Biology Commons^™

Defects In Mating Behavior And Tail Morphology Are The Primary Cause Of Sterility In Caenorhabditis Elegans Males At High Temperature, Emily M. Nett, Nicholas B. Sepulveda, Lisa N. Petrella

Biological Sciences Faculty Research and Publications

Reproduction is a fundamental imperative of all forms of life. For all the advantages sexual reproduction confers, it has a deeply conserved flaw: it is temperature sensitive. As temperatures rise, fertility decreases. Across species, male fertility is particularly sensitive to elevated temperature. Previously, we have shown in the model nematode Caenorhabditis elegans that all males are fertile at 20°C, but almost all males have lost fertility at 27°C. Male fertility is dependent on the production of functional sperm, successful mating and transfer of sperm, and successful fertilization post-mating. To determine how male fertility is impacted by elevated temperature, we analyzed …

Transcriptomic Data Support A Nocturnal Bottleneck In The Ancestor Of Gecko Lizards, Brendan J. Pinto, Stuart V. Nielsen, Tony Gamble

Biological Sciences Faculty Research and Publications

Gecko lizards are a species-rich clade of primarily-nocturnal squamate reptiles. In geckos, adaptations to nocturnality have dramatically reshaped the eye. Perhaps the most notable change is the loss of rod cells in the retina and subsequent “transmutation” of cones into a rod-like morphology and physiology. While many studies have noted the absence of some rod-specific genes, such as the visual pigment Rhodopsin (RH1), these studies have focused on just a handful of species that are nested deep in the gecko phylogeny. Thus, it is not clear whether these changes arose through convergence, are homologous and ubiquitous across geckos, or restricted …

Hypoxia-Inducible Gene Domain 1 Proteins In Yeast Mitochondria Protect Against Proton Leak Through Complex Iv, Ngoc H. Hoang, Vera Strogolova, Jaramys J. Mosley, Rosemary A. Stuart, Jonathan Hosler

Biological Sciences Faculty Research and Publications

Hypoxia-inducible gene domain 1 (HIGD1) proteins are small integral membrane proteins, conserved from bacteria to humans, that associate with oxidative phosphorylation supercomplexes. Using yeast as a model organism, we have shown previously that its two HIGD1 proteins, Rcf1 and Rcf2, are required for the generation and maintenance of a normal membrane potential (ΔΨ) across the inner mitochondrial membrane (IMM). We postulated that the lower ΔΨ observed in the absence of the HIGD1 proteins may be due to decreased proton pumping by complex IV (CIV) or enhanced leak of protons across the IMM. Here we measured the ΔΨ generated by complex …

Embryonic Development Of A Parthenogenetic Vertebrate, The Mourning Gecko (Lepidodactylus Lugubris), Aaron H. Griffing, Thomas J. Sanger, Juan D. Daza, Stuart V. Nielsen, Brendan J. Pinto, Edward L. Stanley, Tony Gamble

Biological Sciences Faculty Research and Publications

Background

One goal of evolutionary developmental biology is to understand the role of development in the origin of phenotypic novelty and convergent evolution. Geckos are an ideal system to study this topic, as they are species‐rich and exhibit a suite of diverse morphologies—many of which have independently evolved multiple times within geckos.

Results

We characterized and discretized the embryonic development of Lepidodactylus lugubris—an all‐female, parthenogenetic gecko species. We also used soft‐tissue μCT to characterize the development of the brain and central nervous system, which is difficult to visualize using traditional microscopy techniques. Additionally, we sequenced and assembled a de …

Do Lianas Shape Ant Communities In An Early Successional Tropical Forest?, Benjamin J. Adams, Evan M. Gora, Michiel Van Breugel, Sergio Estrada-Villegas, Stefan A. Schnitzer, Jefferson S. Hall, Stephen P. Yanoviak

Biological Sciences Faculty Research and Publications

Almost half of lowland tropical forests are at various stages of regeneration following deforestation or fragmentation. Changes in tree communities along successional gradients have predictable bottom‐up effects on consumers. Liana (woody vine) assemblages also change with succession, but their effects on animal succession remain unexplored. Here we used a large‐scale liana removal experiment across a forest successional chronosequence (7–31 years) to determine the importance of lianas to ant community structure. We conducted 1,088 surveys of ants foraging on and living in trees using tree trunk baiting and hand‐collecting techniques at 34 paired forest plots, half of which had all lianas …

C. Elegans Synmuv B Proteins Regulate Spatial And Temporal Chromatin Compaction During Development, Meghan Elizabeth Costello, Lisa N. Petrella

Biological Sciences Faculty Research and Publications

Tissue-specific establishment of repressive chromatin through creation of compact chromatin domains during development is necessary to ensure proper gene expression and cell fate. Caenorhabditis elegans synMuv B proteins are important for the soma/germline fate decision and mutants demonstrate ectopic germline gene expression in somatic tissue, especially at high temperature. We show that C. elegans synMuv B proteins regulate developmental chromatin compaction and that the timing of chromatin compaction is temperature sensitive in both wild type and synMuv B mutants. Chromatin compaction in mutants is delayed into developmental time periods when zygotic gene expression is upregulated and demonstrates an anterior-to-posterior pattern. …

Escaping The Evolutionary Trap? Sex Chromosome Turnover In Basilisks And Related Lizards (Corytophanidae: Squamata), Stuart V. Nielsen, Irán Andira Guzmán-Méndez, Tony Gamble, Madison Blumer, Brendan J. Pinto, Lukáš Kratochvíl, Michail Rovatsos

Biological Sciences Faculty Research and Publications

Most pleurodont lizard families (anoles, iguanas and their relatives), with the exception of the basilisks and casquehead lizards (family Corytophanidae), share homologous XX/XY sex chromosomes, syntenic with chicken chromosome 15. Here, we used a suite of methods (i.e. RADseq, RNAseq and qPCR) to identify corytophanid sex chromosomes for the first time. We reveal that all examined corytophanid species have partially degenerated XX/XY sex chromosomes, syntenic with chicken chromosome 17. Transcriptomic analyses showed that the expression of X-linked genes in the corytophanid, Basiliscus vittatus, is not balanced between the sexes, which is rather exceptional under male heterogamety, and unlike the dosage-balanced …

Investigation Of The Mechanisms Governing Carrier Domain Translocation In S. Aureus Pyruvate Carboxylase, Joshua Hakala

Dissertations (1934 -)

A central debate in protein biochemistry focuses on the mechanism by which ligands contribute to conformational changes in proteins. Two primary hypotheses describe this process: the induced-fit hypothesis and the conformational ensembles hypothesis. In contrast to the induced-fit hypothesis, the conformational ensembles hypothesis states that the protein pre-exists in multiple conformational states, with ligand binding shifting the equilibrium towards a preferred conformation. The contribution of ligand binding to large-scale conformational changes is particularly relevant to multi-domain “swinging-arm” enzymes, for which pyruvate carboxylase (PC) serves as a well characterized paradigm system. PC catalyzes the ATP-dependent carboxylation of pyruvate to oxaloacetate. The …

Global Change Effects On Plant Communities Are Magnified By Time And The Number Of Global Change Factors Imposed, Kimberly J. Komatsu, Meghan L. Avolio, Nathan P. Lemoine, Forest Isbell, Emily Grman, Gregory R. Houseman, Sally E. Koerner, David S. Johnson, Kevin R. Wilcox, Juha M. Alatalo, John P. Anderson, Rien Aerts, Sara G. Baer, Andrew H. Baldwin, Jonathan Bates, Carl Beierkuhnlein, R. Travis Belote, John Blair, Juliette M.G. Bloor, Patrick J. Bohlen, Edward W. Bork, Elizabeth H. Boughton, William D. Bowman, Andrea J. Britton, James F. Cahill Jr., Enrique Chaneton, Nona R. Chiariello, Jimin Cheng, Scott L. Collins, J. Hans C. Cornelissen, Guozhen Du, Anu Eskelinen, Jennifer Firn, Bryan Foster, Laura Gough, Katherine Gross, Lauren M. Hallett, Xingguo Han, Harry Harmens, Mark J. Hovenden, Annika Jagerbrand, Anke Jentsch, Christel Kern, Kari Klanderud, Alan K. Knapp, Juergen Kreyling, Wei Li, Yiqi Luo, Rebecca L. Mcculley, Jennie R. Mclaren, J. Patrick Megonigal, John W. Morgan, Vladimir Onipchenko, Steven C. Pennings, Janet S. Prevéy, Jodi N. Price, Peter B. Reich, Clare H. Robinson, F. Leland Russell, Osvaldo E. Sala, Eric W. Seabloom, Melinda D. Smith, Nadejda A. Soudzilovskaia, Lara Souza, Katherine Suding, K. Blake Suttle, Tony Svejcar, David Tilman, Pedro Tognetti, Roy Turkington, Shannon White, Zhuwen Xu, Laura Yahdjian, Qiang Yu, Pengfei Zhang, Yunhai Zhang

Biological Sciences Faculty Research and Publications

Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (y). In contrast, long-term (≥10 y) experiments show increasing community …

The Transcriptome Of The Veiled Chameleon (Chamaeleo Calyptratus): A Resource For Studying The Evolution And Development Of Vertebrates, Brendan John Pinto, Daren C. Card, Todd A. Castoe, Raul E. Diaz Jr., Stuart V. Nielsen, Paul A. Trainor, Tony Gamble

Biological Sciences Faculty Research and Publications

Purpose

The veiled chameleon (Chamaeleo calyptratus) is an emerging model system for studying functional morphology and evolutionary developmental biology (evo‐devo). Chameleons possess body plans that are highly adapted to an arboreal life style, featuring laterally compressed bodies, split hands/ft for grasping, a projectile tongue, turreted independently moving eyes, and a prehensile tail. Despite being one of the most phenotypically divergent clades of tetrapods, genomic resources for chameleons are severely lacking.

Methods

To address this lack of resources, we used RNAseq to generate 288 million raw Illumina sequence reads from four adult tissues (male and female eyes and gonads) …

Semi-Automatic Extraction Of Liana Stems From Terrestrial Lidar Point Clouds Of Tropical Rainforests, Sruthi M. Krishna Moorthy, Yunfei Bao, Kim Calders, Stefan A. Schnitzer, Hans Verbeeck

Biological Sciences Faculty Research and Publications

Lianas are key structural elements of tropical forests having a large impact on the global carbon cycle by reducing tree growth and increasing tree mortality. Despite the reported increasing abundance of lianas across neotropics, very few studies have attempted to quantify the impact of lianas on tree and forest structure. Recent advances in high resolution terrestrial laser scanning (TLS) systems have enabled us to quantify the forest structure, in an unprecedented detail. However, the uptake of TLS technology to study lianas has not kept up with the same pace as it has for trees. The slower technological adoption of TLS …

Modeling The Impact Of Liana Infestation On The Demography And Carbon Cycle Of Tropical Forests, Manfredo Di Porcia E Brugnera, Félicien Meunier, Marcos Longo, Sruthi M. Krishna Moorthy, Hannes De Deurwaerder, Stefan A. Schnitzer, Damien Bonal, Boris Faybishenko, Hans Verbeeck

Biological Sciences Faculty Research and Publications

There is mounting empirical evidence that lianas affect the carbon cycle of tropical forests. However, no single vegetation model takes into account this growth form, although such efforts could greatly improve the predictions of carbon dynamics in tropical forests. In this study, we incorporated a novel mechanistic representation of lianas in a dynamic global vegetation model (the Ecosystem Demography Model). We developed a liana‐specific plant functional type and mechanisms representing liana–tree interactions (such as light competition, liana‐specific allometries, and attachment to host trees) and parameterized them according to a comprehensive literature meta‐analysis. We tested the model for an old‐growth forest …

Evolution Of The Gekkotan Adhesive System: Does Digit Anatomy Point To One Or More Origins?, Anthony P. Russell, Tony Gamble

Biological Sciences Faculty Research and Publications

Recently-developed, molecularly-based phylogenies of geckos have provided the basis for reassessing the number of times adhesive toe-pads have arisen within the Gekkota. At present both a single origin and multiple origin hypotheses prevail, each of which has consequences that relate to explanations about digit form and evolutionary transitions underlying the enormous variation in adhesive toe pad structure among extant, limbed geckos (pygopods lack pertinent features). These competing hypotheses result from mapping the distribution of toe pads onto a phylogenetic framework employing the simple binary expedient of whether such toe pads are present or absent. It is evident, however, that adhesive …

Persistence Of A Geographically-Stable Hybrid Zone In Puerto Rican Dwarf Geckos, Brendan J. Pinto, James Titus-Mcquillan, Juan D. Daza, Tony Gamble

Biological Sciences Faculty Research and Publications

Determining the mechanisms that create and maintain biodiversity is a central question in ecology and evolution. Speciation is the process that creates biodiversity. Speciation is mediated by incompatibilities that lead to reproductive isolation between divergent populations and these incompatibilities can be observed in hybrid zones. Gecko lizards are a speciose clade possessing an impressive diversity of behavioral and morphological traits. In geckos, however, our understanding of the speciation process is negligible. To address this gap, we used genetic sequence data (both mitochondrial and nuclear markers) to revisit a putative hybrid zone between Sphaerodactylus nicholsi and Sphaerodactylus townsendi in Puerto Rico, …

Moving Beyond Noninformative Priors: Why And How To Choose Weakly Informative Priors In Bayesian Analyses, Nathan P. Lemoine

Biological Sciences Faculty Research and Publications

Throughout the last two decades, Bayesian statistical methods have proliferated throughout ecology and evolution. Numerous previous references established both philosophical and computational guidelines for implementing Bayesian methods. However, protocols for incorporating prior information, the defining characteristic of Bayesian philosophy, are nearly nonexistent in the ecological literature. Here, I hope to encourage the use of weakly informative priors in ecology and evolution by providing a ‘consumer's guide’ to weakly informative priors. The first section outlines three reasons why ecologists should abandon noninformative priors: 1) common flat priors are not always noninformative, 2) noninformative priors provide the same result as simpler frequentist …

Duplications In Corneous Beta Protein Genes And The Evolution Of Gecko Adhesion, Tony Gamble

Biological Sciences Faculty Research and Publications

Corneous proteins are an important component of the tetrapod integument. Duplication and diversification of keratins and associated proteins are linked with the origin of most novel integumentary structures like mammalian hair, avian feathers, and scutes covering turtle shells. Accordingly, the loss of integumentary structures often coincides with the loss of genes encoding keratin and associated proteins. For example, many hair keratins in dolphins and whales have become pseudogenes. The adhesive setae of geckos and anoles are composed of both intermediate filament keratins (IF-keratins, formerly known as alpha-keratins) and corneous beta‐proteins (CBPs, formerly known as beta-keratins) and recent whole genome assemblies …

Effects Of Dry‐Season Irrigation On Leaf Physiology And Biomass Allocation In Tropical Lianas And Trees, Chris M. Smith-Martin, Carolina L. Bastos

Biological Sciences Faculty Research and Publications

Lianas are more abundant in seasonal forests than in wetter forests and are thought to perform better than trees when light is abundant and water is limited. We tested the hypothesis that lianas perform better than trees during seasonal drought using a common garden experiment with 12 taxonomically diverse species (six liana and six tree species) in 12 replicated plots. We irrigated six of the plots during the dry season for four years, while the remaining six control plots received only ambient rainfall. In year 5, we measured stem diameters for all individuals and harvested above‐ and belowground biomass for …

Human Genotyping And An Experimental Model Reveal Npr-C As A Possible Contributor To Morbidity In Coarctation Of The Aorta, John F. Ladisa Jr., Aoy Tomita-Mitchell, Karl D. Stamm, Kathleen Bazan, Donna K. Mahnke, Mary A. Goetsch, Brandon Wegter, Jesse W. Gerringer, Kathryn Repp, Oleg Palygin, Adrian P. Zietara, Mary M. Krolikowski, Thomas J. Eddinger, Abdel A. Alli, Michael E. Mitchell

Biological Sciences Faculty Research and Publications

Coarctation of the aorta (CoA) is a common congenital cardiovascular (CV) defect characterized by a stenosis of the descending thoracic aorta. Treatment exists, but many patients develop hypertension (HTN). Identifying the cause of HTN is challenging because of patient variability (e.g., age, follow-up duration, severity) and concurrent CV abnormalities. Our objective was to conduct RNA sequencing of aortic tissue from humans with CoA to identify a candidate gene for mechanistic studies of arterial dysfunction in a rabbit model of CoA devoid of the variability seen with humans. We present the first known evidence of natriuretic peptide receptor C (NPR-C …

The Hydraulic Efficiency–Safety Trade‐Off Differs Between Lianas And Trees, Masha T. Van Der Sande, Lourens Poorter, Stefan A. Schnitzer, Bettina M.J. Engelbrecht, Lars Markesteijn

Biological Sciences Faculty Research and Publications

Hydraulic traits are important for woody plant functioning and distribution. Associations among hydraulic traits, other leaf and stem traits, and species’ performance are relatively well understood for trees, but remain poorly studied for lianas. We evaluated the coordination among hydraulic efficiency (i.e., maximum hydraulic conductivity), hydraulic safety (i.e., cavitation resistance), a suite of eight morphological and physiological traits, and species’ abundances for saplings of 24 liana species and 27 tree species in wet tropical forests in Panama. Trees showed a strong trade‐off between hydraulic efficiency and hydraulic safety, whereas efficiency and safety were decoupled in lianas. Hydraulic efficiency was strongly …

Repression Of Germline Genes In Caenorhabditis Elegans Somatic Tissues By H3k9 Dimethylation Of Their Promoters, Andreas Rechtsteiner, Meghan Elizabeth Costello, Thea A. Egelhofer, Jocob M. Garrigues, Susan Strome, Lisa N. Petrella

Biological Sciences Faculty Research and Publications

Repression of germline-promoting genes in somatic cells is critical for somatic development and function. To study how germline genes are repressed in somatic tissues, we analyzed key histone modifications in three Caenorhabditis elegans synMuv B mutants, lin-15B, lin-35, and lin-37—all of which display ectopic expression of germline genes in the soma. LIN-35 and LIN-37 are members of the conserved DREAM complex. LIN-15B has been proposed to work with the DREAM complex but has not been shown biochemically to be a member of the complex. We found that, in wild-type worms, synMuv B target genes and germline genes …

Lianas Have A Seasonal Growth Advantage Over Co‐Occurring Trees, Stefan A. Schnitzer, Geertje M. F. Van Der Heijden

Biological Sciences Faculty Research and Publications

The seasonal growth advantage hypothesis posits that plant species that grow well during seasonal drought will increase in abundance in forests with increasing seasonality of rainfall both in absolute numbers and also relative to co‐occurring plant species that grow poorly during seasonal drought. That is, seasonal drought will give some plant species a growth advantage that they lack in aseasonal forests, thus allowing them attain higher abundance. For tropical forest plants, the seasonal growth advantage hypothesis may explain the distribution of drought‐adapted species across large‐scale gradients of rainfall and seasonality. We tested the seasonal growth advantage hypothesis with lianas and …

Isolating And Quantifying The Role Of Developmental Noise In Generating Phenotypic Variation, Maria Kiskowski, Tilmann Glimm, Nickolas Moreno, Tony Gamble, Ylenia Chiari

Biological Sciences Faculty Research and Publications

Genotypic variation, environmental variation, and their interaction may produce variation in the developmental process and cause phenotypic differences among individuals. Developmental noise, which arises during development from stochasticity in cellular and molecular processes when genotype and environment are fixed, also contributes to phenotypic variation. While evolutionary biology has long focused on teasing apart the relative contribution of genes and environment to phenotypic variation, our understanding of the role of developmental noise has lagged due to technical difficulties in directly measuring the contribution of developmental noise. The influence of developmental noise is likely underestimated in studies of phenotypic variation due to …

Blue Grama Grass Genotype Affects Palatability And Preference By Semi-Arid Steppe Grasshoppers, Ava M. Hoffman, Holly Perretta, Nathan P. Lemoine, Melinda D. Smith

Biological Sciences Faculty Research and Publications

The semi-arid shortgrass steppe ecosystem of North America is dominated by blue grama grass (Bouteloua gracilis), a species with substantial intraspecific variability, ecological significance, and economic value. Yet no studies have addressed within species differences in blue grama palatability or insect herbivore preference with respect to plant traits. We performed an experimental study to test the palatability and preference of two blue grama genotypes, wild type versus cultivar, by grasshopper herbivores in the Gomphocerinae subfamily. We found strong evidence that cultivar blue grama was more palatable than wild type and that grasshoppers preferred cultivar plants. Although we could …

Considering The Effects Of Temperature × Nutrient Interactions On The Thermal Response Curve Of Carrying Capacity, Nathan P. Lemoine

Biological Sciences Faculty Research and Publications

Climate warming will likely destabilize populations or drive consumers locally extinct. These predictions arise from consumer–resource models incorporating temperature‐dependent parameters, and the accuracy of these predictions hinges on the validity of temperature scalings for each parameter. Among all parameters, carrying capacity (K) is the most ill‐defined and the temperature scaling of this parameter has no empirically verified foundation. Most studies assume that K declines exponentially with warming, but others have assumed a positive or no relationship between K and temperature. Here, I developed a theoretical foundation for a temperature scaling of K based on physiological principles of temperature …

Population Genetic Structure And Species Delimitation Of A Widespread, Neotropical Dwarf Gecko, Brendan J. Pinto, Guarino R. Colli, Timothy E. Higham, Anthony P. Russell, Daniel P. Scantlebury, Laurie J. Vitt, Tony Gamble

Biological Sciences Faculty Research and Publications

Amazonia harbors the greatest biological diversity on Earth. One trend that spans Amazonian taxa is that most taxonomic groups either exhibit broad geographic ranges or small restricted ranges. This is likely because many traits that determine a species range size, such as dispersal ability or body size, are autocorrelated. As such, it is rare to find groups that exhibit both large and small ranges. Once identified, however, these groups provide a powerful system for isolating specific traits that influence species distributions. One group of terrestrial vertebrates, gecko lizards, tends to exhibit small geographic ranges. Despite one exception, this applies to …

Optimizing Tools For The Investigation Of Flagella Protein Trafficking In Chlamydomonas Reinhardtii, Brandon M. Wills

Master's Theses (2009 -)

Cilia and flagella are synonymous organelles that protrude above the cell surface to propel fluid and monitor signals in the environment. These functions are central to human development and health, as well as for numerous organisms to thrive in their natural habitats. Pioneering studies of their fundamental mechanisms heavily rely on the biflagellate green alga, Chlamydomonas. One example is the extensive characterization of bidirectional intraflagellar transport (IFT), a transport system that perpetually delivers flagellar components between the base and the tip of the flagella. Such characterization has resulted in the discovery of numerous evolutionarily conserved genes crucial for flagella growth …

Ecological Succession In Tropical Forests: The Role Of Edaphic Factors, Initial Conditions And Competition, Sergio Estrada Villegas

Dissertations (1934 -)

Succession is a fundamental process in ecology in which ecosystems recover after disturbances. The goal of the study of ecological succession is to understand the mechanisms responsible for changes in species’ density, diversity, and ecosystem processes. Understanding the mechanisms that determine how young tropical forests change during succession is crucial because approximately half of the world’s tropical forests are regenerating after farmland abandonment, and successional forests are now expected to supply the vast majority of ecosystems services that were provided by old growth forests (e.g. carbon sequestration). Edaphic factors, initial conditions, and competition have been proposed to be key drivers …

Synmuv B Proteins Regulate Chromatin Compaction During Development, Meghan Elizabeth Costello

Dissertations (1934 -)

Tissue-specific establishment of repressive chromatin through creation of compact chromatin domains during development is necessary to ensure proper gene expression and cell fate. C. elegans synMuv B proteins are important for the soma/germline fate decision and mutants demonstrate ectopic germline gene expression in somatic tissue, especially at high temperature. To study chromatin compaction during development we visualized chromatin using both nuclear-spot assays and FISH of native synMuv B regulated loci. We showed that C. elegans synMuv B proteins regulate developmental chromatin compaction and that timing of chromatin compaction was temperature sensitive in both wild-type and synMuv B mutants. Chromatin compaction …

The Yeast Mitochondrial Proteins Rcf1 And Rcf2 Support The Enzymology Of The Cytochrome C Oxidase Complex And Generation Of The Proton Motive Force, Vera Strogolova, Ngoc H. Hoang, Jonathan Hosler, Rosemary A. Stuart

Biological Sciences Faculty Research and Publications

The yeast mitochondrial proteins Rcf1 and Rcf2 are associated with a subpopulation of the cytochrome bc₁–cytochrome c oxidase supercomplex and have been proposed to play a role in the assembly and/or modulation of the activity of the cytochrome c oxidase (complex IV, CIV). Yeast mutants deficient in either Rcf1 or Rcf2 proteins can use aerobic respiration–based metabolism for growth, but the absence of both proteins results in a strong growth defect. In this study, using assorted biochemical and biophysical analyses of Rcf1/Rcf2 single and double null-mutant yeast cells and mitochondria, we further explored how Rcf1 and Rcf2 support …

Connectivity Explains Local Ant Community Structure In A Neotropical Forest Canopy: A Large‐Scale Experimental Approach, Benjamin J. Adams, Stefan A. Schnitzer, Stephen P. Yanoviak

Biological Sciences Faculty Research and Publications

Understanding how habitat structure and resource availability affect local species distributions is a key goal of community ecology. Where habitats occur as a mosaic, variation in connectivity among patches influences both local species richness and composition, and connectivity is a key conservation concern in fragmented landscapes. Similarly, availability of limiting resources frequently determines species coexistence or exclusion. For primarily cursorial arthropods like ants, gaps between neighboring trees are a significant barrier to movement through the forest canopy. Competition for limited resources such as nest sites also promotes antagonistic interactions. Lianas (woody vines) connect normally isolated neighboring tree crowns and often …