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University of Nebraska - Lincoln

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2018

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Articles 31 - 54 of 54

Full-Text Articles in Biology

Feeding Immunity: Physiological And Behavioral Responses To Infection And Resource Limitation, Sarah A. Budischak, Christina B. Hansen, Quentin Caudron, Romain Garnier, Tyler R. Kartzinel, István Pelczer, Clayton E. Cressler, Anieke Van Leeuwen, Andrea L. Graham Jan 2018

Feeding Immunity: Physiological And Behavioral Responses To Infection And Resource Limitation, Sarah A. Budischak, Christina B. Hansen, Quentin Caudron, Romain Garnier, Tyler R. Kartzinel, István Pelczer, Clayton E. Cressler, Anieke Van Leeuwen, Andrea L. Graham

School of Biological Sciences: Faculty Publications

Resources are a core currency of species interactions and ecology in general (e.g., think of food webs or competition). Within parasite-infected hosts, resources are divided among the competing demands of host immunity and growth as well as parasite reproduction and growth. Effects of resources on immune responses are increasingly understood at the cellular level (e.g., metabolic predictors of effector function), but there has been limited consideration of how these effects scale up to affect individual energetic regimes (e.g., allocation trade-offs), susceptibility to infection, and feeding behavior (e.g., responses to local resource quality and quantity). We experimentally rewilded laboratory mice (strain …


The Development And Application Of Bioinformatics Core Competencies To Improve Bioinformatics Training And Education, Nicola Mulder, Russell Schwartz, Michelle D. Brazas, Cath Brooksbank, Bruno Gaeta, Sarah L. Morgan, Mark A. Pauley, Anne Rosenwald, Gabriella Rustici, Michael Sierk, Tandy Warnow, Lonnie Welch Jan 2018

The Development And Application Of Bioinformatics Core Competencies To Improve Bioinformatics Training And Education, Nicola Mulder, Russell Schwartz, Michelle D. Brazas, Cath Brooksbank, Bruno Gaeta, Sarah L. Morgan, Mark A. Pauley, Anne Rosenwald, Gabriella Rustici, Michael Sierk, Tandy Warnow, Lonnie Welch

School of Biological Sciences: Faculty Publications

Bioinformatics is recognized as part of the essential knowledge base of numerous career paths in biomedical research and healthcare. However, there is little agreement in the field over what that knowledge entails or how best to provide it. These disagreements are compounded by the wide range of populations in need of bioinformatics training, with divergent prior backgrounds and intended application areas. The Curriculum Task Force of the International Society of Computational Biology (ISCB) Education Committee has sought to provide a framework for training needs and curricula in terms of a set of bioinformatics core competencies that cut across many user …


Evidence For Trait-Based Dominance In Occupancy Among Fossil Taxa And The Decoupling Of Macroecological And Macroevolutionary Success, Peter Wagner, Roy E. Plotnick, S. Kathleen Lyons Jan 2018

Evidence For Trait-Based Dominance In Occupancy Among Fossil Taxa And The Decoupling Of Macroecological And Macroevolutionary Success, Peter Wagner, Roy E. Plotnick, S. Kathleen Lyons

School of Biological Sciences: Faculty Publications

Biological systems provide examples of differential success among taxa, from ecosystems with a few dominant species (ecological success) to clades that possess far more species than sister clades (macroevolutionary success). Macroecological success, the occupation by a species or clade of an unusually high number of areas, has received less attention. If macroecological success reflects heritable traits, then successful species should be related. Genera composed of species possessing those traits should occupy more areas than genera with comparable species richness that lack such traits. Alternatively, if macroecological success reflects autapomorphic traits, then generic occupancy should be a by-product of species richness …


Energy Demand And The Context-Dependent Effects Of Genetic Interactions Underlying Metabolism, Luke A. Hoekstra, Cole R. Julick, Katelyn M. Mika, Kristi L. Montooth Jan 2018

Energy Demand And The Context-Dependent Effects Of Genetic Interactions Underlying Metabolism, Luke A. Hoekstra, Cole R. Julick, Katelyn M. Mika, Kristi L. Montooth

School of Biological Sciences: Faculty Publications

Genetic effects are often context dependent, with the same genotype differentially affecting phenotypes across environments, life stages, and sexes.We used an environmental manipulation designed to increase energy demand during development to investigate energy demand as a general physiological explanation for context-dependent effects of mutations, particularly for those mutations that affect metabolism. We found that increasing the photoperiod during which Drosophila larvae are active during development phenocopies a temperature-dependent developmental delay in a mitochondrial-nuclear genotype with disrupted metabolism. This result indicates that the context-dependent fitness effects of this genotype are not specific to the effects of temperature and may generally result …


Convergent Body Size Evolution Of Crocodyliformes Upon Entering The Aquatic Realm, William Gearty, Jonathan Payne Jan 2018

Convergent Body Size Evolution Of Crocodyliformes Upon Entering The Aquatic Realm, William Gearty, Jonathan Payne

School of Biological Sciences: Posters and Presentations

Twenty-four species of crocodile populate the globe today, but this richness represents a minute fraction of the diversity and disparity of Crocodyliformes since their origin early in the Triassic. Across this clade, three major diversification events into the aquatic realm have occurred. Aquatic and terrestrial habitats impose differing selective pressures on body size. However, previous research on this topic in Crocodyliformes remains qualitative in nature. In this study, our goal was to quantify the influence of habitat (terrestrial versus aquatic) on the evolution of body size in Crocodyliformes. We find a history of repeated body size increase and convergence following …


A Rapid And Efficient Method For Enriching Mitochondrial Dna From Plants, Mackenzie M. Strehle, Emma Purfeerst, Alan C. Christensen Jan 2018

A Rapid And Efficient Method For Enriching Mitochondrial Dna From Plants, Mackenzie M. Strehle, Emma Purfeerst, Alan C. Christensen

School of Biological Sciences: Faculty Publications

Current mitochondrial purification techniques are tedious and protracted due to their emphasis on recovering physiologically active mitochondria. However, for studies that are exclusively interested in isolating mitochondrial DNA (mtDNA) for applications such as PCR and sequencing, respiring mitochondria - and the complex procedures that stem from the need to retain their function - are unnecessary. Still, global DNA extraction methods have proven insufficient for mitochondrial DNA isolation because nuclear mitochondrial DNA segments (NUMTs) pose unique challenges to accurate mtDNA quantification and characterization. We present a rapid and simple extraction technique that maximizes recovery of mitochondrial DNA from plant cells, while …


Gene Turnover And Diversification Of The Α- And Β- Globin Gene Families In Sauropsid Vertebrates, Federico G. Hoffmann, Michael W. Vandewege, Jay F. Storz, Juan C. Opazo Jan 2018

Gene Turnover And Diversification Of The Α- And Β- Globin Gene Families In Sauropsid Vertebrates, Federico G. Hoffmann, Michael W. Vandewege, Jay F. Storz, Juan C. Opazo

School of Biological Sciences: Faculty Publications

The genes that encode the α- and β-chain subunits of vertebrate hemoglobin have served as a model system for elucidating general principles of gene family evolution, but little is known about patterns of evolution in amniotes other than mammals and birds. Here,we report a comparative genomic analysis of the α- and β-globin gene clusters in sauropsids (archosaurs and nonavian reptiles). The objectives were to characterize changes in the size and membership composition of the α- and β-globin gene families within and among the major sauropsid lineages, to reconstruct the evolutionary history of the sauropsid α- and β-globin genes, to resolve …


Molecular Basis Of Hemoglobin Adaptation In The High-Flying Bar-Headed Goose, Chandrasekhar Natarajan, Agnieszka Jendroszek, Amit Kumar, Roy E. Weber, Jeremy R. H. Tame, Angela Fago, Jay F. Storz Jan 2018

Molecular Basis Of Hemoglobin Adaptation In The High-Flying Bar-Headed Goose, Chandrasekhar Natarajan, Agnieszka Jendroszek, Amit Kumar, Roy E. Weber, Jeremy R. H. Tame, Angela Fago, Jay F. Storz

School of Biological Sciences: Faculty Publications

During the adaptive evolution of a particular trait, some selectively fixed mutations may be directly causative and others may be purely compensatory. The relative contribution of these two classes of mutation to adaptive phenotypic evolution depends on the form and prevalence of mutational pleiotropy. To investigate the nature of adaptive substitutions and their pleiotropic effects, we used a protein engineering approach to characterize the molecular basis of hemoglobin (Hb) adaptation in the high-flying bar-headed goose (Anser indicus), a hypoxia-tolerant species renowned for its trans-Himalayan migratory flights. To test the effects of observed substitutions on evolutionarily relevant genetic backgrounds, …


Reproductive Promiscuity In The Variegated Fairy-Wren: An Alternative Reproductive Strategy In The Absence Of Helpers?, Allison E. Johnson, Stephen Pruett-Jones Jan 2018

Reproductive Promiscuity In The Variegated Fairy-Wren: An Alternative Reproductive Strategy In The Absence Of Helpers?, Allison E. Johnson, Stephen Pruett-Jones

School of Biological Sciences: Faculty Publications

Cooperative breeding, in which auxiliary group members help rear related, but nondescendent young, is often explained by kin selection. Reproductive monogamy is predicted in cooperatively breeding systems, as monogamy increases intragroup relatedness and maximizes auxiliary inclusive fitness. While monogamy is observed across many systems, including eusocial insects and cooperatively breeding mammals, some cooperatively breeding birds exhibit high rates of extrapair paternity. Here we quantify paternity and examine the role of auxiliaries on extrapair paternity in the highly cooperative variegated fairy-wren, Malurus lamberti, a species with both male and female auxiliaries. Extrapair paternity occurred in 55.4% of nests, and 39.8% …


Rna-Seq Of Kaposi's Sarcoma Reveals Alterations In Glucose And Lipid Metabolism, For Yue Tso, Andrew V. Kossenkov, Salum J. Lidenge, Owen Ngalamika, John R. Ngowi, Julius Mwaiselage, Jayamanna Wickramasinghe, Eun Hee Kwon, John T. West, Paul M. Lieberman, Charles Wood Jan 2018

Rna-Seq Of Kaposi's Sarcoma Reveals Alterations In Glucose And Lipid Metabolism, For Yue Tso, Andrew V. Kossenkov, Salum J. Lidenge, Owen Ngalamika, John R. Ngowi, Julius Mwaiselage, Jayamanna Wickramasinghe, Eun Hee Kwon, John T. West, Paul M. Lieberman, Charles Wood

School of Biological Sciences: Faculty Publications

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma (KS). It is endemic in a number of sub-Saharan African countries with infection rate of >50%. The high prevalence of HIV-1 coupled with late presentation of advanced cancer staging make KS the leading cancer in the region with poor prognosis and high mortality. Disease markers and cellular functions associated with KS tumorigenesis remain ill-defined. Several studies have attempted to investigate changes of the gene profile with in vitro infection of monoculture models, which are not likely to reflect the cellular complexity of the in vivo lesion environment. Our approach …


Synbiotics For Improved Human Health: Recent Developments, Challenges, And Opportunities, Janina A. Krumbeck, Jens Walter, Robert W. Hutkins Jan 2018

Synbiotics For Improved Human Health: Recent Developments, Challenges, And Opportunities, Janina A. Krumbeck, Jens Walter, Robert W. Hutkins

School of Biological Sciences: Faculty Publications

Research on combining pro- and prebiotics as synbiotics to enhance human and animal health has accelerated in the past 10 years, including many clinical trials that have assessed a diverse range of synbiotic formulations. In this review, we summarize these studies as well as the commercial applications of synbiotics that are available. In particular, we critically assess the claimed health benefits of synbiotic applications and the ecological and therapeutic factors to consider when designing synbiotics and discuss the implications of these concepts for future research in this field.


Presence Of Fruits Decreases Probability Of Retaining Flowers In A Sequentially Flowering Plant, Shivani Jadeja, Brigitte Tenhumberg Jan 2018

Presence Of Fruits Decreases Probability Of Retaining Flowers In A Sequentially Flowering Plant, Shivani Jadeja, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Both intrinsic and extrinsic plant processes affect the fate of flowers along an inflorescence in sequentially flowering plants. We investigated whether the intrinsic process of competition for limited resource between fruits and flowers owing to resource preemption or sink strength of basal fruits, or architectural effects due to posi- tional differences in the probability of retaining flowers, explains a lower probability of retaining distal flowers inYucca glauca. Further, we investigated how the extrinsic process of seed herbivory interacts with the plant’s intrinsic processes of flower retention. We carried out a field experiment to compare flower retention among nine combi- nations …


Student, Instructor, And Observer Agreement Regarding Frequencies Of Scientific Teaching Practices Using The Measurement Instrument For Scientific Teaching-Observable (Misto), Mary F. Durham, Jennifer Knight, Emily K. Bremers, Jameson D. Defreece, Alex R. Paine, Brian A. Couch Jan 2018

Student, Instructor, And Observer Agreement Regarding Frequencies Of Scientific Teaching Practices Using The Measurement Instrument For Scientific Teaching-Observable (Misto), Mary F. Durham, Jennifer Knight, Emily K. Bremers, Jameson D. Defreece, Alex R. Paine, Brian A. Couch

School of Biological Sciences: Faculty Publications

Background: The Scientific Teaching (ST) pedagogical framework encompasses many of the best practices recommended in the literature and highlighted in national reports. Understanding the growth and impact of ST requires instruments to accurately measure the extent to which practitioners implement ST in their courses. Researchers have typically relied on students, instructors, or observers to document course teaching practices, but it remains unclear whether and how these perspectives differ from each other. To address this issue, we modified our previously published instrument to generate the Measurement Instrument for Scientific Teaching-Observable (MISTO), which can be completed by students, instructors, and observers, and …


Influenza D Virus M2 Protein Exhibits Ion Channel Activity In Xenopus Laevis Oocytes, Evan Kesinger, Jianing Liu, Aaron Jensen, Catherine P. Chia, Andrew Demers, Hideaki Moriyama Jan 2018

Influenza D Virus M2 Protein Exhibits Ion Channel Activity In Xenopus Laevis Oocytes, Evan Kesinger, Jianing Liu, Aaron Jensen, Catherine P. Chia, Andrew Demers, Hideaki Moriyama

School of Biological Sciences: Faculty Publications

A new type of influenza virus, known as type D, has recently been identified in cattle and pigs. Influenza D virus infection in cattle is typically asymptomatic; however, its infection in swine can result in clinical disease. Swine can also be infected with all other types of influenza viruses, namely A, B, and C. Consequently, swine can serve as a "mixing vessel" for highly pathogenic influenza viruses, including those with zoonotic potential. Currently, the only antiviral drug available targets influenza M2 protein ion channel is not completely effective. Thus, it is necessary to develop an M2 ion channel blocker capable …


Rnai Doxxes Segregation Distorters On The X, Justin P. Blumenstiel, Colin D. Meiklejohn Jan 2018

Rnai Doxxes Segregation Distorters On The X, Justin P. Blumenstiel, Colin D. Meiklejohn

School of Biological Sciences: Faculty Publications

Species with chromosomal sex determination are susceptible to an evolutionary tug-of-war over sex chromosome segregation. RNA silencing has been proposed to play a role in this intragenomic conflict. Reporting in Developmental Cell, Lin et al. (2018) demonstrate that RNA interference is key to this conflict as a genome defender. ... This work from Lin et al. (2018) provides exciting new evidence that RNA silencing may play a special role as a genome defense against native genes gone rogue. It will be interesting to see how these evolutionary games mediated by RNA silencing influence germline evolution and the dynamics of speciation.


What Types Of Instructional Shifts Do Students Experience? Investigating Active Learning In Science, Technology, Engineering, And Math Classes Across Key Transition Points From Middle School To The University Level, Kenneth Akiha, Emilie Brigham, Brain A. Couch, Justin Lewin, Marilyne Stains, Mackenzie R. Stetzer, Erin L. Vinson, Michelle K. Smith Jan 2018

What Types Of Instructional Shifts Do Students Experience? Investigating Active Learning In Science, Technology, Engineering, And Math Classes Across Key Transition Points From Middle School To The University Level, Kenneth Akiha, Emilie Brigham, Brain A. Couch, Justin Lewin, Marilyne Stains, Mackenzie R. Stetzer, Erin L. Vinson, Michelle K. Smith

School of Biological Sciences: Faculty Publications

Despite the need for a strong Science, Technology, Engineering, and Math (STEM) workforce, there is a high attrition rate for students who intend to complete undergraduate majors in these disciplines. Students who leave STEM degree programs often cite uninspiring instruction in introductory courses, including traditional lecturing, as a reason. While undergraduate courses play a critical role in STEM retention, little is understood about the instructional transitions students encounter upon moving from secondary to post-secondary STEM courses. This study compares classroom observation data collected using the Classroom Observation Protocol for Undergraduate STEM from over 450 middle school, high school, introductory-level university, …


Evolutionary Origins Of Vocal Mimicry In Songbirds, Maria Goller, Daizaburo Shizuka Jan 2018

Evolutionary Origins Of Vocal Mimicry In Songbirds, Maria Goller, Daizaburo Shizuka

School of Biological Sciences: Faculty Publications

Vocal learning is an important behavior in oscines (songbirds). Some songbird species learn heterospecific sounds as well as conspecific vocalizations. The emergence of vocal mimicry is necessarily tied to the evolution of vocal learning, as mimicry requires the ability to acquire sounds through learning. As such, tracking the evolutionary origins of vocal mimicry may provide insights into the causes of variation in song learning programs among songbirds. We compiled a database of known vocal mimics that comprised 339 species from 43 families. We then traced the evolutionary history of vocal mimicry across the avian phylogeny using ancestral trait reconstruction on …


Time-Lagged Effects Of Weather On Plant Demography: Drought And Astragalus Scaphoides, Brigitte Tenhumberg, Elizabeth E. Crone, Satu Ramula, Andrew J. Tyre Jan 2018

Time-Lagged Effects Of Weather On Plant Demography: Drought And Astragalus Scaphoides, Brigitte Tenhumberg, Elizabeth E. Crone, Satu Ramula, Andrew J. Tyre

School of Biological Sciences: Faculty Publications

Temperature and precipitation determine the conditions where plant species can occur. Despite their significance, to date, surprisingly few demographic field studies have considered the effects of abiotic drivers. This is problematic because anticipating the effect of global climate change on plant population viability requires understanding how weather variables affect population dynamics. One possible reason for omitting the effect of weather variables in demographic studies is the difficulty in detecting tight associations between vital rates and environmental drivers. In this paper, we applied Functional Linear Models (FLMs) to long-term demographic data of the perennial wildflower, Astragalus scaphoides, and explored sensitivity of …


Change In Dominance Determines Herbivore Effects On Plant Biodiversity, Sally E. Koerner, Johannes Knops, Dustin J. Strong, 80 More Co-Authors Jan 2018

Change In Dominance Determines Herbivore Effects On Plant Biodiversity, Sally E. Koerner, Johannes Knops, Dustin J. Strong, 80 More Co-Authors

School of Biological Sciences: Faculty Publications

Herbivores alter plant biodiversity (species richness) in many of the world's ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis—that herbivore-induced changes in the competitive environment determine the response of plant biodiversity …


Cd32 Is Expressed On Cells With Transcriptionally Active Hiv But Does Not Enrich For Hiv Dna In Resting T Cells, Mohamed Abdel-Mohsen, Leticia Kuri-Cervantes, Judith Grau-Exposito, Adam M. Spivak, Racheal A. Nell, Costin Tomescu, Surya Kumari Vadrevu, Leila B. Giron, Carla Serra-Peinado, Meritxell Genesca, Josep Castellvi, Guoxin Wu, Perla M. Del Rio Estrada, Mauricio Gonzalez-Navarro, Kenneth Lynn, Collin T. King, Sai Vemula, Kara Cox, Yanmin Wan, Qingsheng Li, Karam Mounzer, Jay Kostman, Ian Frank, Mirko Paiardini, Daria Hazuda, Gustavo Reyes-Teran, Douglas Richman, Bonnie Howell, Pablo Tebas, Javier Martinez-Picado, Vicente Planelles, Maria J. Buzon, Michael R. Betts, Luis J. Montaner Jan 2018

Cd32 Is Expressed On Cells With Transcriptionally Active Hiv But Does Not Enrich For Hiv Dna In Resting T Cells, Mohamed Abdel-Mohsen, Leticia Kuri-Cervantes, Judith Grau-Exposito, Adam M. Spivak, Racheal A. Nell, Costin Tomescu, Surya Kumari Vadrevu, Leila B. Giron, Carla Serra-Peinado, Meritxell Genesca, Josep Castellvi, Guoxin Wu, Perla M. Del Rio Estrada, Mauricio Gonzalez-Navarro, Kenneth Lynn, Collin T. King, Sai Vemula, Kara Cox, Yanmin Wan, Qingsheng Li, Karam Mounzer, Jay Kostman, Ian Frank, Mirko Paiardini, Daria Hazuda, Gustavo Reyes-Teran, Douglas Richman, Bonnie Howell, Pablo Tebas, Javier Martinez-Picado, Vicente Planelles, Maria J. Buzon, Michael R. Betts, Luis J. Montaner

School of Biological Sciences: Faculty Publications

The persistence of HIV reservoirs, including latently infected, resting CD4+ T cells, is the major obstacle to cure HIV infection. CD32a expression was recently reported to mark CD4+ T cells harboring a replication-competent HIV reservoir during antiretroviral therapy (ART) suppression. We aimed to determine whether CD32 expression marks HIV latently or transcriptionally active infected CD4+ T cells. Using peripheral blood and lymphoid tissue of ART-treated HIV+ or SIV+ subjects, we found that most of the circulating memory CD32+ CD4+ T cells expressed markers of activation, including CD69, HLA-DR, CD25, CD38, and Ki67, and …


Temporal Variation In Predation Risk May Explain Daily Rhythms Of Foraging Behavior In An Orb-Weaving Spider, J. Colton Watts, Thomas C. Jones, Ashley Herrig, Madeleine Miller, Brigitte Tenhumberg Jan 2018

Temporal Variation In Predation Risk May Explain Daily Rhythms Of Foraging Behavior In An Orb-Weaving Spider, J. Colton Watts, Thomas C. Jones, Ashley Herrig, Madeleine Miller, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Daily rhythms occur in numerous physiological and behavioral processes across an immense diversity of taxa, but there remain few cases in which mechanistic links between rhythms of trait expression and organismal fitness have been established. We construct a dynamic optimization model to determine whether risk allocation provides an adaptive explanation for the daily foraging rhythm observed in many species using the orb-weaving spider Cyclosa turbinata as a case study. Our model predicts that female C. turbinata should generally start foraging at lower levels of energy reserves (i.e., should be less bold) during midday when predators are most abundant. We also …


Ecoevo-Maps: An Ecology And Evolution Assessment For Introductory Through Advanced Undergraduates, Mindi M. Summers, Brian A. Couch, Jennifer K. Knight, Sara E. Brownell, Alison J. Crowe, Katharine Semsar, Christian D. Wright, Michelle K. Smith Jan 2018

Ecoevo-Maps: An Ecology And Evolution Assessment For Introductory Through Advanced Undergraduates, Mindi M. Summers, Brian A. Couch, Jennifer K. Knight, Sara E. Brownell, Alison J. Crowe, Katharine Semsar, Christian D. Wright, Michelle K. Smith

School of Biological Sciences: Faculty Publications

A new assessment tool, Ecology and Evolution–Measuring Achievement and Progression in Science or EcoEvo-MAPS, measures student thinking in ecology and evolution during an undergraduate course of study. EcoEvo-MAPS targets foundational concepts in ecology and evolution and uses a novel approach that asks students to evaluate a series of predictions, conclusions, or interpretations as likely or unlikely to be true given a specific scenario. We collected evidence of validity and reliability for EcoEvo-MAPS through an iterative process of faculty review, student interviews, and analyses of assessment data from more than 3000 students at 34 associate’s-, bachelor’s-, master’s-, and doctoral-granting institutions. The …


Mitochondrial Dysfunction And Infection Generate Immunity–Fecundity Tradeoffs In Drosophila, Justin L. Buchanan, Colin D. Meiklejohn, Kristi L. Montooth Jan 2018

Mitochondrial Dysfunction And Infection Generate Immunity–Fecundity Tradeoffs In Drosophila, Justin L. Buchanan, Colin D. Meiklejohn, Kristi L. Montooth

School of Biological Sciences: Faculty Publications

Physiological responses to short-term environmental stressors, such as infection, can have long-term consequences for fitness, particularly if the responses are inappropriate or nutrient resources are limited. Genetic variation affecting energy acquisition, storage, and usage can limit cellular energy availability and may influence resourceallocation tradeoffs even when environmental nutrients are plentiful. Here, we utilized Drosophila mitochondrial– nuclear genotypes to test whether disrupted mitochondrial function interferes with nutrient-sensing pathways, and whether this disruption has consequences for tradeoffs between immunity and fecundity. We found that an energetically-compromised genotype was relatively resistant to rapamycin—a drug that targets nutrient-sensing pathways and mimics resource limitation. Dietary …


Binary-State Speciation And Extinction Method Is Conditionally Robust To Realistic Violations Of Its Assumptions, Andrew G. Simpson, Peter J. Wagner, Scott L. Wing, Charles B. Fenster Jan 2018

Binary-State Speciation And Extinction Method Is Conditionally Robust To Realistic Violations Of Its Assumptions, Andrew G. Simpson, Peter J. Wagner, Scott L. Wing, Charles B. Fenster

School of Biological Sciences: Faculty Publications

Phylogenetic comparative methods allow us to test evolutionary hypotheses without the benefit of an extensive fossil record. These methods, however, make simplifying assumptions, among them that clades are always increasing or stable in diversity, an assumption we know to be false. This study simulates hypothetical clades to test whether the Binary State Speciation and Extinction (BiSSE) method can be used to correctly detect relative differences in diversification rate between ancestral and derived character states even as net diversification rates are declining overall. We simulate clades with declining but positive diversification rates, as well those in which speciation rates decline below …