin’S Diagram Of Divergence Of Taxa As A Causal Model For The Origin Of Species, Juan Luis Bouzat

Biological Sciences Faculty Publications

On the basis that Darwin's theory of evolution encompasses two logically independent processes (common descent and natural selection), the only figure in On the Origin of Species (the Diagram of Divergence of Taxa) is often interpreted as illustrative of only one of these processes: the branching patterns representing common ancestry. Here, I argue that Darwin's Diagram of Divergence of Taxa represents a broad conceptual model of Darwin's theory, illustrating the causal efficacy of natural selection in producing well-defined varieties and ultimately species. The Tree Diagram encompasses the idea that natural selection explains common descent and the origin of organic diversity, …

The Toxavapa Toxin-Antitoxin Locus Contributes To The Survival Of Nontypeable Haemophilus Influenzae During Infection, Dabin Ren, Alexis A. Kordis, Daniel E. Sonenshine, Dayle A. Daines

Biological Sciences Faculty Publications

Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen that is a common cause of acute and recurrent mucosal infections. One uncharacterized NTHi toxin-antitoxin (TA) module, NTHI1912-1913, is a host inhibition of growth (higBA) homologue. We hypothesized that this locus, which we designated toxAvapA, contributed to NTHi survival during infection. We deleted toxAvapA and determined that growth of the mutant in defined media was not different from the parent strain. We tested the mutant for persistence during long-term in vitro co-culture with primary human respiratory tissues, which revealed that the DeltatoxAvapA mutant was attenuated for survival. We then …

Bulk Elastic Moduli And Solute Potentials In Leaves Of Freshwater, Coastal, And Marine Hydrophytes. Are Marine Plants More Rigid?, Brant W. Touchette, Sarah E. Marcus, Emily C. Adams

Biological Sciences Faculty Publications

Bulk modulus of elasticity (ɛ), depicting the flexibility of plant tissues, is recognized as an important component in maintaining internal water balance. Elevated ɛ and comparatively low osmotic potential (Ψ_π) may work in concert to effectively maintain vital cellular water content. This concept, termed the ‘cell water conservation hypothesis’, may foster tolerance for lower soil-water potentials in plants while minimizing cell dehydration and shrinkage. Therefore, the accumulation of solutes in marine plants, causing decreases in Ψ_π, play an important role in plant–water relations and likely works with higher ɛ to achieve favourable cell …

Insights Into The Development And Evolution Of Exaggerated Traits Using De Novo Transcriptomes Of Two Species Of Horned Scarab Beetles, Ian A. Warren, J. Cristobal Vera, Annika Johns, Robert Zinna, James H. Marden, Douglas J. Emlen, Ian Dworkin, Laura C. Lavine

Biological Sciences Faculty Publications

Scarab beetles exhibit an astonishing variety of rigid exo-skeletal outgrowths, known as ‘‘horns’’. These traits are often sexually dimorphic and vary dramatically across species in size, shape, location, and allometry with body size. In many species, the horn exhibits disproportionate growth resulting in an exaggerated allometric relationship with body size, as compared to other traits, such as wings, that grow proportionately with body size. Depending on the species, the smallest males either do not produce a horn at all, or they produce a disproportionately small horn for their body size. While the diversity of horn shapes and their behavioural ecology …

A Broadly Implementable Research Course In Phage Discovery And Genomics For First-Year Undergraduate Students, Tuajuanda C. Jordan, Sandra H. Burnett, Susan Carson, Steven M. Caruso, Karl Clase, Randall J. Dejong, John J. Dennehy, Dee R. Denver, David Dunbar, Sarah C. R. Elgin, Ann M. Findley, Chris R. Gissendanner, Urszula P. Golebiewska, Nancy Guild, Grant A. Hartzog, Wendy H. Grillo, Gail P. Hollowell, Lee E. Hughes, Allison Johnson, Rodney A. King, Lynn O. Lewis T, Wei Li, Frank Rosenzweig, Michael R. Rubin, Margaret S. Saha, James Sandoz, Christopher D. Shaffer, Barbara Taylor, Louise Temple, Edwin Vazquez, Vassie C. Ware, Lucia P. Barker, Kevin W. Bradley, Deborah Jacobs-Sera, Welkin H. Pope, Daniel A. Russell, Steven G. Cresawn, David Lopatto, Cheryl P. Bailey, Graham F. Hatfull

Biological Sciences Faculty Publications

Engaging large numbers of undergraduates in authentic scientific discovery is desirable but difficult to achieve. We have developed a general model in which faculty and teaching assistants from diverse academic institutions are trained to teach a research course for first-year undergraduate students focused on bacteriophage discovery and genomics. The course is situated within a broader scientific context aimed at understanding viral diversity, such that faculty and students are collaborators with established researchers in the field. The Howard Hughes Medical Institute (HHMI) Science Education Alliance Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) course has been widely implemented and has been …

Examining Historical And Current Mixed-Severity Fire Regimes In Ponderosa Pine And Mixed-Conifer Forests Of Western North America, Dennis C. Odion, Chad T. Hanson, Andre Arsenault, William L. Baker, Dominick A. Dellasala, Richard L. Hutto, Walt Klenner, Max A. Moritz, Rosemary L. Sherriff, Thomas T. Veblen, Mark A. Williams

Biological Sciences Faculty Publications

There is widespread concern that fire exclusion has led to an unprecedented threat of uncharacteristically severe fires in ponderosa pine (Pinus ponderosa Dougl. ex. Laws) and mixed-conifer forests of western North America. These extensive montane forests are considered to be adapted to a low/moderate-severity fire regime that maintained stands of relatively old trees. However, there is increasing recognition from landscape-scale assessments that, prior to any significant effects of fire exclusion, fires and forest structure were more variable in these forests. Biota in these forests are also dependent on the resources made available by higher-severity fire. A better understanding of …

Host Specificity And Co-Speciation In Avian Haemosporidia In The Western Cape, South Africa, Sharon Okanga, Graeme S. Cumming, Philip A.R. Hockey, Lisa Nupen, Jeffrey L. Peters

Biological Sciences Faculty Publications

Host and pathogen ecology are often closely linked, with evolutionary processes often leading to the development of host specificity traits in some pathogens. Host specificity may range from ‘generalist’, where pathogens infect any available competent host; to ‘specialist’, where pathogens repeatedly infect specific host species or families. Avian malaria ecology in the region remains largely unexplored, despite the presence of vulnerable endemic avian species. We analysed the expression of host specificity in avian haemosporidia, by applying a previously developed host specificity index to lineages isolated from wetland passerines in the Western Cape, South Africa. Parasite lineages were isolated using PCR …

Invasive Plant Erodes Local Song Diversity In A Migratory Passerine, Yvette K. Ortega, Aubree Benson, Erick Greene

Biological Sciences Faculty Publications

Exotic plant invasions threaten ecosystems globally, but we still know little about the specific consequences for animals. Invasive plants can alter the quality of breeding habitat for songbirds, thereby impacting important demographic traits such as dispersal, philopatry, and age structure. These demographic effects may in turn alter song-learning conditions to affect song structure and diversity. We studied Chipping Sparrows (Spizella passerina) breeding in six savannas that were either dominated by native vegetation or invaded by spotted knapweed (Centaurea stoebe), an exotic forb known to diminish food resources and reproductive success. Here, we report that the prevalence of older birds was …

Temperature, Hypoxia, And Mycobacteriosis: Effects On Adult Striped Bass Morone Saxatilis Metabolic Performance, Dominique Lapointe, Wolfgang K. Vogelbein, Mary C. Fabrizio, David T. Gauthier, Richard W. Brill

Biological Sciences Faculty Publications

Mycobacteriosis, a chronic bacterial disease of fishes, is prevalent in adult striped bass from Chesapeake Bay (USA). Although environmental factors may play a role in disease expression, the interaction between the disease and environmental stress remains unexplored. We therefore examined the individual and interactive effects of elevated temperature, hypoxia, and mycobacteriosis on the metabolism of wild-caught adult striped bass from Chesapeake Bay using respirometry. Because the spleen is the primary target organ of mycobacteriosis in striped bass, we hypothesized that the disease interferes with the ability of fish to increase their hemato crit in the face of increasing oxygen demands. …

Riverine Macrosystems Ecology: Sensitivity, Resistance, And Resilience Of Whole River Basins With Human Alterations, Kevin E. Mccluney, N Leroy Poff, Margaret A. Palmer, James H. Thorp, Geoffrey C. Poole, Bradley S. Williams, Michael R. Williams, Jill S. Baron

Biological Sciences Faculty Publications

Riverine macrosystems are described here as watershed-scale networks of connected and interacting riverine and upland habitat patches. Such systems are driven by variable responses of nutrients and organisms to a suite of global and regional factors (eg climate, human social systems) interacting with finer-scale variations in geology, topography, and human modifications. We hypothesize that spatial heterogeneity, connectivity, and asynchrony among these patches regulate ecological dynamics of whole networks, altering system sensitivity, resistance, and resilience. Long-distance connections between patches may be particularly important in riverine macrosystems, shaping fundamental system properties. Furthermore, the type, extent, intensity, and spatial configuration of human activities …

Role Of Peripheral Immune Response In Microglia Activation And Regulation Of Brain Chemokine And Proinflammatory Cytokine Responses Induced During Vsv Encephalitis, Christina D. Steel, Kimberly Breving, Susan Tavakoli, Woong-Ki Kim, Larry D. Sanford, Richard P. Ciavarra

Biological Sciences Faculty Publications

We report herein that neuroinvasion by vesicular stomatitis virus (VSV) activates microglia and induces a peripheral dendritic cell (DC)-dependent inflammatory response in the central nervous system (CNS). VSV neuroinvasion rapidly induces multiple brain chemokine and proinflammatory cytokine mRNAs that display bimodal kinetics. Peripheral DC ablation or T cell depletion suppresses the second wave of this response demonstrating that infiltrating T cells are primarily responsible for the bimodal characteristics of this response. The robust infiltrate associated with VSV encephalitis likely depends on sustained production of brain CCL19 and CCR7 expression on infiltrating inflammatory cells. © 2013 Elsevier B.V. All rights reserved.

Developmental Link Between Sex And Nutrition; Doublesex Regulates Sex-Specific Mandible Growth Via Juvenile Hormone Signaling In Stag Beetles, Hiroki Gotoh, Hitoshi Miyakawa, Asano Ishikawa, Yuki Ishikawa, Yasuhiro Sugime, Douglas J. Emlen, Laura C. Lavine, Toru Miura

Biological Sciences Faculty Publications

Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutritiondependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its …

Seasonal Patterns Of Microhabitat Selection By A Sub-Tropical Whip Spider, Phrynus Longipes, In The Luquillo Experimental Forest, Puerto Rico, Caroline A. Curtis, Christopher P. Bloch

Biological Sciences Faculty Publications

Phrynus longipes (Pocock 1894) is a top predator among arboreal invertebrates in the Luquillo Mountains of Puerto Rico, but many aspects of its ecology remain poorly understood. We sampled four of the most abundant tree species in the Luquillo Mountains during the dry and wet seasons of 2008 to evaluate microhabitat preferences of this species. In the dry season, P. longipes occurred significantly less frequently on a palm, Prestoea acuminata var. montana (Arecaceae), than the other tree species. Carapace length and the diameter of the tree on which an individual was found were positively correlated, suggesting competition for substrates. Microhabitat …