Life Sciences Commons^™

Release Of Avian Neurotensin In Response To Intraluminal Contents In The Duodenum Of Chickens, Teresa F. Degolier, Robert E. Carraway

Biological Sciences Faculty Publications

Peripheral and hepatic-portal plasma levels of neurotensin (NT) in fed and fasted chickens were determined using RIA. Portal levels of NT1-13 (fed = 61.3 ± 3.9 fmol/mL; fasted = 44.5 ± 3.9 fmol/mL) were significantly higher than peripheral levels (fed = 8.2 ± 3.3 fmol/mL; fasted = 7.8 ± 3.0 fmol/mL) collected from the wing vein, indicating that some NT is metabolized in the liver. Portal plasma levels of NT collected from fed birds were also significantly higher than portal plasma levels of NT collected from fasted birds. Neurotensin, as identified by HPLC, exhibited a 2-fold increase in plasma extracts …

Ecological Divergence Of A Novel Group Of Chloroflexus Strains Along A Geothermal Gradient, Michael L. Weltzer, Scott R. Miller

Biological Sciences Faculty Publications

Environmental gradients are expected to promote the diversification and coexistence of ecological specialists adapted to local conditions. Consistent with this view, genera of phototrophic microorganisms in alkaline geothermal systems generally appear to consist of anciently divergent populations which have specialized on different temperature habitats. At White Creek (Lower Geyser Basin, Yellowstone National Park), however, a novel, 16S rRNA-defined lineage of the filamentous anoxygenic phototroph Chloroflexus (OTU 10, phylum Chloroflexi) occupies a much wider thermal niche than other 16S rRNA-defined groups of phototrophic bacteria. This suggests that Chloroflexus OTU 10 is either an ecological generalist or, alternatively, a group of cryptic …

Wrangling Phosphoproteomic Data To Elucidate Cancer Signaling Pathways, Mark L. Grimes, Wan-Jui Lee, Laurens Van Der Maaten, Paul Shannon

Biological Sciences Faculty Publications

The interpretation of biological data sets is essential for generating hypotheses that guide research, yet modern methods of global analysis challenge our ability to discern meaningful patterns and then convey results in a way that can be easily appreciated. Proteomic data is especially challenging because mass spectrometry detectors often miss peptides in complex samples, resulting in sparsely populated data sets. Using the R programming language and techniques from the field of pattern recognition, we have devised methods to resolve and evaluate clusters of proteins related by their pattern of expression in different samples in proteomic data sets. We examined tyrosine …

A New Method For Identifying Stem-Like Cells In Esophageal Cancer Cell Lines, Michael Eric Geusz, Taghreed N. Almanaa, Roudabeh J. Jamasbi

Biological Sciences Faculty Publications

Cancer stem cells (CSCs) appear to resist chemo-radiotherapy and initiate tumor recurrence in patients. Isolation and further characterization of this subpopulation is important for targeting CSCs. Flow cytometry using Aldefluor, a fluorescent substrate of aldehyde dehydrogenase, has been used to isolate CSCs from various cancer cell lines. However, newtechniques are needed to locate and identify CSCs in culture for live-cell analyses such as fluorescence microscopy without introducing artifacts during cell sorting and to observe CSC and non-CSC interactions. Previously, we characterized a distinct CSC subpopulation within human esophageal cancer cell lines (ESCC). In this study we introduce the attached-cell Aldefluor …

Mitochondrial Dna Instability In Cells Lacking Aconitase Correlates With Iron Citrate Toxicity, Muhammad A. Farooq, Tammy M. Pracheil, Zhejun Dong, Fei Xiao, Zhengchang Liu

Biological Sciences Faculty Publications

Aconitase, the second enzyme of the tricarboxylic acid cycle encoded by ACO1 in the budding yeast Saccharomyces cerevisiae, catalyzes the conversion of citrate to isocitrate. aco1 Delta results in mitochondrial DNA (mtDNA) instability. It has been proposed that Aco1 binds to mtDNA and mediates its maintenance. Here we propose an alternative mechanism to account for mtDNA loss in aco1 Delta mutant cells. We found that aco1 Delta activated the RTG pathway, resulting in increased expression of genes encoding citrate synthase. By deleting RTG1, RTG3, or genes encoding citrate synthase, mtDNA instability was prevented in aco1 Delta mutant …

Mitochondrial Dna Instability In Cells Lacking Aconitase Correlates With Iron Citrate Toxicity, Zhengchang Liu, Fei Xiao, Zhejun Dong, Tammy Pracheil, Muhammad Farooq

Biological Sciences Faculty Publications

Aconitase, the second enzyme of the tricarboxylic acid cycle encoded by ACO1 in the budding yeast Saccharomyces cerevisiae, catalyzes the conversion of citrate to isocitrate. aco1Δ results in mitochondrial DNA (mtDNA) instability. It has been proposed that Aco1 binds to mtDNA and mediates its maintenance. Here we propose an alternative mechanism to account for mtDNA loss in aco1Δ mutant cells. We found that aco1Δ activated the RTG pathway, resulting in increased expression of genes encoding citrate synthase. By deleting RTG1, RTG3, or genes encoding citrate synthase, mtDNA instability was prevented in aco1Δ mutant cells. Increased activity of citrate synthase leads …

Looking For The Forest And The Trees: Exercises To Provoke Abstract Thinking, Boriana Marintcheva

Biological Sciences Faculty Publications

No abstract provided.

The Amino Acid Permeases Aap3 And Aap6 Are Involved In Root-Knot Nematode Parasitism Of Arabidopsis, Heather H. Marella, Erik Nielsen, Daniel P. Schachtman, Christopher G. Taylor

Biological Sciences Faculty Publications

The root-knot nematode, Meloidogyne incognita, is an obligate parasite which depends entirely on the host plant for its nutrition. Root-knot nematodes induce the formation of a highly specialized feeding site consisting of several giant cells surrounded by a network of vascular tissues. Nutrients, including amino acids and sugars, are transferred apoplastically from the vascular tissues to the feeding site. Using Arabidopsis thaliana lacking the vascular-expressed amino acid permeases (AAP) AAP3 or AAP6, we demonstrate that disruption of amino acid transport can affect nematode parasitism. Nematode infestation levels are significantly reduced on the aap3 and aap6 mutants. AAP3 and AAP6 …

Game-Based Curricula In Biology Classes: Multi-Level Assessment Of Science Learning, Troy D. Sadler, William L. Romine, Parker E. Stuart

Biological Sciences Faculty Publications

Video games played on computers, game consoles, tablets and smart phones have become a very popular medium in our society. A growing body of scholarship suggests that video games can support substantial learning (for reviews see Gee, 2007; Honey & Hilton, 2011; Squire, 2011). Research has documented ways in which games engage students deeply in thinking, learning, and collaboration (Gee, 2005). Evidence suggests that games can support development of critical thinking (Squire, 2006), creativity (Annetta, Cheng, & Holmes, 2010), and mastery and application of target concepts (Squire, 2011).

To 'Die Hel' And Back. Expeditions Of The Phylogeny Of World Tachinidae Project. Part I: Western Cape, South Africa, Pierfilippo Cerretti, James E. O'Hara, John O. Stireman Iii, Isaac S. Winkler, Ashley H. Kirk-Spriggs

Biological Sciences Faculty Publications

The “Phylogeny of World Tachinidae” project kicked off with an operational meeting in June 2012 at the Canadian National Collection of Insects (CNC) in Ottawa. Goals were discussed, work plans prepared, and of course the destinations and timing of major field expeditions were debated. During our three years of National Science Foundation funding we hope to gather fresh material for molecular analysis from all biogeographic regions of the world.

Progress Towards A Phylogeny Of World Tachinidae. Year 1, John O. Stireman Iii, James E. O'Hara, Michael C. Moulton, Pierfilippo Cerretti, Isaac S. Winkler

Biological Sciences Faculty Publications

D eveloping a structural phylogenetic framework for the family Tachinidae has been an interest of mine since I first started working on tachinids as a graduate student. It was then that I developed a new phylogenetic perspective with which to view the world, and many of the questions I wanted to ask of tachinids depended on some level of phylogenetic knowledge of them. I was surprised at the time that no one had attempted a broad quantitative phylogenetic analysis of the family, and a publication from my thesis work on the Exoristinae (Stireman 2002) became the first such study that …

Food Limitation As A Potentially Emerging Contributor To The Asian Vulture Crisis, Fakhar -I- Abbas, Thomas P. Rooney, Jibran Haider, Afsar Mian

Biological Sciences Faculty Publications

It was believed that the reason for decline in Asian vulture population is the drug, Diclofenac sodium (DFS), used in livestock. Even after declaring the DFS use banned by the government, apparent decrease in the population of vultures was reported. Alternate hypothesis was suggested that food limitation may be a cause of Asian vulture crisis in Pakistan. Very recent shifts in livestock utilization observed in Pakistan may present a significant barrier to vulture recovery. Increased livestock utilization is translated to fewer carcasses. Since 2005, no livestock carcasses were found in 1650 km transect in the habitat of vultures. Carcasses recorded …

Kinetic Models Reveal The In Vivo Mechanisms Of Mutagenesis In Microbes And Man, Barbara E. Wright, Karen H. Schmidt, Michael F. Minnick

Biological Sciences Faculty Publications

This review summarizes the evidence indicating that mutagenic mechanisms in vivo are essentially the same in all living cells. Unique metabolic reactions to a particular environmental stress apparently target specific genes for increased rates of transcription and mutation, resulting in higher mutation rates for those genes most likely to solve the problem. Kinetic models which have demonstrated predictive value are described and are shown to simulate mutagenesis in vivo in Escherichia coli, the p53 tumor suppressor gene, and somatic hypermutation. In all three models, direct correlations are seen between mutation frequencies and transcription rates. G and C nucleosides in single-stranded …

Thalassiosira Spp. Community Composition Shifts In Response To Chemical And Physical Forcing In The Northeast Pacific Ocean, P. Dreux Chappell, Leann P. Whitney, Traci L. Haddock, Susanne Menden-Deuer, Eric G. Roy, Mark L. Wells, Bethany D. Jenkins

Biological Sciences Faculty Publications

Diatoms are genetically diverse unicellular photosynthetic eukaryotes that are key primary producers in the ocean. Many of the over 100 extant diatom species in the cosmopolitan genus Thalassiosira are difficult to distinguish in mixed populations using light microscopy. Here, we examine shifts in Thalassiosira spp. composition along a coastal to open ocean transect that encountered a 3-month-old Haida eddy in the northeast Pacific Ocean. To quantify shifts in Thalassiosira species composition, we developed a targeted automated ribosomal intergenic spacer analysis (ARISA) method to identify Thalassiosira spp. in environmental samples. As many specific fragment lengths are indicative of individual Thalassiosira spp., …

Chemical Defense Of An Asian Snake Reflects Local Availability Of Toxic Prey And Hatchling Diet, D. A. Hutchinson, A. H. Savitzky, G. M. Burghardt, C. Nguyen, J. Meinwald, F. C. Schroeder, A. Mori

Biological Sciences Faculty Publications

Species that sequester toxins from prey for their own defense against predators may exhibit population-level variation in their chemical arsenal that reflects the availability of chemically defended prey in their habitat. Rhabdophis tigrinus is an Asian snake that possesses defensive glands in the skin of its neck (nuchal glands'), which typically contain toxic bufadienolide steroids that the snakes sequester from consumed toads. In this study, we compared the chemistry of the nuchal gland fluid of R.tigrinus from toad-rich and toad-free islands in Japan and determined the effect of diet on the nuchal gland constituents. Our findings demonstrate that captive-hatched juveniles …

Fire, Hurricane And Carbon Dioxide: Effects On Net Primary Production Of A Subtropical Woodland, Bruce A. Hungate, Frank P. Day, Paul Dijkstra, Benjamin D. Duval, C. Ross Hinkle, J. Adam Langley

Biological Sciences Faculty Publications

Disturbance affects most terrestrial ecosystems and has the potential to shape their responses to chronic environmental change. Scrub-oak vegetation regenerating from fire disturbance in subtropical Florida was exposed to experimentally elevated carbon dioxide (CO₂) concentration (+350ll^-1) using open-top chambers for 11yr, punctuated by hurricane disturbance in year 8. Here, we report the effects of elevated CO₂ on aboveground and belowground net primary productivity (NPP) and nitrogen (N) cycling during this experiment. The stimulation of NPP and N uptake by elevated CO₂ peaked within 2yr after disturbance by fire and hurricane, when soil nutrient availability was …

Seasonal Dynamics Of Mesodinium Rubrum In Chesapeake Bay, Matthew D. Johnson, Doane K. Stoecker, Harold G. Marshall

Biological Sciences Faculty Publications

The photosynthetic ciliate Mesodinium rubrum is a common member of coastal phytoplankton communities that is well adapted to low-light, turbid ecosystems. It supports the growth of, or competes with, harmful dinoflagellate species for cryptophyte prey, as well as being a trophic link to copepods and larval fish. We have compiled data from various sources (n = 1063), on the abundance and distribution of M. rubrum in Chesapeake Bay and its tributaries. Because M. rubrum relies on obtaining organelles from cryptophyte algae to maintain rapid growth, we also enumerated cryptophyte algae in the portion of these samples that we collected …

Ontogenetic Shifts In Resource Allocation: Colour Change And Allometric Growth Of Defensive And Reproductive Structures In The Caribbean Spiny Lobster Panulirus Argus, Joshua R. Anderson, Angelo J. Spadaro, J. Antonio Baeza, Donald C. Behringer

Biological Sciences Faculty Publications

Resource allocation theory predicts a disproportionately large allocation of resources to defensive structures during early ontogeny in organisms that are subject to more intense predation at smaller than at larger body sizes. We tested this prediction on the Caribbean spiny lobster Panulirus argus, which exhibits a negative relationship between predation risk and body size with a high natural mortality of smaller individuals. Independent allometric growth analyses demonstrated that numerous defensive structures (e.g. orbital horns, segments supporting the antenna, the tail fan) display negative allometric growth throughout ontogeny. We interpret these findings as lobsters investing disproportionately more resources to defensive …

Genetic Population Structure Of Us Atlantic Coastal Striped Bass (Morone Saxatilis), David T. Gauthier, Corinne A. Audemard, Jeanette E. L. Carlsson, Tanya L. Darden, Michael R. Denson, Kimberly S. Reece, Jens Carlsson

Biological Sciences Faculty Publications

Genetic population structure of anadromous striped bass along the US Atlantic coast was analyzed using 14 neutral nuclear DNA microsatellites. Young-of-the-year and adult striped bass (n = 1114) were sampled from Hudson River, Delaware River, Chesapeake Bay, North Carolina, and South Carolina. Analyses indicated clear population structure with significant genetic differentiation between all regions. Global multilocus F-ST was estimated at 0.028 (P < 0.001). Population structure followed an isolation-by-distance model and temporal sampling indicated a stable population structure more than 2 years at all locations. Significant structure was absent within Hudson River, whereas weak but significant genetic differences were observed between northern and southern samples in Chesapeake Bay. The largest and smallest effective striped bass population sizes were found in Chesapeake Bay and South Carolina, respectively. Coalescence analysis indicated that the highest historical gene flow has been between Chesapeake Bay and Hudson River populations, and that exchange has not been unidirectional. Bayesian analysis of contemporary migration indicated that Chesapeake Bay serves as a major source of migrants for Atlantic coastal regions from Albemarle Sound northward. In addition to examining population genetic structure, the data acquired during this project were capable of serving as a baseline for assigning fish with unknown origin to source region.

Conus: First Comprehensive Conservation Red List Assessment Of A Marine Gastropod Mollusc Genus, Howard Peters, Bethan C. O'Leary, Julie P. Hawkins, Kent E. Carpenter, Callum M. Roberts

Biological Sciences Faculty Publications

Marine molluscs represent an estimated 23% of all extant marine taxa, but research into their conservation status has so far failed to reflect this importance, with minimal inclusion on the authoritative Red List of the International Union for the Conservation of Nature (IUCN). We assessed the status of all 632 valid species of the tropical marine gastropod mollusc, Conus (cone snails), using Red List standards and procedures to lay the groundwork for future decadal monitoring, one of the first fully comprehensive global assessments of a marine taxon. Three-quarters (75.6%) of species were not currently considered at risk of extinction owing …

The Use Of Metagenomic Approaches To Analyze Changes In Microbial Communities, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

Microbes are the most abundant biological entities found in the biosphere. Identification and measurement of microorganisms (including viruses, bacteria, archaea, fungi, and protists) in the biosphere cannot be readily achieved due to limitations in culturing methods. A non-culture based approach, called “metagenomics”, was developed that enabled researchers to comprehensively analyse microbial communities in different ecosystems. In this study, we highlight recent advances in the field of metagenomics for analyzing microbial communities in different ecosystems ranging from oceans to the human microbiome. Developments in several bioinformatics approaches are also discussed in context of microbial metagenomics that include taxonomic systems, sequence databases, …

Age-Associated Metabolic And Morphologic Changes In Mitochondria Of Individual Mouse And Hamster Oocytes, Fatma Simsek-Duran, Fang Li, Wentia Ford, R. James Swanson, Howard W. Jones Jr., Frank J. Castora

Biological Sciences Faculty Publications

Background: In human oocytes, as in other mammalian ova, there is a significant variation in the pregnancy potential, with approximately 20% of oocyte-sperm meetings resulting in pregnancies. This frequency of successful fertilization decreases as the oocytes age. This low proportion of fruitful couplings appears to be influenced by changes in mitochondrial structure and function. In this study, we have examined mitochondrial biogenesis in both hamster (Mesocricetus auratus) and mouse (Mus musculus) ova as models for understanding the effects of aging on mitochondrial structure and energy production within the mammalian oocyte.

Methodology/Principal Findings: Individual metaphase …

Cumulative Response Of Ecosystem Carbon And Nitrogen Stocks To Chronic Co2 Exposure In A Subtropical Oak Woodland, Bruce A. Hungate, Paul Dijkstra, Zhuoting Wu, Benjamin D. Duval, Frank P. Day, Alisha L.P. Brown

Biological Sciences Faculty Publications

·Rising atmospheric carbon dioxide (CO₂) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO₂.

·We used open-top chambers to manipulate CO₂ during regrowth after fire, and measured C, N and tracer ¹⁵N in ecosystem components throughout the experiment.

·Elevated CO₂ increased plant C and tended to increase plant N but did not significantly increase whole-system C or N. Elevated CO₂ increased soil …

Direct And Legacy Effects Of Long-Term Elevated Co2 On Fine Root Growth And Plant-Insect Interactions, Peter Stiling, Daniel Moon, Anthony Rossi, Rebecca Forkner, Bruce A. Hungate, Frank P. Day, Rachel E. Schroeder, Bert Drake

Biological Sciences Faculty Publications

Increasing atmospheric CO₂ concentrations alter leaf physiology, with effects that cascade to communities and ecosystems. Yet, responses over cycles of disturbance and recovery are not well known, because most experiments span limited ecological time. We examined the effects of CO₂ on root growth, herbivory and arthropod biodiversity in a woodland from 1996 to 2006, and the legacy of CO₂ enrichment on these processes during the year after the CO₂ treatment ceased. We used minirhizotrons to study root growth, leaf censuses to study herbivory and pitfall traps to determine the effects of elevated CO₂ on arthropod …

Responses Of Amblyomma Americanum And Dermacentor Variabilis To Odorants That Attract Haematophagous Insects, A. L. Carr, R. M. Roe, C. Arellano, D. E. Sonenshine, C. Schal, C. S. Apperson

Biological Sciences Faculty Publications

Carbon dioxide (CO₂), 1-octen-3-ol, acetone, ammonium hydroxide, L-lactic-acid, dimethyl trisulphide and isobutyric acid were tested as attractants for two tick species, Amblyomma americanum and Dermacentor variabilis (Acari: Ixodidae), in doseresponse bioassays using Y-tube olfactometers. Only CO₂, acetone, 1-octen-3-ol and ammonium hydroxide elicited significant preferences from adult A. americanum, and only CO₂ was attractive to adult D. variabilis. Acetone, 1-octen-3-ol and ammonium hydroxide were separately evaluated at three doses against CO₂ (from dry ice) at a field site supporting a natural population of A. americanum nymphs and adults. Carbon dioxide consistently attracted the …

Corrected Numbers For Fish On Red List, Bruce B. Collette, Beth Polidoro, Kent Carpenter

Biological Sciences Faculty Publications

(First paragraph) Kelly Swing gives inaccurate numbers for marine fish species on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. He also mistakenly conflates the scientific process of species assessment for the Red List with the separate political process of IUCN member voting (Nature 494, 314; 2013).

Larval Connectivity And The International Management Of Fisheries, Andrew S. Kough, Claire B. Paris, Mark J. Butler Iv

Biological Sciences Faculty Publications

Predicting the oceanic dispersal of planktonic larvae that connect scattered marine animal populations is difficult, yet crucial for management of species whose movements transcend international boundaries. Using multi-scale biophysical modeling techniques coupled with empirical estimates of larval behavior and gamete production, we predict and empirically verify spatio-temporal patterns of larval supply and describe the Caribbean-wide pattern of larval connectivity for the Caribbean spiny lobster (Panulirus argus), an iconic coral reef species whose commercial value approaches $1 billion USD annually. Our results provide long sought information needed for international cooperation in the management of marine resources by identifying lobster larval connectivity …

Habitat Availability And Heterogeneity And The Indo-Pacific Warm Pool As Predictors Of Marine Species Richness In The Tropical Indo-Pacific, Jonnell C. Sanciangco, Kent E. Carpenter, Peter J. Etnoyer, Fabio Moretzsohn

Biological Sciences Faculty Publications

Range overlap patterns were observed in a dataset of 10,446 expert-derived marine species distribution maps, including 8,295 coastal fishes, 1,212 invertebrates (crustaceans and molluscs), 820 reef-building corals, 50 seagrasses, and 69 mangroves. Distributions of tropical Indo-Pacific shore fishes revealed a concentration of species richness in the northern apex and central region of the Coral Triangle epicenter of marine biodiversity. This pattern was supported by distributions of invertebrates and habitat-forming primary producers. Habitat availability, heterogeneity, and sea surface temperatures were highly correlated with species richness across spatial grains ranging from 23,000 to 5,100,000 km(2) with and without correction for autocorrelation. The …

Phytoplankton In Virginia Lakes And Reservoirs, Harold G. Marshall

Biological Sciences Faculty Publications

This study involves a phytoplankton summer/autumn survey in 46 Virginia lakes and reservoirs during 2010-2012. A total of 307 taxa were identified which included several filamentous and colonial cyanabacteria in bloom concentrations. With the exception of one natural lake, the other sites sampled represent impoundments created decades ago, with the majority presently classified as meso- or eutrophic. Among the cyanobacteria were 6 known toxin producers (Anabaena circinalis, Anabaena spiroides, Aphanizomenon flos-aquae, Cylindrospermopsis raciborskii, Limnothrix redekei, and Microcystis aeruginosa). The study characterizes phytoplankton populations in these aging freshwater habitats taken from a large number …

Cooperative Breeding And Long-Distance Dispersal: A Test Using Vagrant Records, Caroline L. Rusk, Eric L. Walters, Walter D. Koenig

Biological Sciences Faculty Publications

Cooperative breeding is generally associated with increased philopatry and sedentariness, presumably because short-distance dispersal facilitates the maintenance of kin groups. There are, however, few data on long-distance dispersal in cooperative breeders-the variable likely to be important for genetic diversification and speciation. We tested the hypothesis that cooperative breeders are less likely to engage in long-distance dispersal events by comparing records of vagrants outside their normal geographic range for matched pairs (cooperatively vs. non-cooperatively breeding) of North American species of birds. Results failed to support the hypothesis of reduced long-distance dispersal among cooperative breeders. Thus, our results counter the conclusion that …