Life Sciences Commons^™

Roles Of The Sarcoplasmic/Endoplasmic Reticulum Ca2+-Atpase, Plasma Membrane Ca2+-Atpase And Na+/Ca2+ Exchanger In Regulation Of Heart Rate In Larval Drosophila, Mohati Desai-Shah, A. R. Papoy, M. Ward, Robin L. Cooper

Biology Faculty Publications

We investigated the roles of three regulatory proteins that impact [Ca²⁺]_i within cardiac myocytes of Drosophila melanogaster. The NCX (Na⁺/Ca²⁺ exchanger), PMCA (plasma membrane Ca²⁺-ATPase) and SERCA (sarcoplasmic/endoplasmic reticulum Ca²⁺-ATPase) were compromised by ionic, pharmacological, mutationalmanipulation, and with a combination of approaches, while heart rate (HR) was monitored. A decrease in SERCA function reduced HR more for intact larva in comparison to a dissected larva. Dissected preparations were used to expose the heart directly to agents. A compromised PMCA also reduced HR; however, attenuated NCX function by low [Na^{+ …}

Trapping Mammals In A Cautious World: The Effect Of Disinfectants On Trap Success, James Wilson, K. E. Mabry

Biology Faculty Publications

Disinfecting traps that have captured small mammals is one recommendation for preventing occurrence of hantavirus infection; however, the potential effects of disinfection on small mammal trappability have not been investigated thoroughly. We conducted an experiment to compare the effects of 2 disinfectants (Lysol® and household bleach) on the trappability of 4 small mammal species (Peromyscus maniculatus, Neotamias spp., and Spermophilus lateralis). We established triplicate trap grids in 2 forest types (red fir and mixed conifer), each consisting of a 6 × 6 array of Sherman live-traps placed at 10-m intervals. Traps were given 1 of 3 treatments: control (water), Lysol, …

Tubulin Evolution In Insects: Gene Duplication And Subfunctionalization Provide Specialized Isoforms In A Functionally Constrained Gene Family, Mark G. Nielsen, Sudhindra R. Gadagkar, Lisa Gutzwiller

Biology Faculty Publications

Background: The completion of 19 insect genome sequencing projects spanning six insect orders provides the opportunity to investigate the evolution of important gene families, here tubulins. Tubulins are a family of eukaryotic structural genes that form microtubules, fundamental components of the cytoskeleton that mediate cell division, shape, motility, and intracellular trafficking. Previous in vivo studies in Drosophila find a stringent relationship between tubulin structure and function; small, biochemically similar changes in the major alpha 1 or testis-specific beta 2 tubulin protein render each unable to generate a motile spermtail axoneme. This has evolutionary implications, not a single non-synonymous substitution is …

Seasonal Patterns Of Arthropod Diversity And Abundance On Big Sagebrush, Artemisia Trientata, M P. Stanford, Nancy J. Huntly

Biology Faculty Publications

The sagebrush biotype is the largest in the western United States. This vast sagebrush community is thought to harbor equally vast and diverse arthropod communities, but these remain little explored. Our objective was to examine the diversity, abundance, and seasonal phenology of arthropod taxa found on the dominant shrub of the sagebrush ecosystem, big sagebrush (Artemisia tridentata). We wanted to improve understanding of this little-studied arthropod assemblage that may play significant roles in the dynamics of sagebrush populations and the sagebrush ecosystem. We sampled free-living and gall-forming arthropods from a stratified random sample of sagebrush plants at the Barton Road …

Loss Of Foundation Species Increases Population Growth Of Exotic Forbs In Sagebrush Steppe, J S. Prevey, M J. Germino, Nancy J. Huntly

Biology Faculty Publications

The invasion and spread of exotic plants following land disturbance threatens semiarid ecosystems. In sagebrush steppe, soil water is scarce and is partitioned between deeprooted perennial shrubs and shallower-rooted native forbs and grasses. Disturbances commonly remove shrubs, leaving grass-dominated communities, and may allow for the exploitation of water resources by the many species of invasive, tap-rooted forbs that are increasingly successful in this habitat. We hypothesized that exotic forb populations would benefit from increased soil water made available by removal of sagebrush, a foundation species capable of deep-rooting, in semiarid shrub-steppe ecosystems. To test this hypothesis, we used periodic matrix …

The Combined Influence Of The Local Environment Andregional Enrichment On Bird Species Richness, Ethan P. White, A. H. Hurlbert

Biology Faculty Publications

It is generally accepted that local species richness at a site reflects the combined influence of local and regional processes. However, most empirical studies evaluate the influence of either local environmental variables or regional enrichment but not both simultaneously. Here we demonstrate the importance of combining these processes to understand continental scale richness patterns in breeding birds. We show that neither regional enrichment nor the local environment in isolation is sufficient to characterize observed patterns of species richness. Combining both sets of variables into a single model results in improved model fit and the removal of residual spatial autocorrelation. At …

Complete Plastome Sequences Of Equisetum Arvense And Isoetes Flaccida: Implications For Phylogeny And Plastid Genome Evolution Of Early Land Plant Lineages, K. G. Karol, K. Arumuganthan, J. L. Boore, A. M. Duffy, K. D. E. Everett, J. D. Hall, S. K. Hansen, J. V. Mandoli, D. F. Mandoli, B. D. Mishler, R. G. Olmstead, K. S. Renzaglia, Paul G. Wolf

Biology Faculty Publications

Background Despite considerable progress in our understanding of land plant phylogeny, several nodes in the green tree of life remain poorly resolved. Furthermore, the bulk of currently available data come from only a subset of major land plant clades. Here we examine early land plant evolution using complete plastome sequences including two previously unexamined and phylogenetically critical lineages. To better understand the evolution of land plants and their plastomes, we examined aligned nucleotide sequences, indels, gene and nucleotide composition, inversions, and gene order at the boundaries of the inverted repeats. Results We present the plastome sequences of Equisetum arvense, a …

Chloroplast Genome Sequence Of The Moss Torula Ruralis: Gene Content, Polymorphism, And Structural Arrangement Relative To Other Green Plant Chloroplast Genomes, M. J. Oliver, A. G. Murdock, B. D. Mishler, J. V. Kuehl, J. L. Boore, D. F. Mandoli, K. D. E. Everett, Paul G. Wolf, A. M. Duffy, K. G. Karol

Biology Faculty Publications

Background Tortula ruralis, a widely distributed species in the moss family Pottiaceae, is increasingly used as a model organism for the study of desiccation tolerance and mechanisms of cellular repair. In this paper, we present the chloroplast genome sequence of T. ruralis, only the second published chloroplast genome for a moss, and the first for a vegetatively desiccation-tolerant plant. Results The Tortula chloroplast genome is ~123,500 bp, and differs in a number of ways from that of Physcomitrella patens, the first published moss chloroplast genome. For example, Tortula lacks the ~71 kb inversion found in the large single copy region …

Kinetics Of Hedgehog-Dependent Full-Length Gli3 Accumulation In Primary Cilia And Subsequent Degradation, Xiaohui Wen, Cary Lai, Marie Evangelista, Jo-Anne Hongo, Frederic J. De Sauvage, Suzie J. Scales

Biology Faculty Publications

Hedgehog (Hh) signaling in vertebrates depends on intraflagellar transport (IFT) within primary cilia. The Hh receptor Patched is found in cilia in the absence of Hh and is replaced by the signal transducer Smoothened within an hour of Hh stimulation. By generating antibodies capable of detecting endogenous pathway transcription factors Gli2 and Gli3, we monitored their kinetics of accumulation in cilia upon Hh stimulation. Localization occurs within minutes of Hh addition, making it the fastest reported readout of pathway activity, which permits more precise temporal and spatial localization of Hh signaling events. We show that the species of Gli3 that …

Acoel And Platyhelminth Models For Stem-Cell Research, A. E. Bely, James M. Sikes Ph.D.

Biology Faculty Publications

Acoel and platyhelminth worms are particularly attractive invertebrate models for stem-cell research because their bodies are continually renewed from large pools of somatic stem cells. Several recent studies, including one in BMC Developmental Biology, are beginning to reveal the cellular dynamics and molecular basis of stem-cell function in these animals.

See research article http://www.biomedcentral.com/1471-213X/9/69.

Adult somatic stem cells can play critical roles in postembryonic developmental processes such as tissue renewal, growth, repair, and regeneration [1]. Understanding how such cells are maintained and produce differentiated progeny is thus of general interest in developmental biology, in addition to …

Teaching Species, Mark W. Ellis, Paul G. Wolf

Biology Faculty Publications

A clear understanding of the term "species" is fundamental to the subject of evolution. However, introductory textbooks often fail to address this topic until one of the later chapters, after having used the term species in all preceding chapters. Furthermore, definitions of terms critical to a clear understanding of this subject are often vague or absent in chapters on species concepts. We feel the popular notion of a "species problem" has been unnecessarily inflated by this less-than-effective educational approach. Clearly addressing this essential subject at the beginning of a course on evolution will prepare students to learn the details and …

The Evolution Of Chloroplast Genome Structure In Ferns, Paul G. Wolf, J. M. Roper, A. M. Duffy

Biology Faculty Publications

The plastid genome (plastome) is a rich source of phylogenetic and other comparative data in plants. Most land plants possess a plastome of similar structure. However, in a major group of plants, the ferns, a unique plastome structure has evolved. The gene order in ferns has been explained by a series of genomic inversions relative to the plastome organization of seed plants. Here, we examine for the first time the structure of the plastome across fern phylogeny. We used a PCR-based strategy to map and partially sequence plastomes. We found that a pair of partially overlapping inversions in the region …

Unfurling Fern Biology In The Genomics Age, M. S. Barker, Paul G. Wolf

Biology Faculty Publications

Twenty-first century technology is addressing many of the questions posed by 20th-century biology. Although the new approaches, especially those involving genomic data and bioinformatic tools, were first applied to model organisms, they are now stretching across the tree of life. Here, we review some recent revelations in the ferns. We first examine how DNA sequence data have contributed to our understanding of fern phylogeny. We then address evolution of the fern plastid genome, including reports of high levels of RNA editing. Recent studies are also shedding light on the evolution of fern nuclear genomes. Initial analyses of genomic data suggest …

Snail Grazing Facilitates Growth Of A Bloom-Forming Alga, Michele Guidone, Carol S. Thornber, Emily Field

Biology Faculty Publications

Herbivory often has a negative effect on plants. However, there is a growing number of examples, primarily in terrestrial ecosystems, where herbivory causes an increase in plant size, growth rate, and/or reproductive output. In marine ecosystems, the positive effects of herbivores on macroalgae are not as well studied, although limited evidence exists for herbivore-induced increases in macroalgal growth rates via 2 mechanisms: nutrient addition via grazer defecation, and epiphyte removal. In this study, we examined the effects of grazing by the mud snail Ilyanassa obsoleta on Ulva lactuca, the dominant bloom-forming macroalga in many New England estuaries. We found …

The Ratio Of Gametophytes To Tetrasporophytes Of Intertidal Chondrus Crispus (Gigartinaceae) Across A Salinity Gradient, Michele Guidone, Sean Grace

Biology Faculty Publications

Population studies of the Gigartinaceae (Rhodophyta) have often observed that the ratio of gametophytes to tetrasporophytes varies with the location of the population or the time of sampling. For some species, patterns have emerged that correlate this ratio to one or a few particular environmental variables, such as elevation, wave exposure, or season. Identifying these distributional patterns is an important step towards understanding what (if any) ecological differences exist between the two free-living life history stages.

The purpose of this study was to measure the ratio of gametophytes to tetrasporophytes of intertidal populations of Chondrus crispus across a decreasing salinity …

Reproductive Behavior In Horseshoe Crabs: Does Density Matter?, Jennifer Mattei, Mark Beekey, Adam Rudman, Alyssa Woronik

Biology Faculty Publications

While the four species of horseshoe crabs share many common reproductive traits with respect to their reproductive systems, they do differ with respect to their mating behavior (monogamy vs. polygynandry). Past research has attributed these differences to a number of factors including: spawning densities, operational sex ratios (OSR’s), male condition (or age), environmental and/or genetic factors, or a combination thereof. Mating behaviors in the three Asian horseshoe crab species (Tachypleus gigas , T. tridentatus, and Carcinoscorpius rotundicauda ) with low spawning densities and 1:1 operational sex ratios are typically monogamous. In Limulus polyphemus , mating behavior is more …

Movement Patterns And Population Genetics Of The American Horseshoe Crab In Relation To Long Island Sound Conservation Strategies, Jo-Marie Kasinak, Kirk A. Bartholomew, Mark Beekey, Jennifer Mattei

Biology Faculty Publications

The Connecticut Department of Environmental Protection (CTDEP) established three no-harvest zones for the horseshoe crab (Limulus polyphemus) population as part of a conservation plan for the species. Data from a long-term mark/recapture study of horseshoe crabs in conjunction with a microsatellite-based genetic survey of the population were analyzed to determine if this plan was appropriate to conserve genetic diversity and broaden our knowledge of movement patterns of Limulus in Long Island Sound (LIS). To date, ~53,000 crabs have been tagged over a 10 year period through the Project Limulus program with an annual average recapture rate of 12 …

The Acidic Domains Of The Toc159 Chloroplast Preprotein Receptor Family Are Instrinsically Disordered Protein Domains, Lynn G.L. Richardson, Masoud Jelokhani-Niaraki, Matthew D. Smith

Biology Faculty Publications

Background: The Toc159 family of proteins serve as receptors for chloroplast-destined preproteins. They directly bind to transit peptides, and exhibit preprotein substrate selectivity conferred by an unknown mechanism. The Toc159 receptors each include three domains: C-terminal membrane, central GTPase, and N-terminal acidic (A-) domains. Although the function(s) of the A-domain remains largely unknown, the amino acid sequences are most variable within these domains, suggesting they may contribute to the functional specificity of the receptors.

Results: The physicochemical properties of the A-domains are characteristic of intrinsically disordered proteins (IDPs). Using CD spectroscopy we show that the A-domains of two Arabidopsis Toc159 …

Actions Of Octocoral And Tobacco Cembranoids On Nicotinic Receptors, P. A. Ferchmin, Oné R. Pagán, Henning Ulrich, Ada C. Szeto, Richard M. Hann, Vesna A. Eterović

Biology Faculty Publications

Nicotinic acetylcholine receptors (AChRs) are pentameric proteins that form agonist-gated cation channels through the plasma membrane. AChR agonists and antagonists are potential candidates for the treatment of neurodegenerative diseases. Cembranoids are naturally occurring diterpenoids that contain a 14-carbon ring. These diterpenoids interact with AChRs in complex ways: as irreversible inhibitors at the agonist sites, as noncompetitive inhibitors, or as positive modulators, but no cembranoid was ever shown to have agonistic activity on AChRs. The cembranoid eupalmerin acetate displays positive modulation of agonist-induced currents in the muscle-type AChR and in the related gamma-aminobutyric acid (GABA) type A receptor. Moreover, cembranoids display …

Distribution And Diversity Of Archaeal And Bacterial Ammonia Oxidizers In Salt Marsh Sediments, Nicole S. Moin, Katelyn A. Nelson, Alexander Bush, Anne E. Bernhard

Biology Faculty Publications

Diversity and abundance of ammonia-oxidizing Betaproteobacteria (β-AOB) and archaea (AOA) were investigated in a New England salt marsh at sites dominated by short or tall Spartina alterniflora (SAS and SAT sites, respectively) or Spartina patens (SP site). AOA amoA gene richness was higher than β-AOB amoA richness at SAT and SP, but AOA and β-AOB richness were similar at SAS. β-AOB amoA clone libraries were composed exclusively of Nitrosospira-like amoA genes. AOA amoA genes at SAT and SP were equally distributed between the water column/sediment and soil/sediment clades, while AOA amoA sequences at SAS were primarily affiliated with the …

Methods For Karyotyping And For Localization Of Developmentally Relevant Genes On The Chromosomes Of The Purple Sea Urchin Strongylocentrotus Purpuratus, Celeste C. Eno, Stefanie A. Boettger, Charles W. Walker

Biology Faculty Publications

No abstract provided.

Drosophila Adult Eye Model To Teach Scanning Electron Microscopy In An Undergraduate Cell Biology Laboratory, Meghana Tare, Oorvashi Roy Puli, Sarah M. Oros, Amit Singh

Biology Faculty Publications

We have devised an undergraduate laboratory exercise to study tissue morphology using fruit fly, Drosophila melanogaster, as the model organism. Drosophila can be reared in a cost effective manner in a short period of time. This experiment was a part of the undergraduate curriculum of the cell biology laboratory course aimed to demonstrate the use of scanning electron microscopy (SEM) technique to study the morphology of adult eye of Drosophila. The adult eye of Drosophila is a compound eye, which comprises of 800 unit eyes, and serves as an excellent model for SEM studies. We used flies that …

Proteomic Analysis Of Blastema Formation In Regenerating Axolotl Limbs, Nandini Rao, Deepali Jhamb, Derek J. Milner, Bingbing Li, Fengyu Song, Mu Wang, S. Randal Voss, Mathew Palakal, Michael W. King, Behnaz Saranjami, Holly L.D. Nye, Jo Ann Cameron, David L. Stocum

Biology Faculty Publications

BACKGROUND: Following amputation, urodele salamander limbs reprogram somatic cells to form a blastema that self-organizes into the missing limb parts to restore the structure and function of the limb. To help understand the molecular basis of blastema formation, we used quantitative label-free liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS)-based methods to analyze changes in the proteome that occurred 1, 4 and 7 days post amputation (dpa) through the mid-tibia/fibula of axolotl hind limbs.

RESULTS: We identified 309 unique proteins with significant fold change relative to controls (0 dpa), representing 10 biological process categories: (1) signaling, (2) Ca2+ binding and translocation, (3) transcription, …

Monitoring Heart Function In Larval Drosophila Melanogaster For Physiological Studies, Ann S. Cooper, Kylah E. Rymond, Matthew A. Ward, Easter L. Bocook, Robin L. Cooper

Biology Faculty Publications

We present various methods to record cardiac function in the larval Drosophila. The approaches allow heart rate to be measured in unrestrained and restrained whole larvae For direct control of the environment around the heart another approach utilizes the dissected larvae and removal of the internal organs in order to bathe the heart in desired compounds. The exposed heart also allows membrane potentials to be monitored which can give insight of the ionic currents generated by the myocytes and for electrical conduction along the heart tube. These approaches have various advantages and disadvantages for future experiments that are discussed. …

Historical View And Physiology Demonstration At The Nmj Of The Crayfish Opener Muscle, Ann S. Cooper, Robin L. Cooper

Biology Faculty Publications

Here we present some of the key important discoveries made with the opener neuromuscular (NMJ) preparation of crustaceans and illustrate that there is still much to learn from this model preparation. In understanding the history one can appreciate why even today this NMJ still offers a rich playground to address questions regarding pre- and post-synaptic function and plasticity. The viability and ease of access to the terminal for intracellular as well as extracellular electrophysiology and imaging are significant advantages. The mechanisms behind the modulation of vesicular kinetics and fusion within the high- and low-output terminals are begging for investigation. The …

Phylogeography Of The Frog Leptodactylus Validus (Amphibia: Anura): Patterns And Timing Of Colonization Events In The Lesser Antilles, Arley Camargo, W. Ronald Heyer, Rafael O. De Sá

Biology Faculty Publications

The frog Leptodactylus validus occurs in northern South America, Trinidad and Tobago, and the southern Lesser Antilles (Grenada and St. Vincent). Mitochondrial DNA sequences were used to perform a nested clade phylogeographic analysis (NCPA), to date colonization events, and to analyze colonization patterns using on a relaxed molecular clock and coalescent simulations. L. validus originated on the mainland and first colonized Trinidad with subsequent independent colonizations of Tobago and the Lesser Antilles from Trinidad. The NCPA suggests a historical vicariant event between populations in Trinidad and Tobago from those in the Lesser Antilles. The colonization of Trinidad occurred 1 million …

Measures Of Heart And Ventilatory Rates In Freely Moving Crayfish, Sonya M. Bierbower, Robin L. Cooper

Biology Faculty Publications

The fear, flight or fight response serves as the fundamental physiological basis for examining an organism's awareness of its environment under an impending predator attack. Although it is not known whether invertebrates posses an autonomic nervous system identical to that of vertebrates, evidence shows invertebrates have a sympathetic-like response to regulate the internal environment and ready the organism to act behaviorally to a given stimuli. Furthermore, this physiological response can be feasibly measured and it acts as a biological index for the animal's internal state. Measurements of the physiological response can be directly related to internal and external stressors through …

Scared Sick? Predator-Pathogen Facilitation Enhances The Exploitation Of A Shared Resource, Ricardo A. Ramirez, W E. Snyder

Biology Faculty Publications

Resource use generally increases with greater consumer diversity, an effect often attributed to resource partitioning. Pathogens and predators are two classes of consumer that exhibit differences in ecologically important traits (e.g., size, resource acquisition strategy, foraging location) that could lead to complementary effects on shared prey/hosts. To examine this possibility, we manipulated diversity among a community of predators and pathogens that together attack an herbivorous beetle, Leptinotarsa decemlineata, and measured resulting effects on herbivore suppression and resulting plant damage. We found that herbivore mortality increased, and plant damage decreased, when more natural enemy species were present. However, closer examination revealed …

Time's Arrow Flies Like A Bird: Two Paradoxes For Avian Circadian Biology, Vincent M. Cassone, Jiffin K. Paulose, Melissa G. Whitfield-Rucker, Jennifer L. Peters

Biology Faculty Publications

Biological timekeeping in birds is a fundamental feature of avian physiology, behavior and ecology. The physiological basis for avian circadian rhythmicity has pointed to a multi-oscillator system of mutually coupled pacemakers in the pineal gland, eyes and hypothalamic suprachiasmatic nuclei (SCN). In passerines, the role of the pineal gland and its hormone melatonin is particularly important. More recent molecular biological studies have pointed to a highly conserved mechanism involving rhythmic transcription and translation of "clock genes". However, studies attempting to reconcile the physiological role of pineal melatonin with molecular studies have largely failed. Recent work in our laboratory has suggested …

The Effects Of Fluorescent Tracking Powder On Oxygen Consumption In Salamanders Using Either Cutaneous Or Bimodal Respiration, Sarah A. Orlofske, Kristine L. Grayson, William A. Hopkins

Biology Faculty Publications

Fluorescent powder is gaining attention as an effective method for tracking terrestrial amphibian movements, particularly for species that are too small for conventional tracking equipment. The technique requires coating portions of an animal with fluorescent powder, releasing the animal, and following the trail of powder as it is progressively lost during movement. Recent studies have shown that fluorescent powder has no negative effects on survival or growth. However, a substance that coats the skin, a major respiratory organ in most amphibians, may have sublethal effects on performance and consequently behavior. We tested the effect of fluorescent powder application on the …