Life Sciences Commons^™

Comparative Riverscape Genomics Of The Rainbow Darter (Etheostoma Caeruleum) In Glaciated And Unglaciated Environments, Jon M. Luiken, Tony Gamble, Peter B. Berendzen

Biological Sciences Faculty Research and Publications

Periodic glaciation during the Quaternary period shaped the contemporary riverscape and distribution of freshwater fishes in the Mississippi River drainage of central North America. The rainbow darter (Etheostoma caeruleum) is a member of this ichthyofauna and has a disjunct distribution in glaciated and unglaciated environments west of the Mississippi River. Based on glacial history of the region, there are different expectations on the observed spatial genetic structure of populations in these environments. The aim of this study was to utilize genome-wide SNP data to compare the population genomic structure of the rainbow darter in river networks with disparate …

Phenology Dictates The Impact Of Climate Change On Geographic Distributions Of Six Co-Occurring North American Grasshoppers, Nathan P. Lemoine

Biological Sciences Faculty Research and Publications

Throughout the last century, climate change has altered the geographic distributions of many species. Insects, in particular, vary in their ability to track changing climates, and it is likely that phenology is an important determinant of how well insects can either expand or shift their geographic distributions in response to climate change. Grasshoppers are an ideal group to test the hypothesis that phenology correlates with range expansion, given that co-occurring confamilial, and even congeneric, species can differ in phenology. Here, I tested the hypothesis that early- and late-season species should possess different range expansion potentials, as estimated by habitat suitability …

Local Canopy Disturbance As An Explanation For Long-Term Increases In Liana Abundance, Stefan A. Schnitzer, David M. Defilippis, Marco Visser, Sergio Estrada-Villegas, Rigoberto Rivera-Camaña, Boris Bernal, Salomé Peréz, Abelino Valdéz, Seberino Valdéz, Antonio Aguilar, James W. Dalling, Eben N. Broadbent, Angelica M. Almeyda Zambrano, Stephen P. Hubbell, Maria Garcia-Leon

Biological Sciences Faculty Research and Publications

Canopy disturbance explains liana abundance and distribution within tropical forests and thus may also explain the widespread pattern of increasing liana abundance; however, this hypothesis remains untested. We used a 10-year study (2007–2017) of 117,100 rooted lianas in an old-growth Panamanian forest to test whether local canopy disturbance explains increasing liana abundance. We found that liana density increased 29.2% and basal area 12.5%. The vast majority of these increases were associated with clonal stem proliferation following canopy disturbance, particularly in liana-dense, low-canopy gaps, which had far greater liana increases than did undisturbed forest. Lianas may be ecological niche constructors, arresting …

The Philosophy Of Outliers: Reintegrating Rare Events Into Biological Science, Chelsea N. Cook, Angela R. Freeman, James C. Liao, Lisa A. Mangiamele

Biological Sciences Faculty Research and Publications

Individual variation in morphology, physiology, and behavior has been a topic of great interest in the biological sciences. While scientists realize the importance of understanding diversity in individual phenotypes, historically the “minority” results (I.e., outlier observations or rare events) of any given experiment have been dismissed from further analysis. We need to reframe how we view “outliers” to improve our understanding of biology. These rare events are often treated as problematic or spurious, when they can be real rare events or individuals driving evolution in a population. It is our perspective that to understand what outliers can tell us in …

Herbivores Alleviate The Negative Effects Of Extreme Drought On Plant Community By Enhancing Dominant Species, Chong Xu, Yuguang Ke, Honghui Wu, Melinda D. Smith, Nathan P. Lemoine, Weiguo Zhang, Qiang Yu

Biological Sciences Faculty Research and Publications

Aims

Both extreme drought and insect herbivores can suppress plant growth in grassland communities. However, most studies have examined extreme drought and insects in isolation, and there is reason to believe that insects might alter the ability of grasslands to withstand drought. Unfortunately, few studies have tested the interactive effects of extreme drought and insect herbivores in grassland communities.

Methods

Here, we tested the drought–herbivore interactions using a manipulative experiment that factorially crossed extreme drought with the exclusion of insect herbivores in a temperate semiarid grassland in Inner Mongolia.

Important Findings

Our results demonstrated that both extreme drought and insect …

Low Temperature Antioxidant Activity Qtl Associate With Genomic Regions Involved In Physiological Cold Stress Tolerance Responses In Rice (Oryza Sativa L.), Huy Phan, Michael Schläppi

Biological Sciences Faculty Research and Publications

Boosting cold stress tolerance in crop plants can minimize stress-mediated yield losses. Asian rice (Oryza sativa L.), one of the most consumed cereal crops, originated from subtropical regions and is generally sensitive to low temperature environments. Within the two subspecies of rice, JAPONICA, and INDICA, the cold tolerance potential of its accessions is highly variable and depends on their genetic background. Yet, cold stress tolerance response mechanisms are complex and not well understood. This study utilized 370 accessions from the Rice Diversity Panel 1 (RDP1) to investigate and correlate four cold stress tolerance response phenotypes: membrane damage, …

Temperature Stressed Caenorhabditis Elegans Males Fail To Mate Successfully And Successful Males Produce Very Few Viable Cross Progeny, Nicholas B. Sepulveda, Lisa N. Petrella

Biological Sciences Faculty Research and Publications

Exposure to moderate temperature stress can have profoundly negative effects on an organism’s reproductive capacity at temperatures where there are minimal or indiscernible effects on the organism as a whole. These negative effects are often more pronounced in males of the species that produce sperm. Previously we showed that few males of Caenorhabditis elegans wild type strains are able to successfully produce any cross progeny after experiencing temperature stress. However, these experiments did not assess the number of progeny from temperature stressed males. To understand if temperature stress can reduce the number of progeny a male sires, we crossed temperature …

The Timing Of Intermittent Hypoxia Differentially Affects Macronutrient Intake And Energy Substrate Utilization In Mice, Sarah N. Framnes-Deboer, Aaron A. Jones, Michelle Y. Kang, Kat Propsom, Lauren R. Nelson, Deanna M. Arble

Biological Sciences Faculty Research and Publications

Sleep apnea is a common sleep disorder characterized by periodic breathing cessation and intermittent hypoxia (IH). Although previous studies have demonstrated that IH alone can influence metabolic outcomes such as body weight, it remains unclear how the timing of IH can specifically affect these outcomes. Here, we examine how pairing 10-h periods of IH to either the animals’ resting phase (e.g., IH during the day) or active phase (e.g., IH during the night) differentially affects body weight, macronutrient selection, energy expenditure, respiratory exchange rate, and glucose tolerance. We find that in contrast to mice exposed to IH during the night, …

Do Male And Female Heterogamety Really Differ In Expression Regulation? Lack Of Global Dosage Balance In Pygopodid Geckos, Michail Rovatsos, Tony Gamble, Stuart V. Nielsen, Arthur Georges, Tariq Ezaz, Lukáš Kratochvíl

Biological Sciences Faculty Research and Publications

Differentiation of sex chromosomes is thought to have evolved with cessation of recombination and subsequent loss of genes from the degenerated partner (Y and W) of sex chromosomes, which in turn leads to imbalance of gene dosage between sexes. Based on work with traditional model species, theory suggests that unequal gene copy numbers lead to the evolution of mechanisms to counter this imbalance. Dosage compensation, or at least achieving dosage balance in expression of sex-linked genes between sexes, has largely been documented in lineages with male heterogamety (XX/XY sex determination), while ZZ/ZW systems are assumed to be usually associated with …

Antibiotic Resistance Patterns Of Escherichia Coli Isolates From The Clinic Through The Wastewater Pathway, Brandon Bojar, Jennifer Sheridan, Rachelle E. Beattie, Caitlin Cahak, Elizabeth Liedhegner, L. Silvia Munoz-Price, Krassimira R. Hristova, Troy Skwor

Biological Sciences Faculty Research and Publications

Antimicrobial resistance (AMR) remains one of the leading global health threats. This study compared antimicrobial resistance patterns among E. coli isolates from clinical uropathogenic Escherichia coli (UPEC) to hospital wastewater populations and throughout an urban wastewater treatment facility – influent, pre- and post-chlorinated effluents. Antibiotic susceptibility of 201 isolates were analyzed against eleven different antibiotics, and the presence of twelve antibiotic resistant genes and type 1 integrase were identified. AMR exhibited the following pattern: UPEC (46.8%) > hospital wastewater (37.8%) > urban post-chlorinated effluent (27.6%) > pre-chlorinated effluent (21.4%) > urban influent wastewater (13.3%). However, multi-drug resistance against three or more antimicrobial classes was …

Effects Of Low-Level Artificial Light At Night On Kentucky Bluegrass And An Introduced Herbivore, Morgan Crump, Cassandra Brown, Robert J. Griffin-Nolan, Lisa Angenoli, Nathan P. Lemoine, Brett M. Seymoure

Biological Sciences Faculty Research and Publications

Increasing evidence suggests that artificial light at night (ALAN) can negatively impact organisms. However, most studies examine the impacts of ALAN on a single species or under high levels of artificial light that are infrequent or unrealistic in urban environments. We currently have little information on how low levels of artificial light emanating from urban skyglow affect plants and their interactions with herbivores. We examined how short-term, low levels of ALAN affect grass and insects, including growth rate, photosynthesis, and stomatal conductance in grass, and foraging behavior and survival in crickets. We compared growth and leaf-level gas exchange of Kentucky …

A Chromosome-Level Genome Assembly Of The Parasitoid Wasp, Cotesia Glomerata (Hymenoptera: Braconidae), Brendan J. Pinto, Jerome J. Weis, Tony Gamble, Paul J. Ode, Ryan Paul, Jennifer M. Zaspel

Biological Sciences Faculty Research and Publications

Hymenopterans make up about 20% of all animal species, but most are poorly known and lack high-quality genomic resources. One group of important, yet understudied hymenopterans are parasitoid wasps in the family Braconidae. Among this understudied group is the genus Cotesia, a clade of ~1,000 species routinely used in studies of physiology, ecology, biological control, and genetics. However, our ability to understand these organisms has been hindered by a lack of genomic resources. We helped bridge this gap by generating a high-quality genome assembly for the parasitoid wasp, Cotesia glomerata (Braconidae; Microgastrinae). We generated this assembly using multiple sequencing …

Sex Chromosome Evolution Among Amniotes: Is The Origin Of Sex Chromosomes Non-Random?, Lukáš Kratochvíl, Tony Gamble, Michail Rovatsos

Biological Sciences Faculty Research and Publications

Sex chromosomes are a great example of a convergent evolution at the genomic level, having evolved dozens of times just within amniotes. An intriguing question is whether this repeated evolution was random, or whether some ancestral syntenic blocks have significantly higher chance to be co-opted for the role of sex chromosomes owing to their gene content related to gonad development. Here, we summarize current knowledge on the evolutionary history of sex determination and sex chromosomes in amniotes and evaluate the hypothesis of non-random emergence of sex chromosomes. The current data on the origin of sex chromosomes in amniotes suggest that …

Heritable Cognitive Phenotypes Influence Appetitive Learning But Not Extinction In Honey Bees, Eda Sezen, Emily Dereszkiewicz, Alvin Hozan, Meghan M. Bennett, Cahit Ozturk, Brian H. Smith, Chelsea N. Cook

Biological Sciences Faculty Research and Publications

Learning and attention allow animals to better navigate complex environments. While foraging, honey bees (Apis mellifera L.) learn several aspects of their foraging environment, such as color and odor of flowers, which likely begins to happen before they evaluate the quality of the food. If bees begin to evaluate quality before they taste food, and then learn the food is depleted, this may create a conflict in what the bee learns and remembers. Individual honey bees differ in their sensitivity to information, thus creating variation in how they learn or do not learn certain environmental stimuli. For example, foraging …

A Brief Review Of Vertebrate Sex Evolution With A Pledge For Integrative Research: Towards ‘Sexomics’, Matthias Stock, Lukáš Kratochvíl, Heiner Kuhl, Michail Rovatsos, Ben J. Evans, Alexander Suh, Nicole Valenzuela, Frederic Veyrunes, Qi Zhou, Tony Gamble, Blanche Capel, Manfred Schartl, Yann Guiguen

Biological Sciences Faculty Research and Publications

Triggers and biological processes controlling male or female gonadal differentiation vary in vertebrates, with sex determination (SD) governed by environmental factors or simple to complex genetic mechanisms that evolved repeatedly and independently in various groups. Here, we review sex evolution across major clades of vertebrates with information on SD, sexual development and reproductive modes. We offer an up-to-date review of divergence times, species diversity, genomic resources, genome size, occurrence and nature of polyploids, SD systems, sex chromosomes, SD genes, dosage compensation and sex-biased gene expression. Advances in sequencing technologies now enable us to study the evolution of SD at broader …

Microbial Find, Inform, And Test Model For Identifying Spatially Distributed Contamination Sources: Framework Foundation And Demonstration Of Ruminant Bacteroides Abundance In River Sediments, Corinne Wiesner-Friedman, Rachelle E. Beattie, Jill R. Stewart, Krassimira R. Hristova, Marc L. Serre

Biological Sciences Faculty Research and Publications

Microbial pollution in rivers poses known ecological and health risks, yet causal and mechanistic linkages to sources remain difficult to establish. Host-associated microbial source tracking (MST) markers help to assess the microbial risks by linking hosts to contamination but do not identify the source locations. Land-use regression (LUR) models have been used to screen the source locations using spatial predictors but could be improved by characterizing transport (i.e., hauling, decay overland, and downstream). We introduce the microbial Find, Inform, and Test (FIT) framework, which expands previous LUR approaches and develops novel spatial predictor models to characterize the transported contributions. We …

Slow-Onset, Potent Inhibition Of Mandelate Racemase By 2-Formylphenylboronic Acid. An Unexpected Adduct Clasps The Catalytic Machinery, Colin D. Douglas, Lia Grandinetti, Nicole M. Easton, Oliver P. Kuehm, Joshua A. Hayden, Meghan C. Hamilton, Martin St. Maurice, Stephen L. Bearne

Biological Sciences Faculty Research and Publications

o-Carbonyl arylboronic acids such as 2-formylphenylboronic acid (2-FPBA) are employed in biocompatible conjugation reactions with the resulting iminoboronate adduct stabilized by an intramolecular N–B interaction. However, few studies have utilized these reagents as active site-directed enzyme inhibitors. We show that 2-FPBA is a potent reversible, slow-onset inhibitor of mandelate racemase (MR), an enzyme that has served as a valuable paradigm for understanding enzyme-catalyzed abstraction of an α-proton from a carbon acid substrate with a high pK_a. Kinetic analysis of the progress curves for the slow onset of inhibition of wild-type MR using a two-step kinetic mechanism …

Photoperiod Manipulation Reveals A Light-Driven Component To Daily Patterns Of Ventilation In Male C57bl/6j Mice, Aaron A. Jones, Lauren R. Nelson, Gabriella M. Marino, Nakia A. Chappelle, Deborah A.M. Joye, Deanna M. Arble

Biological Sciences Faculty Research and Publications

Obstructive sleep apnea is a common sleep disorder that increases risk for cardiovascular disease and mortality. The severity of sleep-disordered breathing in obstructive sleep apnea patients fluctuates with the seasons, opening the possibility that seasonal changes in light duration, or photoperiod, can influence mechanisms of breathing. Photoperiod can have profound effects on internal timekeeping and can reshape metabolic rhythms in mammals. While the daily rhythm in ventilation is largely shaped by the metabolic rate, less is known about whether ventilatory rhythms are altered in accordance with metabolism under different photoperiods. Here, we investigate the relationship between ventilation and metabolism under …

Draft Genome Sequence Of Staphylococcus Succinus Strain Gn1, Isolated From A Basement Floor In Milwaukee, Wi, Grant P. Nickolson, Nasim Maghboli Balasjin, Christopher Marshall

Biological Sciences Faculty Research and Publications

A strain of Staphylococcus succinus was sampled from the floor of the basement of a house and isolated in an undergraduate classroom in Milwaukee, WI. Here, we report the draft genome sequence of this strain.

Lianas Have More Acquisitive Traits Than Trees In A Dry But Not In A Wet Forest, Jose A. Medina-Vega, Frans Bongers, Lourens Poorter, Stefan A. Schnitzer, Frank J. Sterck

Biological Sciences Faculty Research and Publications

1. Lianas are increasing in relative abundance and biomass in many tropical forests. We tested the hypothesis that lianas conform to the fast and acquisitive end of the continuum of plant strategies, allowing lianas to acquire resources faster than trees.
2. We assessed functional traits representative of the leaf (LES) and wood economics spectrum (WES), including plant hydraulics, in 16 liana and 16 tree species in the canopy of two tropical forests at the extremes of the climatic and geological gradient across the Isthmus of Panama.
3. For both forests, we observed a trade-off between the construction of more productive leaves with rapid …

Lianas Do Not Reudce Tree Biomass Accumulation In Young Successional Tripical Dry Forests, Sergio Estrada Villegas, Jefferson S. Hall, Michiel Van Breugel, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

Young successional tropical forests are crucial in the global carbon cycle because they can quickly sequester large quantities of atmospheric carbon. However, lianas (woody vines) can significantly decrease biomass accumulation in young regenerating forests. Lianas are abundant in tropical dry forests, and thus we hypothesized that lianas reduce biomass accretion in dry forests. Lianas may be particularly detrimental to the growth of young trees, which are vulnerable to competition from lianas. Alternatively, lianas may have a stronger negative effect on the largest trees because lianas seek the high-light environment at the top of the forest canopy. We tested these hypotheses …

Unifying Ecosystem Responses To Disturbance Into A Single Statistical Framework, Nathan P. Lemoine

Biological Sciences Faculty Research and Publications

Natural ecosystems are currently experiencing unprecedented rates of anthropogenic disturbance. Given the potential ramifications of more frequent disturbances, it is imperative that we accurately quantify ecosystem responses to severe disturbance. Specifically, ecologists and managers need estimates of resistance and recovery from disturbance that are free of observation error, not biased by temporal stochasticity and that standardize disturbance magnitude among many disparate ecosystems relative to normal interannual variability. Here, I propose a statistical framework that estimates all four components of ecosystem responses to disturbance (resistance, recovery, elasticity and return time), while resolving all of the issues described above. Coupling autoregressive time …

A Graphical Null Model For Scaling Biodiversity–Ecosystem Functioning Relationships, Kathryn E. Barry, Gabriella A. Pinter, Joseph W. Strini, Karrisa Yang, Istvan G. Lauko, Stefan A. Schnitzer, Adam T. Clark, Jane Cowles, Akira S. Mori, Laura Williams, Peter B. Reich, Alexandra J. Wright

Biological Sciences Faculty Research and Publications

1. Global biodiversity is declining at rates faster than at any other point in human history. Experimental manipulations at small spatial scales have demonstrated that communities with fewer species consistently produce less biomass than higher diversity communities. Understanding the consequences of the global extinction crisis for ecosystem functioning requires understanding how local experimental results are likely to change with increasing spatial and temporal scales and from experiments to naturally assembled systems.
2. Scaling across time and space in a changing world requires baseline predictions. Here, we provide a graphical null model for area scaling of biodiversity–ecosystem functioning relationships using observed macroecological patterns: …

Lianas Explore The Forest Canopy More Effectively Than Trees Under Drier Conditions, Jose A. Medina-Vega, Frans Bongers, Stefan A. Schnitzer, Frank J. Sterck

Biological Sciences Faculty Research and Publications

1. Lianas rely on trees for support and access to high-light positions in the forest canopy, but the implications for how lianas explore the canopy compared to trees remain understudied. We present an in situ forest canopy study to test the hypotheses that: (1) lianas favour leaf display over stem investment compared to trees and (2) lianas have greater potential to colonize non-shaded, high-light areas effectively than trees.
2. We compared branches of 16 liana species with those of 16 sympatric tree species in the canopy of two lowland tropical forests with contrasting rainfall regimes in Panama using 40–50 m tall canopy …

Biotic And Abiotic Drivers Of Plant–Pollinator Community Assembly Across Wildfire Gradients, Joseph A. Lamanna, Laura A. Burkle, R. Travis Belote, Jonathan A. Myers

Biological Sciences Faculty Research and Publications

1. Understanding how abiotic disturbance and biotic interactions determine pollinator and flowering-plant diversity is critically important given global climate change and widespread pollinator declines. To predict responses of pollinators and flowering-plant communities to changes in wildfire disturbance, a mechanistic understanding of how these two trophic levels respond to wildfire severity is needed.
2. We compared site-to-site variation in community composition (β-diversity), species richness and abundances of pollinators and flowering plants among landscapes with no recent wildfire (unburned), mixed-severity wildfire and high-severity wildfire in three sites across the Northern Rockies Ecoregion, USA. We used variation partitioning to assess the relative contributions …

Unraveling The Relative Role Of Light And Water Competition Between Lianas And Trees In Tropical Forests: A Vegetation Model Analysis, Félicien Meunier, Hans Verbeeck, Betsy Cowdery, Stefan A. Schnitzer, Chris M. Smith-Martin, Jennifer S. Powers, Xiangtao Xu, Martijn Slot, Hannes P.T. De Deurwaerder, Matteo Detto, Damien Bonal, Marcos Longo, Louis S. Santiago, Michael Dietze

Biological Sciences Faculty Research and Publications

1. Despite their low contribution to forest carbon stocks, lianas (woody vines) play an important role in the carbon dynamics of tropical forests. As structural parasites, they hinder tree survival, growth and fecundity; hence, they negatively impact net ecosystem productivity and long-term carbon sequestration.
2. Competition (for water and light) drives various forest processes and depends on the local abundance of resources over time. However, evaluating the relative role of resource availability on the interactions between lianas and trees from empirical observations is particularly challenging. Previous approaches have used labour-intensive and ecosystem-scale manipulation experiments, which are infeasible in most situations.
3. We propose …

Early Olfactory, But Not Gustatory Processing, Is Affected By The Selection Of Heritable Cognitive Phenotypes In Honey Bee, Meghan M. Bennett, Chelsea N. Cook, Brian H. Smith, Hong Lei

Biological Sciences Faculty Research and Publications

Associative learning enables animals to predict rewards or punishments by their associations with predictive stimuli, while non-associative learning occurs without reinforcement. The latter includes latent inhibition (LI), whereby animals learn to ignore an inconsequential ‘familiar’ stimulus. Individual honey bees display heritable differences in expression of LI. We examined the behavioral and neuronal responses between honey bee genetic lines exhibiting high and low LI. We observed, as in previous studies, that high LI lines learned a familiar odor more slowly than low LI bees. By measuring gustatory responses to sucrose, we determined that perception of sucrose reward was similar between both …

Sperm Fate Is Promoted By The Mir-44 Microrna Family In The Caenorhabditis Elegans Hermaphrodite Germline, Katherine Ann Maniates, Benjamin S. Olson, Allison L. Abbott

Biological Sciences Faculty Research and Publications

Posttranscriptional regulation of gene expression, typically effected by RNA-binding proteins, microRNAs (miRNAs), and translation initiation factors, is essential for normal germ cell function. Numerous miRNAs have been detected in the germline; however, the functions of specific miRNAs remain largely unknown. Functions of miRNAs have been difficult to determine as miRNAs often modestly repress target mRNAs and are suggested to sculpt or fine tune gene expression to allow for the robust expression of cell fates. In Caenorhabditis elegans hermaphrodites, cell fate decisions are made for germline sex determination during larval development when sperm are generated in a short window before the …

Sex Chromosome Turnover In Bent-Toed Geckos (Cyrtodactylus), Shannon E. Keating, Madison Blumer, L. Lee Grismer, Aung Lin, Stuart V. Nielsen, Myint Kyaw Thura, Perry L. Wood Jr., Evan S.H. Quah, Tony Gamble

Biological Sciences Faculty Research and Publications

Lizards and snakes (squamates) are known for their varied sex determining systems, and gecko lizards are especially diverse, having evolved sex chromosomes independently multiple times. While sex chromosomes frequently turnover among gecko genera, intrageneric turnovers are known only from Gekko and Hemidactylus. Here, we used RADseq to identify sex-specific markers in two species of Burmese bent-toed geckos. We uncovered XX/XY sex chromosomes in Cyrtodactylus chaunghanakwaensis and ZZ/ZW sex chromosomes in Cyrtodactylus pharbaungensis. This is the third instance of intrageneric turnover of sex chromosomes in geckos. Additionally, Cyrtodactylus are closely related to another genus with intrageneric turnover, Hemidactylus. …