Biology Commons^™

Tissue-Specific Thyroid Hormone Regulation Of Gene Transcripts Encoding Iodothyronine Deiodinases And Thyroid Hormone Receptors In Striped Parrotfish (Scarus Iseri), Kaitlin M. Johnson, Sean C. Lema

Biological Sciences

In fish as in other vertebrates, the diverse functions of thyroid hormones are mediated at the peripheral tissue level through iodothyronine deiodinase (dio) enzymes and thyroid hormone receptor (tr) proteins. In this study, we examined thyroid hormone regulation of mRNAs encoding the three deiodinases dio1, dio2 and dio3 – as well as three thyroid hormone receptors trαA, trαB and trβ – in initial phase striped parrotfish (Scarus iseri). Parrotfish were treated with dissolved phase T₃ (20 nM) or methimazole (3 mM) for 3 days. Treatment with exogenous T₃ elevated circulating T₃, while the …

A Preliminary Study Of The Vegetation Of Vernal Pools Of Acadia National Park, Maine, U.S.A, Brett Ciccotelli, Tanner B. Harris, Bruce Connery, Nishanta Rajakaruna

Biological Sciences

We conducted a preliminary floristic study of six vernal pools in Acadia National Park on Mount Desert Island, Maine. Plant species were recorded on three sampling dates from April to October, 2008. Sixty-five vascular plant species from 26 families were recorded. Of these, 27 are considered occasional or uncommon in Acadia National Park. Thirteen species are new reports for vernal pools in the northeastern United States. This represents the first published study of the vernal pool flora of Acadia National Park.

Predator-Induced Demographic Shifts In Coral Reef Fish Assemblages, Benjamin I. Ruttenberg, Scott L. Hamilton, Sheila M. Walsh, Mary K. Donovan, Alan Friedlander, Edward Demartini, Enric Sala, Stuart A. Sandin

Biological Sciences

In recent years, it has become apparent that human impacts have altered community structure in coastal and marine ecosystems worldwide. Of these, fishing is one of the most pervasive, and a growing body of work suggests that fishing can have strong effects on the ecology of target species, especially top predators. However, the effects of removing top predators on lower trophic groups of prey fishes are less clear, particularly in highly diverse and trophically complex coral reef ecosystems. We examined patterns of abundance, size structure, and age-based demography through surveys and collection-based studies of five fish species from a variety …

Using Portfolio Theory To Assess Tradeoffs Between Return From Natural Capital And Social Equity Across Space, Benjamin S. Halpern, Crow White, Sarah E. Lester, Christopher Costello, Steven D. Gaines

Biological Sciences

Spatial variance in returns from natural resources, driven by resource dynamics and regulations, can have strong consequences for equitable delivery of value to individuals and communities. Yet resource management models implicitly weight returns equally across space, even when space is explicitly included in model dynamics and policy. Here we translate financial portfolio theory from the temporal to spatial realm and use it to quantify the inherent tradeoff between resource returns and social equity, defined as a more uniform distribution of resource value across space. We illustrate this approach with a marine case study of the Channel Islands, California, USA. Depending …

Distinct Microbiome In Pouchitis Compared To Healthy Pouches In Ulcerative Colitis And Familial Adenomatous Polyposis, Garrett C. Zella, Elizabeth J. Hait, Tiffany Glavan, Dirk Gevers, Doyle V. Ward, Christopher L. Kitts, Joshua R. Korzenik

Biological Sciences

Background: Pouchitis occurs in up to 50% of patients with ulcerative colitis (UC) undergoing ileal pouch anal anastomosis (IPAA). Pouchitis rarely occurs in patients with familial adenomatous polyposis (FAP) who undergo IPAA. Our aim was to compare mucosal and luminal flora in patients with UC-associated pouchitis (UCP), healthy UC pouches (HUC), and healthy FAP pouches (FAP).

Methods: Nineteen patients were enrolled in thi s cross-sectional study (nine UCP, tl1ree HUC, seven FAP). Patie nts with active pouchitis were identified using the Pouchitis Disease Activity Index (PDAI). Ileal pouch mucosal biopsies and fecal samples were analyzed with a 16S rDNA-based terminal …

Homocysteine: A Potential Molecular Link Between Alzheimer's Disease And Type 2 Diabetes Mellitus, Cyndel Carreau

Biological Sciences

In order to elucidate some of the mechanisms through which Alzheimer’s disease (AD) and Type II Diabetes Mellitus (T2DM) are linked, this study investigated the effects of elevated plasma homocysteine levels – a risk factor for AD – in a rat model of T2DM. Both elevated plasma homocysteine levels and T2DM are associated with cognitive deficits and are recognized as strong risk factors for the development of AD. The present experiment examined the effects of diet-induced hyperhomocysteinemia on the development of cognitive impairments and insulin-resistance, as well as on the insulin signaling cascade, in a diet-induced obese rat model of …

Characterization Of Rna Aptamers To Drosophila Splicing Protein B52”, Benjamin Stern

Biological Sciences

The protein B52 is an essential component of the spliceosome in Drosophila M. and is responsible for processing precursor-mRNA. B52 belongs to a family of proteins named SR proteins which are critical in initiation and commitment of RNA splicing. Analogous to human SRp55, B52 has been shown to be responsible for alternative and constitutive splicing during a multitude of cellular and developmental events. RNA aptamers selected during an in vitro selection and amplification process (SELEX) for B52 were found to have a co-variation in the stem of these aptamers. Using biochemical and structural techniques, I will explore the RNA-protein interaction …

The Role Of Rac1 Signaling In Tissue Polarity And Branching Morphogenesis During Salivary Gland Development, Janice Jin

Biological Sciences

Salivary gland development in embryonic mouse occurs through the process of branching morphogenesis and differentiation to ultimately give rise to a fully functional, saliva-secreting adult gland. During branching morphogenesis, epithelial cells establish an apical and basal pole which determines the ultimate direction in which salivary fluid and proteins are secreted. Exactly how salivary tissue polarity is determined on a cellular and glandular level is not fully understood. Rac1, a member of the Rho GTPase family, is an intracellular signal transducer that has been shown in other cell types to regulate cell polarization. Rac1 is also important for the organization of …

The Truth About Models: How Well Do Mechanical Models Mimic The Observed Gender Distributions In Two-Child Families?, William D. Stansfield, Matthew A. Carlton

Biological Sciences

We question the use of mechanical models, such as coin flipping, to represent the probabilities of gender distributions in sibship families consisting of two children. Both the assumptions of the models and the reliability of the data should be evaluated. Using models without these critical evaluations may tend to perpetuate myths rather than elucidate biological realities.

Regional Scale Monitoring Of Methane Production By Dairy Farm Ungulates; A Proposal To The National Science Foundation (Nsf) And The National Ecological Observatory Network (Neon, Inc.), Lindsey Anne Peterson

Biological Sciences

No abstract provided.

The Relationship Between 11-Ketotestosterone, Cortisol, And Testosterone And Condition Index For Poecilia Reticulata, Shelly Gupta, Brandy G. Kalbach

Biological Sciences

The guppy, Poecilia reticulata, is a common study organism for behavioral and other ecological experiments (Houde, 1997).  As far as we know, no previous data have been compiled regarding hormones and condition index of guppies.  In this experiment we examined the relationship between circulating levels of three hormones (testosterone, 11-ketotestosterone and cortisol) and condition index in males and also made comparisons among the hormone levels, for three guppy sites from the northern range of Trinidad – Aripo River, Marianne River and Small Crayfish River.  Hormone samples were obtained using non-invasive water borne techniques and quantified by our collaborator.  The condition …

Exposure To Ultraviolet Radiation Causes Proteomic Changes In Embryos Of The Purple Sea Urchin, Strongylocentrotus Purpuratus, Joseph P. Campanale, Lars Tomanek, Nikki L. Adams

Biological Sciences

We performed experiments to determine how environmentally relevant ultraviolet radiation (UVR) affects protein expression during early development in the sea urchin, Strongylocentrotus purpuratus. To model the protein-mediated cell cycle response to UV-irradiation, six batches of embryos were exposed to UVR, monitored for both delays in the first mitotic division and changes in the proteome at two specific developmental time points. Embryos were exposed to or protected from artificial UVR (11.5 W/m²) for 25 or 60 min. These levels of UVR are within the range we have measured in coastal waters between 0.5 and 2 m. Embryos treated with …

Acquired Traits Revisited, William D. Stansfield

Biological Sciences

Most biology texts villify Lamarck's concept of “inheritance of acquired characters” and leave the impression that all acquired characters are never transmitted to offspring. However, recent research indicates that this is not true! Some “acquired” traits are inherited. I profile some of these striking cases and their importance for evolution and for understanding a broader epigenetic context for heredity and ontogeny (the emerging field of “evo-devo”). Further, I discuss how such cases, even considered as exceptions, contribute to understanding the nature of science, both the role of general rules in biology and the occurrence of conceptual change, or paradigm shifts.

Escape From Competition: Neighbors Reduce Centaurea Stoebe Performance At Home But Not Away, Ragan Callaway, Lauren Waller, Alecu Diaconu, Robert Pal, Alexandra Collins, Heinz Mueller-Schaerer, John Maron

Biological Sciences

The greater abundance of some exotic plants in their nonnative ranges might be explained in part by biogeographic differences in the strength of competition, but these competitive effects have not been experimentally examined in the field. We compared the effects of neighbors on the growth and reproduction of spotted knapweed (Centaurea stoebe) in Europe, where it is native, and in Montana, where it is invasive. There were strong negative competitive effects of neighboring vegetation on C. stoebe growth and reproduction in Europe. In contrast, identical experiments in Montana resulted in insignificant impacts on C. stoebe. Although the mechanisms that produce …

Ecological Strategies In California Chaparral: Interacting Effects Of Soils, Climate, And Fire On Specific Leaf Area, Brian Anacker, Nishanta Rajakaruna, David D. Ackerly, Susan Harrison, Jon Keeley, Michael Vasey

Biological Sciences

Background: High values of specific leaf area (SLA) are generally associated with high maximal growth rates in resource-rich conditions, such as mesic climates and fertile soils. However, fire may complicate this relationship since its frequency varies with both climate and soil fertility, and fire frequency selects for regeneration strategies (resprouting versus seeding) that are not independent of resource-acquisition strategies. Shared ancestry is also expected to affect the distribution of resource-use and regeneration traits.

Aims: We examined climate, soil, and fire as drivers of community-level variation in a key functional trait, SLA, in chaparral in California.

Methods: We quantified the phylogenetic, …

Snp-Based Mapping Of Crossover Recombination In Caenorhabditis Elegans, Grace C. Bazan, Kenneth J. Hillers

Biological Sciences

Caenorhabditis elegans is an important experimental organism for the study of recombination during meiosis. Here, we provide methods for the use of single-nucleotide polymorph isms (SNPs) for the study of crossing over in C. elegans.

The Control Of Marine Biofouling On Xerogel Surfaces With Nanometer-Scale Topography, Nikhil Gunari, Lenora H. Brewer, Stephanie M. Bennett, Anastasiya Sokolova, Nadine D. Kraut, John A. Finlay, Anne E. Meyer, Gilbert C. Walker, Dean E. Wendt, Maureen E. Callow, James A. Callow, Frank V. Bright, Michael R. Detty

Biological Sciences

Mixtures of n-octadecyltrimethoxysilane (C18, 1-5 mole-%), n-octyltriethoxysilane (C8) and tetraethoxysilane (TEOS) gave xerogel surfaces of varying topography. The 1:49:50 C18/C8/TEOS xerogel formed 100-400-nm-wide, 2-7-nm deep pores by AFM while coatings with ≥3% C18 were free of such features. Segregation of the coating into alkane-rich and alkane-deficient regions in the 1:49:50 C18/C8/TEOS xerogel was observed by IR microscopy. Immersion in ASW for 48 h gave no statistical difference in surface energy for the 1:49:50 C18/C8/TEOS xerogel and a significant increase for the 50:50 C8/TEOS xerogel. Settlement of barnacle cyprids and removal of juvenile barnacles, settlement of zoospores of the …

Observed And Modeled Bio-Optical, Bioluminescent, And Physical Properties During A Coastal Upwelling Event In Monterey Bay, California, Igor Shulman, Mark A. Moline, Bradley Penta, Stephanie Anderson, Matthew Oliver, Steven H.D. Haddock

Biological Sciences

During spring and summer time, coastal upwelling influences circulation and ecosystem dynamics of the Monterey Bay, California, which is recognized as a National Marine Sanctuary. Observations of physical, bio‐optical properties (including bioluminescence) together with results from dynamical biochemical and bioluminescence models are used to interpret the development of the upwelling event during August 2003 in Monterey Bay, California. Observations and the biochemical model show the development of a phytoplankton bloom in the southern portion of Monterey Bay. Model results show an increase of nutrients in the southern portion of the bay, where nutrient‐rich water masses are brought in by the …

Physical Habitat And Social Conditions Across A Coral Reef Shape Spatial Patterns Of Intraspecific Behavioral Variation In A Demersal Fish, Meagan N. Schrandt, Kristin M. Hardy, Kaitlin M. Johnson, Sean C. Lema

Biological Sciences

As coral reef ecosystems decline in health worldwide, reef-associated fishes are being impacted by changes to their coral reef habitats. While previous studies have shown coral reef structure to affect the demography of reef fishes, changes in reef conditions may also impact the behavior of reef fishes as they cope with altered habitats. In this study, we examined spatial patterns of intraspecific behavioral variation in the bicolor damselfish (Stegastes partitus) across the fringing reefs of Curaçao (Caribbean Sea), and explored how this behavioral variation associated with physical and social conditions on the reef. Principal components analysis (PCA) condensed …

The Deadly Effects Of ‘‘Nonlethal’’ Predators, Shannon J. Mccauley, Locke Rowe, Marie-Josee Fortin

Biological Sciences

Nonconsumptive predator effects are widespread and include plasticity as well as general stress responses. Caged predators are often used to estimate nonconsumptive effects, and numerous studies have focused on the larval stages of animals with complex life cycles. However, few of these studies test whether nonconsumptive predator effects, including stress responses, are exclusively sublethal. Nor have they assessed whether these effects extend beyond the larval stage, affecting success during stressful life-history transitions such as metamorphosis. We conducted experiments with larvae of a dragonfly (Leucorrhinia intacta) that exhibits predator-induced plasticity to assess whether the mere presence of predators affects …

Lichens Of The Callahan Mine, A Copper- And Zinc-Enriched Superfund Site In Brooksville, Maine, U.S.A., Nishanta Rajakaruna, Tanner B. Harris, Stephen R. Clayden, Alison C. Dibble, Fred C. Olday

Biological Sciences

Metal-enriched habitats often harbor physiologically distinct biotas able to tolerate and accumulate toxic metals. Plants and lichens that accumulate metals have served as effective indicators of ecosystem pollution. Whereas the diversity of metal-tolerant lichens has been well documented globally, the literature of metal-tolerant lichen communities for eastern North America is limited. We examined the lichen flora of the Callahan Mine, a Cu-, Pb-, and Zn-enriched superfund site in Brooksville, Hancock County, Maine, U.S.A. Through collections along transects across metal-contaminated areas of the mine, we documented 76 species of lichens and related fungi. Fifty species were saxicolous, 26 were terricolous. Forty-three …

Environmental Proteomics: Changes In The Proteome Of Marine Organisms In Response To Environmental Stress, Pollutants, Infection, Symbiosis, And Development, Lars Tomanek

Biological Sciences

Environmental proteomics, the study of changes in the abundance of proteins and their post-translational modifications, has become a powerful tool for generating hypotheses regarding how the environment affects the biology of marine organisms. Proteomics discovers hitherto unknown cellulareffects of environmental stressors such as changes in thermal, osmotic, and anaerobic conditions. Proteomic analyses have advanced the characterization of the biological effects of pollutants and identified comprehensive and pollutant-specific sets of biomarkers, especially those highlighting post-translational modifications. Proteomic analyses of infected organisms have highlighted the broader changes occurring during immune responses and how the same pathways are attenuated during the maintenance of …

Adaptive Divergence In The Thyroid Hormone Signaling Pathway In The Stickleback Radiation, Jun Kitano, Sean C. Lema, J. Adam Luckenbach, Seiichi Mori, Yui Kawagishi, Makoto Kusakabe, Penny Swanson, Catherine L. Peichel

Biological Sciences

During adaptive radiations, animals colonize diverse environments, which requires adaptation in multiple phenotypic traits. Because hormones mediate the dynamic regulation of suites of phenotypic traits, evolutionary changes in hormonal signaling pathways might contribute to adaptation to new environments. Here we report changes in the thyroid hormone signaling pathway in stream-resident ecotypes of threespine stickleback fish (Gasterosteus aculeatus), which have repeatedly evolved from ancestral marine ecotypes. Stream-resident fish exhibit a lower plasma concentration of thyroid hormone and a lower metabolic rate, which is likely adaptive for permanent residency in small streams. The thyroid-stimulating hormone-β2 (TSHβ …

Flowering Locus C Influences The Timing Of Shoot Maturation In Arabidopsis Thaliana, Laurie Mentzer, Tarah Yee, Tina Y. Wang, Edward Himelblau

Biological Sciences

No abstract provided.

Designing Marine Reserve Networks For Both Conservation And Fisheries Management, Steven D. Gaines, Crow White, Mark H. Carr, Stephen R. Palumbi

Biological Sciences

Marine protected areas (MPAs) that exclude fishing have been shown repeatedly to enhance the abundance, size, and diversity of species. These benefits, however, mean little to most marine species, because individual protected areas typically are small. To meet the larger-scale conservation challenges facing ocean ecosystems, several nations are expanding the benefits of individual protected areas by building networks of protected areas. Doing so successfully requires a detailed understanding of the ecological and physical characteristics of ocean ecosystems and the responses of humans to spatial closures. There has been enormous scientific interest in these topics, and frameworks for the design of …

The Role Of Oxidative Stress In Setting Thermal Tolerance Limits In Mytilus, Lars Tomanek

Biological Sciences

No abstract provided.

Nonylphenol In Marine Organisms In North American Estuaries: Trophic Chain Accumulation And Proteomic Responses, Lars Tomanek, J. M. Diehl, S. E. Johnson, K. Xia, S. J. Teh

Biological Sciences

No abstract provided.

Notonecta Exhibit Threat-Sensitive, Predator-Induced Dispersal, Shannon J. Mccauley, Locke Rowe

Biological Sciences

Dispersal is a central process determining community structure in heterogeneous landscapes, and species interactions within habitats may be a major determinant of dispersal. Although the effects of species interactions on dispersal within habitats have been well studied, how species interactions affect the movement of individuals between habitats in a landscape has received less attention. We conducted two experiments to assess the extent to which predation risk affects dispersal from an aquatic habitat by a flight-capable semi-aquatic insect (Notonecta undulata). Exposure to non-lethal (caged) fish fed conspecifics increased dispersal rates in N. undulata. Moreover, dispersal rate was positively correlated with the …

Pismo Beach Fecal Contamination Source Identification Study: Final Report, Christopher L. Kitts, Michael W. Black, Mark M. Moline, Marie Yeung, Alice K. Hamrick, Ian C. Robbins, Andrew A. Schaffner, Nathania I. Boutet

Biological Sciences

No abstract provided.

Sierra Nevada Red Fox (Vulpes Vulpes Necator): A Conservation Assessment, John D. Perrine, Lori A. Campbell, Gregory A. Green

Biological Sciences

One goal of the Sierra Nevada Forest Plan Amendment (SNFPA) 2001 and 2004 Records of Decision was to protect and recover native Sierra Nevada red fox (Vulpes vulpes necator) populations in the Sierra Nevada (USDA Forest Service 2001 p. 14). To accomplish this goal, the ROD commits the U.S. Department of Agriculture (USDA) Forest Service to completing a conservation assessment for the Sierra Nevada red fox in cooperation with other federal, state, and local agencies, as well as Tribal governments. This conservation assessment synthesizes the best available scientific information and thought concerning habitat relationships, population status and trends, historical and …