Life Sciences Commons^™

Spatiotemporal Variation In Flow-Dependent Recruitment Of Long-Lived Riverine Fish: Model Development And Evaluation, Daisuke Goto, Martin J. Hamel, Jeremy J. Hammen, Mathew L. Rugg, Mark A. Pegg, Valery E. Forbes

School of Biological Sciences: Faculty Publications

Abstract Natural flow regimes can play a major role as an overarching ecosystem driver in reproduction and recruitment of riverine fishes. Human needs for freshwater however have altered hydrology of many riverine systems worldwide, threatening fish population sustainability. To understand and predict how spatiotemporal dynamics of flow regimes influence reproductive and recruitment variability, and ultimately population sustainability of shovelnose sturgeon (Scaphirhynchus platorynchus), we develop a spatially explicit (1D) individual-based population model that mechanistically (via energetics-based processes) simulates daily activities (dispersal, spawning, foraging, growth, and survival). With field observations of sturgeon and habitat conditions in a major tributary of …

Trait-Based Diversification Shifts Reflect Differential Extinction Among Fossil Taxa, Peter J. Wagner, George F. Estabrook

School of Biological Sciences: Faculty Publications

Evolution provides many cases of apparent shifts in diversification associated with particular anatomical traits. Three general models connect these patterns to anatomical evolution: (i) elevated net extinction of taxa bearing particular traits, (ii) elevated net speciation of taxa bearing particular traits, and (iii) elevated evolvability expanding the range of anatomies available to some species. Traitbased diversification shifts predict elevated hierarchical stratigraphic compatibility (i.e., primitive→derived→highly derived sequences) among pairs of anatomical characters. The three specific models further predict (i) early loss of diversity for taxa retaining primitive conditions (elevated net extinction), (ii) increased diversification among …

De Novo Assembly Of The Common Marmoset Transcriptome From Nextgen Mrna Sequences, Mnirnal D. Maudhoo, Dongren Ren, Julien S. Gradnigo, Robert M. Gibbs, Austin C. Lubker, Etsuko N. Moriyama, Jeffrey A. French, Robert B. Norgen Jr.

School of Biological Sciences: Faculty Publications

Background: Nonhuman primates are important for both biomedical studies and understanding human evolution. Although research in these areas has mostly focused on Old World primates, such as the rhesus macaque, the common marmoset (Callithrix jacchus), a New World primate, offers important advantages in comparison to other primates, such as an accelerated lifespan. To conduct Next Generation expression studies or to study primate evolution, a high quality annotation of the marmoset genome is required. The availability of marmoset transcriptome data from five tissues, including both raw sequences and assembled transcripts, will aid in the annotation of the newly released …

The Quarterly Review Of Biology: Population And Community Ecology Of Onto- Genetic Development. Monographs In Population Biology, Volume 51., Chad Brassil

School of Biological Sciences: Faculty Publications

The authors present a derivation, synthesis, and exposition of the consequences of juvenile-adult stage-structured models leading to biomass overcompensation with increasing mortality rates. They compile and elaborate upon their previous work, using the space afforded to provide a thorough explanation and examination of model variants.

They argue the most important stage-structure element to include is, minimally, a model with juveniles and adults. Fundamentally, these elements are linked by maturation of juveniles to adults and the reproduction of adults to produce more juveniles. The major result is that, for the empirically justified set of parameters presented in the book, increasing the …

Solenopsis Invicta Virus (Sinv-1) Infection And Insecticide Interactions In The Red Imported Fire Ant (Hymenoptera: Formicidae), Danielle M. Tufts, Wayne B. Hunter, Blake Bextine

School of Biological Sciences: Faculty Publications

Controlling invasive species is a growing concern; however, pesticides can be detrimental for non-target organisms. The red imported fire ant (Solenopsis invicta Buren; Hymenoptera: Formicidae) has aggressively invaded ~138 million ha in the USA and causes over $6 billion in damage and control efforts annually (Valles 2011). Myriad research studies have been conducted to discover safe biological control agents to manage these invasive pests (Valles et al. 2004; Milks et al. 2008; Oi et al. 2009; Yang et al. 2009; Wang et al. 2010; Callcott et al. 2011; Porter et al. 2011; Tufts et al. 2011). Viruses may be lethal …

Temperature Alters Food Web Body-Size Structure, Jean P. Gibert, John P. Delong

School of Biological Sciences: Faculty Publications

The increased temperature associated with climate change may have important effects on body size and predator– prey interactions. The consequences of these effects for food web structure are unclear because the relationships between temperature and aspects of food web structure such as predator–prey body-size relationships are unknown. Here, we use the largest reported dataset for marine predator–prey interactions to assess how temperature affects predator–prey body-size relationships among different habitats ranging from the tropics to the poles. We found that prey size selection depends on predator body size, temperature and the interaction between the two. Our results indicate that (i) predator–prey …

Response Of Beta Diversity To Pulses Of Ordovician-Silurian Mass Extinction, Simon A.F. Darroch, Peter J. Wagner

School of Biological Sciences: Faculty Publications

Ecologists are increasingly using the fossil record of mass extinction to build predictive models for the ongoing biodiversity crisis. During mass extinctions, major depletions in global (i.e., gamma) diversity may reflect decrease in alpha diversity (i.e., local assemblages support fewer taxa), and/or decrease in beta diversity (such that similar pools of taxa are common to a greater number of local areas). Contrasting the effects of extinction on alpha and beta diversity is therefore central to understanding how global richness becomes depleted over these critical events. Here we investigate the spatial effects of mass extinction by examining changes in alpha, beta, …

Across-Year Social Stability Shapes Network Structure In Wintering Migrant Sparrows, Daizaburo Shizuka, Alexis S. Chaine, Jennifer Anderson, Oscar Johnson, Inger Marie Laursen, Bruce E. Lyon

School of Biological Sciences: Faculty Publications

Migratory birds often form flocks on their wintering grounds, but important details of social structure such as the patterns of association between individuals are virtually unknown. We analysed networks of co-membership in short-term flocks for wintering golden-crowned sparrows (Zonotrichia atricapilla) across three years and discovered social complexity unsuspected for migratory songbirds. The population was consistently clustered into distinct social communities within a relatively small area (~ 7 ha). Birds returned to the same community across years, with mortality and recruitment leading to some degree of turnover in membership. These spatiotemporal patterns were explained by the combination of space …

Mammals Of Kenya’S Protected Areas From 1888 To 2013, Aniko B. Toth, S. Kathleen Lyon, Anna K. Behrensmeyer

School of Biological Sciences: Faculty Publications

Kenya is a world leader in conservation and host to one of the most diverse array of mammals on the planet. As a focus of scientific attention, it is important to be able to assess not only the current state of Kenya’s mammal communities, but also how they have changed over anthropogenic timescales. Comprehensive lists of mammal species from known areas are essential for this goal, and these also provide comparative baselines for assessing changes in mammalian diversity in the future and in the fossil record. Though there is considerable literature available for mammals inhabiting Kenyan protected areas (National Parks …

Early Song Discrimination By Nestling Sparrows In The Wild, Daizaburo Shizuka

School of Biological Sciences: Faculty Publications

Songs play an important role in premating isolation in birds. However, when songs are learned, expe- rience with both conspecific and heterospecific songs in early life could lead to the development of both mixed songs and mixed preferences. One way that such learning errors can be prevented is if birds can discriminate between songs of different species prior to learning and preferentially memorize conspe- cific songs. Prior captive studies have shown that white-crowned sparrows, Zonotrichia leucophrys, are able to discriminate songs early in the process of song memorization, after about 10 days since hatching. I studied early song discrimination in …

A Century Of Change In Kenya’S Mammal Communities: Increased Richness And Decreased Uniqueness In Six Protected Areas, Aniko B. Toth, S. Kathleen Lyons, Anna K. Behrensmeyer

School of Biological Sciences: Faculty Publications

The potential for large-scale biodiversity losses as a result of climate change and human impact presents major challenges for ecology and conservation science. Governments around the world have established national parks and wildlife reserves to help protect biodiversity, but there are few studies on the long-term consequences of this strategy. We use Kenya as a case study to investigate species richness and other attributes of mammal communities in 6 protected areas over the past century. Museum records from African expeditions that comprehensively sampled mammals from these same areas in the early 1900’s provide a baseline for evaluating changes in species …

Variable Facial Plumage In Juvenile Cliff Swallows: A Potential Offspring Recognition Cue?, Allison E. Johnson, Steven Freedberg

School of Biological Sciences: Faculty Publications

Although the ability to recognize related offspring is essential in the evolution of social behavior, the cues that birds use to identify their own offspring are not fully understood. The Cliff Swallow (Petrochelidon pyrrhonota) is a highly social species that nests in large colonies and exhibits a high incidence of both conspecific brood parasitism and extrapair fertilization, behaviors that can potentially lead to parents investing energy and resources in unrelated offspring, which reduces the parents’ genetic fitness. Because parents continue to feed offspring after they leave the nest, parents also risk investing in unrelated offspring by misidentifying their …

Conflicting Selection In The Course Of Adaptive Diversification: The Interplay Between Mutualism And Intraspecific Competition, Rafael L.G. Raimundo, Jean P. Gibert, David H. Hembry, Paulo R. Guimaraes Jr.

School of Biological Sciences: Faculty Publications

Adaptive speciation can occur when a population undergoes assortative mating and disruptive selection caused by frequency-dependent intraspecific competition. However, other interactions, such as mutualisms based on trait matching, may generate conflicting selective pressures that constrain species diversification. We used individual-based simulations to explore how different types of mutualism affect adaptive diversification. A magic trait was assumed to simultaneously mediate mate choice, intraspecific competition, and mutualisms. In scenarios of intimate, specialized mu- tualisms, individuals interact with one or few individual mutualistic partners, and diversification is constrained only if the mutualism is obligate. In other scenarios, increasing numbers of different partners per …

Loss Of Sirt1 Function Improves Intestinal Anti-Bacterial Defense And Protects From Colitis-Induced Colorectal Cancer, Giuseppe Lo Sasso, Dongryeol Ryu, Laurent Mouchiroud, Samodha C. Fernando, Christopher L. Anderson, Elena Katsyuba, Alessandra Piersigilli, Michael O. Hottiger, Kristina Schoonjans, Johan Auwerx

School of Biological Sciences: Faculty Publications

Dysfunction of Paneth and goblet cells in the intestine contributes to inflammatory bowel disease (IBD) and colitisassociated colorectal cancer (CAC). Here, we report a role for the NAD⁺-dependent histone deacetylase SIRT1 in the control of anti-bacterial defense. Mice with an intestinal specific Sirt1 deficiency (Sirt1^int-/-) have more Paneth and goblet cells with a consequent rearrangement of the gut microbiota. From a mechanistic point of view, the effects on mouse intestinal cell maturation are mediated by SIRT1-dependent changes in the acetylation status of SPDEF, a master regulator of Paneth and goblet cells. Our results suggest that targeting …

Different Gene-Specific Mechanisms Determine The ‘Revised-Response’ Memory Transcription Patterns Of A Subset Of A. Thaliana Dehydration Stress Responding Genes, Ning Liu, Yong Ding, Michael Fromm, Zoya Avramova

School of Biological Sciences: Faculty Publications

Plants that have experienced several exposures to

dehydration stress show increased resistance to future

exposures by producing faster and/or stronger

reactions, while many dehydration stress responding

genes in Arabidopsis thaliana super-induce their

transcription as a ‘memory’ from the previous encounter.

A previously unknown, rather unusual,

memory response pattern is displayed by a subset

of the dehydration stress response genes. Despite

robustly responding to a first stress, these genes

return to their initial, pre-stressed, transcript levels

during the watered recovery; surprisingly, they do

not respond further to subsequent stresses of similar

magnitude and duration. This transcriptional behavior

defines the …

Endogenous Aba Extraction And Measurement From Arabidopsis Leaves, Ning Liu, Yong Ding, Michael Fromm, Zoya Avramova

School of Biological Sciences: Faculty Publications

The endogenous messenger, the phytohormone abscisic acid (ABA) plays a major role in plant’s adaption to drought, salinity, cold and other abiotic stresses. In addition to abiotic stress signaling, ABA is involved also in developmental regulation and in responses to diverse biotic stresses. Dehydration stress results in a strong increase in endogenous ABA levels, which can be perceived by RCAR/PYR1/PYL receptors, initiating the ABA signaling pathway to coordinate the genome-wide gene expression, and plants adaptive physiological responses. ABA biosynthesis triggered by environmental cues as well as developmental signals occurs predominantly in vascular parenchyma cells. The measurement of ABA content in …

Dehydration Stress Memory Genes Of Zea Mays; Comparison With Arabidopsis Thaliana, Yong Ding, Laetitia Virlouvet, Ning Liu, Jean-Jack Riethoven, Michael E. Fromm, Zoya Avramova

School of Biological Sciences: Faculty Publications

Background: Pre-exposing plants to diverse abiotic stresses may alter their physiological and transcriptional responses to a subsequent stress, suggesting a form of “stress memory”. Arabidopsis thaliana plants that have experienced multiple exposures to dehydration stress display transcriptional behavior suggesting “memory” from an earlier stress. Genes that respond to a first stress by up-regulating or down-regulating their transcription but in a subsequent stress provide a significantly different response define the ‘memory genes’ category. Genes responding similarly to each stress form the ‘non-memory’ category. It is unknown whether such memory responses exists in other Angiosperm lineages and whether memory is an evolutionarily …

Genome-Wide Gene Expression Effects Of Sex Chromosome Imprinting In Drosophila, Bernardo Lemos, Alan T. Branco, Pan-Pan Jiang, Daniel L. Hartl, Colin D. Meiklejohn

School of Biological Sciences: Faculty Publications

Imprinting is well-documented in both plant and animal species. In Drosophila, the Y chromosome is differently modified when transmitted through the male and female germlines. Here, we report genome-wide gene expression effects resulting from reversed parent-of-origin of the X and Y chromosomes. We found that hundreds of genes are differentially expressed between adult male Drosophila melanogaster that differ in the maternal and paternal origin of the sex chromosomes. Many of the differentially regulated genes are expressed specifically in testis and midgut cells, suggesting that sex chromosome imprinting might globally impact gene expression in these tissues. In contrast, we observed much …

Quorum Sensing Activity And Control Of Yeast-Mycelium Dimorphism In Ophiostoma Floccosum, Alexander Berrocal, Claudia Oviedo, Kenneth W. Nickerson, José Navarrete

School of Biological Sciences: Faculty Publications

Quorum sensing (QS) activity in Ophiostoma fungi has not been described. We have examined the growth conditions on the control of dimorphism in Ophiostoma floccosum, an attractive biocontrol agent against blue-stain fungi, and its relationship with QS activity. In a defined culture medium with l-proline as the N source, a high inoculum size (10⁷ c.f.u. ml^-1) was the principal factor that promoted yeast-like growth. Inoculum size effect can be explained by the secretion of a QS molecule(s) (QSMs) responsible for inducing yeast morphology. QSM candidates were extracted from spent medium and their structure was determined by GC–MS. …

Aba Signaling Is Necessary But Not Sufficient For Rd29b Transcriptional Memory During Successive Dehydration Stresses In Arabidopsis Thaliana, Laetitia Virlouvet, Yong Ding, Hiroaki Fujii, Zoya Avramova, Michael Fromm

School of Biological Sciences: Faculty Publications

Plants subjected to a prior dehydration stress were seen to have altered transcriptional responses during a subsequent dehydration stress for up to 5 days after the initial stress. The abscisic acid (ABA) inducible RD29B gene of Arabidopsis thaliana was strongly induced after the first stress and displayed transcriptional memory with transcript levels nine-fold higher during the second dehydration stress. These increased transcript levels were due to an increased rate of transcription and are associated with an altered chromatin template during the recovery interval between the dehydration stresses. Here we use a combination of promoter deletion/substitutions, mutants in the trans-acting …

Estimating The Frequency Of Cry1f Resistance In Field Populations Of The European Corn Borer (Lepidoptera: Crambidae), Blair D. Siegfried, Murugesan Rangasamy, Haichuan Wang, Terence A. Spencer, Chirakkal V. Haridas, Brigitte Tenhumberg, Douglas V. Sumerford, Nicholas P. Storer

School of Biological Sciences: Faculty Publications

Background: Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) have suppressed European corn borer populations and reduced the pest status of this insect throughout much of the US corn belt. A major assumption of the high-dose/refuge strategy proposed for insect resistance management and Bt corn is that the frequency of resistance alleles is low so that resistant pests surviving exposure to Bt corn will be rare. Results: The frequency of resistance to the Cry1F Bt toxin was estimated using two different screening tools and compared with annual susceptibility monitoring based on diagnostic bioassays and LC_{50 …}

Effect Of The Internet Commerce On Dispersal Modes Of Invasive Alien Species, Magdalena Lenda, Piotr Skorka, Johannes M.H. Knops, Dawid Moron, William J. Sutherland, Karolina Kuszewska, Michal Woyciechowski

School of Biological Sciences: Faculty Publications

The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant …

Effects Of Nitrogen And Phosphorus Fertilization On Soil Carbon Fractions In Alpine Meadows On The Qinghai-Tibetan Plateau, Jin Hua Li, Yu Jie Yang, Bo Wen Li, Wen Jin Li, Gang Wang, Johannes M. H. Knops

School of Biological Sciences: Faculty Publications

In grassland ecosystems, N and P fertilization often increase plant productivity, but there is no concensus if fertilization affects soil C fractions. We tested effects of N, P and N+P fertilization at 5, 10, 15 g m^-2 yr^-1 (N₅, N₁₀, N₁₅, P₅, P₁₀, P₁₅, N₅P₅, N₁₀P₁₀, and N₁₅P₁₅) compared to unfertilized control on soil C, soil microbial biomass and functional diversity at the 0– 20 cm and 20–40 cm depth in an alpine meadow …

Comparison Of The Wing Polyphenic Response Of Pea Aphids (Acyrthosiphon Pisum) To Crowding And Predator Cues, Swapna R. Purandare, Brigitte Tenhumberg, Jennifer A. Brisson

School of Biological Sciences: Faculty Publications

1. Pea aphids (Acyrthosiphon pisum Harris; Hemiptera: Aphididae) exhibit transgenerational wing polyphenism, in which unwinged females produce genetically identical winged offspring in response to environmental cues such as overcrowding and predation risk that indicate poor habitat quality.

2. Laboratory experiments were carried out to explore the intensity of the wing polyphenic response of pea aphids exposed to cues from ladybird predators and crowding, and their response was compared to pea aphids that were not exposed to any cues (control).

3. The study used cues from two different ladybird species: Coccinella septempunctata L. (Coleoptera: Coccinellidae) and Hippodamia convergens Guérin-Méneville (Coleoptera: …

Patterns Of Maximum Body Size Evolution In Cenozoic Land Mammals: Eco-Evolutionary Processes And Abiotic Forcing, Juha J. Saarinen, Alison G. Boyer, James H. Brown, Daniel P. Costa, S.K. Morgan Ernest, Alistair R. Evans, Mikael Fortelius, John L. Gittleman, Marcus J. Hamilton, Larisa E, Harding, Kari Lintulaakso, S. Kathleen Lyons, Jordan G. Okie, Richard M. Sibly, Patrick R. Stephens, Jessica Theodor, Mark D. Uhen, Felisa A. Smith

School of Biological Sciences: Faculty Publications

There is accumulating evidence that macroevolutionary patterns of mammal evolution during the Cenozoic follow similar trajectories on different continents. This would suggest that such patterns are strongly determined by global abiotic factors, such as climate, or by basic eco-evolutionary processes such as filling of niches by specialization. The similarity of pattern would be expected to extend to the history of individual clades. Here, we investigate the temporal distribution of maximum size observed within individual orders globally and on separate continents. While the maximum size of individual orders of large land mammals show differences and comprise several families, the times at …

Effect Of Prey Richness On A Consumer’S Intrinsic Growth Rate, Brian J. Darby, Michael A. Herman

School of Biological Sciences: Faculty Publications

The intrinsic growth rate of nonselective microbivores increases asymptotically with increasing prey biomass, but we do not know how intrinsic growth rate is affected by prey richness. The objective of this experiment was to determine the effect of prey richness on the growth kinetics of nematode predators while grazing on mixed bacterial lawns. We found that the intrinsic growth rate of Caenorhabditis elegans in laboratory culture increased asymptotically with prey richness. The mechanism of this pattern was primarily due to the best available prey species in the mixture: the intrinsic growth rate of the consumer feeding on a mixture of …

De Novo Transcriptome Assembly From Fat Body And Flight Muscles Transcripts To Identify Morph-Specific Gene Expression Profiles In Gryllus Firmus, Neetha Nanoth Vellichirammal, Anthony J. Zera, Rudolf J. Schilder, Cody Wehrkamp, Jean-Jack M. Riethoven, Jennifer A. Brisson

School of Biological Sciences: Faculty Publications

Wing polymorphism is a powerful model for examining many aspects of adaptation. The wing dimorphic cricket species, Gryllus firmus, consists of a long-winged morph with functional flight muscles that is capable of flight, and two flightless morphs. One (obligately) flightless morph emerges as an adult with vestigial wings and vestigial flight muscles. The other (plastic) flightless morph emerges with fully-developed wings but later in adulthood histolyzes its flight muscles. Importantly both flightless morphs have substantially increased reproductive output relative to the flight-capable morph. Much is known about the physiological and biochemical differences between the morphs with respect to adaptations …

Using An Ecosystem Approach To Complement Protection Schemes Based On Organism-Level Endpoints, Clare Bradshaw, Lawrence Kapustka, Lawrence Barenthouse, Justin Brown, Philippe Ciffroy, Valery E. Forbes, Stanislav Geras'kin, Ulrik Kautsky, Francois Brechignac

School of Biological Sciences: Faculty Publications

Radiation protection goals for ecological resources are focused on ecological structures and functions at population-, community-, and ecosystem-levels. The current approach to radiation safety for non-human biota relies on organism-level endpoints, and as such is not aligned with the stated overarching protection goals of international agencies. Exposure to stressors can trigger non-linear changes in ecosystem structure and function that cannot be predicted from effects on individual organisms. From the ecological sciences, we know that important interactive dynamics related to such emergent properties determine the flows of goods and services in ecological systems that human societies rely upon. A previous Task …

Glycosyl Rotation And Distortion By Key Residues In Endocellulase Cel6a From Theromobifida Fusca, Tao Lu, Zuoming Zhang, Chi Zhang

School of Biological Sciences: Faculty Publications

Endocellulases are one kind of the important biodegrading cellulose enzymes. Experimental results show that a rotated and distorted preactivated structure exists before the substrate entering the transition state. The molecular dynamic simulation of endocellulase Cel6A models revealed a correlation between the rotation and distortion of pyranoside ring in −1 glycosyl unit of the substrate. The two key residues, Tyr73 and Ser189, in Cal6A cooperate to rotate and distort the pyranoside ring in the cellulose hydrolysis.

Includes supplementary material.

Eutrophication Weakens Stabilizing Effects Of Diversity In Natural Grasslands, Yann Hautier, Eric W. Seabloom, Elizabeth T. Borer, Peter B. Adler, W. Stanley Harpole, Helmut Hillebrand, Eric M. Lind, Andrew S. Macdougall, Carly J. Stevens, Jonathan D. Bakker, Yvonne M. Buckley, Chengjin Chu, Scott L. Collins, Pedro Daleo, Ellen I. Damschen, Kendi F. Davies, Philip A. Fay, Jennifer Firn, Daniel S. Gruner, Virginia L. Jin, Julia A. Klein, Johannes M. H. Knops, Kimberly J. La Pierre, Wei Li, Rebecca L. Mcculley, Brett A. Melbourne, Joslin L. Moore, Lydia R. O’Halloran, Suzanne M. Prober, Anita C. Risch, Mahesh Sankaran, Martin Schuetz, Andy Hector

School of Biological Sciences: Faculty Publications

Studies of experimental grassland communities^1–7 have demonstrated that plant diversity can stabilize productivity through species asynchrony, in which decreases in the biomass of some species are compensated for by increases in others^1,2. However, it remains unknown whether these findings are relevant to natural ecosystems, especially those for which species diversity is threatened by anthropogenic global change^8–11. Here we analyse diversity–stability relationships from 41 grasslands on five continents and examine how these relationships are affected by chronic fertilization, one of the strongest drivers of species loss globally⁸. Unmanipulated communities with more species had greater …