Biology Commons^™

Radial Spoke Proteins Of Chlamydomonas Flagella, Pinfen Yang, Dennis R. Diener, Chun Yang, Takahiro Kohno, Gregory J. Pazour, Jennifer M. Dienes, Nathan S. Agrin, Stephen M. King, Winfield S. Sale, Ritsu Kamiya, Joel L. Rosenbaum, George B. Witman

Biological Sciences Faculty Research and Publications

The radial spoke is a ubiquitous component of `9+2' cilia and flagella, and plays an essential role in the control of dynein arm activity by relaying signals from the central pair of microtubules to the arms. The Chlamydomonas reinhardtii radial spoke contains at least 23 proteins, only 8 of which have been characterized at the molecular level. Here, we use mass spectrometry to identify 10 additional radial spoke proteins. Many of the newly identified proteins in the spoke stalk are predicted to contain domains associated with signal transduction, including Ca²⁺-, AKAP- and nucleotide-binding domains. This suggests that the …

Predicting Liana Crown Location From Stem Diameter In Three Panamanian Lowland Forests, Brian P. Kurzel, Stefan A. Schnitzer, Walter P. Carson

Biological Sciences Faculty Research and Publications

In three forests that differed in annual rainfall and seasonality, the probability of a liana with a stem ≥2.0 cm stem diameter reaching the canopy was >50 percent. Lianas reached the canopy at significantly smaller size‐classes (1.5 cm) in the wet aseasonal forest, suggesting that this estimate changes with forest type. Nevertheless, as a general rule, we suggest that 2.0 cm is the minium stem diameter to examine the abundance and diversity of canopy lianas or canopy competition between lianas and trees.

A Standard Protocol For Liana Censuses, Jeffrey J. Gerwing, Stefan A. Schnitzer, Robyn J. Burnham, Frans Bongers, Jérôme Chave, Saara J. Dewalt, Corneille E.N. Ewango, Robin Foster, David Kenfack, Miguel Martinez-Ramos, Marc P.E. Parren, Narayanaswamy Parthasarathy, Diego R. Perez-Salicrup, Francis E. Putz, Duncan W. Thomas

Biological Sciences Faculty Research and Publications

A recent increase in published studies of lianas has been paralleled by a proliferation of protocols for censusing lianas. This article seeks to increase uniformity in liana inventories by providing specific recommendations for the determination of which taxa to include, the location of diameter measurement points on individual stems, the setting of minimum stem diameter cutoffs, the treatment of multiple‐stemmed and rooted clonal groups, and the measurement of noncylindrical stems. Use of more uniform liana censusing protocols may facilitate comparison of independently collected data sets and further our understanding of global patterns in liana abundance, diversity, biomass, and dynamics.

Mercury Concentrations In South Texas Game Fishes, E. Anthony Reisinger

Theses and Dissertations - UTB/UTPA

Mercury (Hg) is one of the most ubiquitous and controversial metals in the world primarily due to the toxicity of the organic form of the metal, methylmercury (MeHg). MeHg is a neurotoxin at high levels, known to manifest its effects on humans primarily through consumption of certain fish and marine mammals, which tend to bioaccumulate MeHg in their tissues over time. Increased fish consumption and, thus, mercury intake in residents of coastal areas necessitates a better awareness of MeHg content in game fish species, thus the subject of this study.

Three hundred thirty-nine tissue samples were taken from 19 south …

Sex Determination Of Red-Tailed Hawks (Buteo Jamaicensis Calurus) Using Dna Analysis And Morphometrics, Kara C. Donohue, Alfred M. Dufty Jr.

Biology Faculty Publications and Presentations

Currently the sex of Red-tailed hawks (Buteo jamaicensis) cannot be determined by in-hand methods. Males and females do not differ in plumage and overlap in size. During migration, we collected feather samples and morphological measurements from birds at four sites in the Western United States. Sex was determined for individual birds using sex-specific DNA markers and Polymerase Chain Reaction was used to identify these DNA markers. Through Discriminant Function Analysis, we created equations for determining the sex of Red-tailed hawks using in-hand measurements based on the DNA-determined sexes. We formed two equations, one for adults, which was 98% …

Induction Of Temperate Cyanophage As-1 By Heavy Metal - Copper, Lee H. Lee, Doris Lui, Patricia J. Platner, Shi Fang Hsu, Tin Chun Chu, John J. Gaynor, Quinn C. Vega, Bonnie K. Lustigman

Department of Biology Faculty Scholarship and Creative Works

Background: It has been reported that some marine cyanophage are temperate and can be induced from a lysogenic phase to a lytic phase by different agents such as heavy metals. However, to date no significant reports have focused on the temperate nature of freshwater cyanophage/cyanobacteria. Previous experiments with cyanophage AS-1 and cyanobacteria Anacystis nidulans have provided some evidence that AS-1 may have a lysogenic life cycle in addition to the characterized lytic cycle. Results: In this study, the possible temperate A. nidulans was treated with different concentrations of heavy metal-copper. CuSO4 with concentrations of 3.1 × 10^-3 M, 3.1 …

Oaz Regulates Bone Morphogenetic Protein Signaling Through Smad6 Activation, Manching Ku, Shavonne Howard, Weihua Ni, Giorgio Lagna, Akiko Hata

Biology

The intensity and duration of activation of a signal transduction system are important determinants of the specificity of the cellular response to the stimulus. It is unclear how different cells can generate a signal of varying intensity and duration in response to the same cytokine. We investigated the role of the transcriptional activator and Smad1/4 cofactor OAZ in regulating bone morphogenetic protein (BMP) signaling. We demonstrate that upon BMP4 stimulation, an OAZ-Smad1/4 complex binds to and activates the gene encoding Smad6, a specific inhibitor of the BMP pathway. Removal of endogenous OAZ from pluripotent embryonal carcinoma cells prevents the induction …

Optimal Foraging: Some Theoretical Explorations, Eric Charnov, Gordon H. Orians

Biology Faculty & Staff Publications

This book had its genesis in a rather disorganized and poorly conceived lecture on optimal foraging theory that one of us (GHO) gave to an advanced ecology class during the winter of 1971.The deficiencies in that treatment, combined with the obvious potential of an improved conceptualization and analysis of the problem, led to the formation of a small seminar on optimal foraging theory attended by Charles Fowler, Nolan Pearson and ourselves. This seminar, which extended over two academic quarters, produced the basic fine-grained foraging models and some hints about wider applications of the results. We both found ourselves independently stimulated …

The Distress Calls Of Leptodactylus Chaquensis Cei, 1950 And Leptodactylus Elenae Heyer, 1978 (Anura: Leptodactylidae), José M. Padial, Rafael O. De Sá, Ignacio De La Riva

Biology Faculty Publications

We describe the distress calls of Leptodactylus chaquensis and Leptodactylus elenae. They each consist of a single, long, tonal sound with complex harmonic structure and complex frequency modulation. The distress calls of both species are different from their respective advertisement calls. Moreover, there are also clear interspecific differences. Harmonic frequencies in L. elenae are higher, there are fewer emphasized harmonics and the call is shorter and repeated at a higher rate (sometimes paired) than the call of L. chaquensis. Call duration, call rate, and position of the dominant harmonic change with the strength of the stimulus that the …

Regulation Of Cytoplasmic Dynein Atpase By Lis1, Mariano T. Mesngon, Cataldo Tarricone, Sachin Hebbar, Aimee Guillotte, E. William Schmitt, Lorene Lanier, Andrea Musacchio, Stephen J. King, Deanna S. Smith

Faculty Publications

Mutations in Lis1 cause classical lissencephaly, a developmental brain abnormality characterized by defects in neuronal positioning.Over the last decade, a clear link has been forged between Lis1 and the microtubule motor cytoplasmic dynein. Substantial evidenceindicates that Lis1 functions in a highly conserved pathway with dynein to regulate neuronal migration and other motile events. Yeasttwo-hybrid studies predict that Lis1 binds directly to dynein heavy chains (Sasaki et al., 2000; Tai et al., 2002), but the mechanistic significance of this interaction is not well understood. We now report that recombinant Lis1 binds to native brain dynein and significantly increases the microtubule-stimulated enzymatic …

Phylogenetic Analyses Of Mtdna Sequences Reveal Three Cryptic Lineages In The Widespread Neotropical Frog Leptodactylus Fuscus (Schneider, 1799) (Anura, Leptodactylidae), Arley Camargo, Rafael O. De Sá, W. Ronald Heyer

Biology Faculty Publications

Leptodactylus fuscus is a neotropical frog ranging from Panamá to Argentina, to the east of the Andes mountains, and also inhabiting Margarita, Trinidad, and the Tobago islands. We performed phylogenetic analyses of 12S rRNA, 16S rRNA, tRNA-Leu, and ND1 mitochondrial (mt) DNA sequences from specimens collected across the geographic distribution of L. fuscus to examine two alternative hypotheses: (i) L. fuscus is a single, widely distributed species, or (ii) L. fuscus is a species complex. We tested statistically for geographic association and partitioning of genetic variation among mtDNA clades. The mtDNA data supported the hypothesis of several cryptic species within …

Double Knockouts Of Phospholipases Dζ1 And Dζ2 In Arabidopsis Affect Root Elongation During Phosphate-Limited Growth But Do Not Affect Root Hair Patterning, Xuemin Wang, Maoyin Li, Chunbo Qin, Ruth Welti

Biology Department Faculty Works

Root elongation and root hair formation are important in nutrient absorption. We found that two Arabidopsis (Arabidopsis thaliana) phospholipase Ds (PLDs), PLDζ1 and PLDζ2, were involved in root elongation during phosphate limitation. PLDζ1 and PLDζ2 are structurally different from the majority of plant PLDs by having phox and pleckstrin homology domains. Both PLDζs were expressed more in roots than in other tissues. It was reported previously that inducible suppression or inducible overexpression of PLDζ1 affected root hair patterning. However, gene knockouts of PLDζ1, PLDζ2, or the double knockout of PLDζ1 and PLDζ2 showed no effect on root hair formation. The …

Mutations Conferring Aminoglycoside And Spectinomycin Resistance In Borrelia Burgdorferi, Daniel Criswell, Virginia L. Tobiason, J. Stephen Lodmell, D. Scott Samuels

Biological Sciences Faculty Publications

We have isolated and characterized in vitro mutants of the Lyme disease agent Borrelia burgdorferi that are resistant to spectinomycin, kanamycin, gentamicin, or streptomycin, antibiotics that target the small subunit of the ribosome. 16S rRNA mutations A1185G and C1186U, homologous to Escherichia coli nucleotides A1191 and C1192, conferred > 2,200-fold and 1,300-fold resistance to spectinomycin, respectively. A 16S rRNA A1402G mutation, homologous to E. coli A1408, conferred > 90-fold resistance to kanamycin and > 240-fold resistance to gentamicin. Two mutations were identified in the gene for ribosomal protein S12, at a site homologous to E. coli residue Lys-87, in mutants selected in streptomycin. …

Glucocorticoids Exacerbate Obesity And Insulin Resistance In Neuron-Specific Proopiomelanocortin-Deficient Mice, James L. Smart, Virgine Tolle, Malcolm J. Low

Faculty Publications - Department of Biological & Molecular Science

Null mutations of the proopiomelanocortin gene (Pomc–/–) cause obesity in humans and rodents, but the contributions of central versus pituitary POMC deficiency are not fully established. To elucidate these roles, we introduced a POMC transgene (Tg) that selectively restored peripheral melanocortin and corticosterone secretion in Pomc–/– mice. Rather than improving energy balance, the genetic replacement of pituitary POMC in Pomc–/–Tg+ mice aggravated their metabolic syndrome with increased caloric intake and feed efficiency, reduced oxygen consumption, increased subcutaneous, visceral, and hepatic fat, and severe insulin resistance. Pair-feeding of Pomc–/–Tg+ mice to the daily intake of lean controls normalized their rate of …

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.

Contribution Of Msh2 And Msh6 Subunits To The Asymmetric Atpase And Dna Mismatch Binding Activities Of Saccharomyces Cerevisiae Msh2–Msh6 Mismatch Repair Protein, Edwin Antony, Sapna Khubchandani, Siying Chen, Manju M. Hingorani

Biological Sciences Faculty Research and Publications

Previous analyses of both Thermus aquaticus MutS homodimer and Saccharomyces cerevisiae Msh2–Msh6 heterodimer have revealed that the subunits in these protein complexes bind and hydrolyze ATP asymmetrically, emulating their asymmetric DNA binding properties. In the MutS homodimer, one subunit (S₁) binds ATP with high affinity and hydrolyzes it rapidly, while the other subunit (S₂) binds ATP with lower affinity and hydrolyzes it at an apparently slower rate. Interaction of MutS with mismatched DNA results in suppression of ATP hydrolysis at S₁—but which of these subunits, S₁ or S₂, makes specific contact …

Linking Direct And Indirect Data On Dispersal: Isolation By Slope In A Headwater Stream Salamander, Winsor H. Lowe, Gene E. Likens, Mark A. Mcpeek, Don C. Buso

Biological Sciences Faculty Publications

There is growing recognition of the need to incorporate information on movement behavior in landscape-scale studies of dispersal. One way to do this is by using indirect indices of dispersal (e.g., genetic differentiation) to test predictions derived from direct data on movement behavior. Mark–recapture studies documented upstream-biased movement in the salamander Gyrinophilus porphyriticus (Plethodontidae). Based on this information, we hypothesized that gene flow in G. porphyriticus is affected by the slope of the stream. Specifically, because the energy required for upstream dispersal is positively related to slope, we predicted gene flow to be negatively related to change in elevation between …

An Introduced Predator Alters Aleutian Island Plant Communities By Thwarting Nutrient Subsidies, John L. Maron, James A. Estes, Donald A. Croll, Eric M. Danner, Sarah C. Elmendorf, Stacey L. Buckelew

Biological Sciences Faculty Publications

The ramifying effects of top predators on food webs traditionally have been studied within the framework of trophic cascades. Trophic cascades are compelling because they embody powerful indirect effects of predators on primary production. Although less studied, indirect effects of predators may occur via routes that are not exclusively trophic. We quantified how the introduction of foxes onto the Aleutian Islands transformed plant communities by reducing abundant seabird populations, thereby disrupting nutrient subsidies vectored by seabirds from sea to land. We compared soil and plant fertility, plant biomass and community composition, and stable isotopes of nitrogen in soil, plants, and …

Photo Processes On Self-Associated Cationic Porphyrins And Plastocyanin Complexes 1. Ligation Of Plastocyanin Tyrosine 83 Onto Metalloporphyrins And Electron-Transfer Fluorescence Quenching, Hewa Anula, Eugene Myshkin, Anton Guliaev, Charles Luman, Evgeny Danilov, Felix Castellano, George S. Bullerjahn, Michael Rogers

Biological Sciences Faculty Publications

The spectroscopic properties of the self-associated complexes formed between the anionic surface docking site of spinach plastocyanin and the cationic metalloporphyrins, in which the tyrosine 83 (Y83) moiety is placed just below the docking site, tetrakis(N-methyl-4-pyridyl)porphyrin (Pd(II)TMPyP4+ and Zn(II)TMPyP4+), have been studied and reported herein. The fluorescence quenching phenomenon of the self-assembled complex of Zn(II)TMPyP4+/plastocyanin has also been discovered. The observed red-shifting of the Soret and Q-bands of the UV-visible spectra, ca. 9 nm for Pd(II)TMPyP4+/plastocyanin and ca. 6 nm for the Zn(II)TMPyP4+/ plastocyanin complexes, was explained in terms of exciton theory coupled with the Gouterman model. Thus, the hydroxyphenyl …

A Three-Dimensional Functional Assessment Of Heart And Vessel Development In The Larva Of The Zebrafish (Danio Rerio), Brian Bagatto, Warren Burggren

Biology Faculty Research

There has been considerable recent interest in the development of the circulation in the zebrafish. Optical techniques typically used to visualize changes in heart size allow measurement of stroke volume during early vertebrate development, but this approach is complicated in zebrafish larvae because of the heart's irregular shape and its significant change in morphology during the first 6 d of development. By use of a three-dimensional integration of the early zebrafish heart and vessels, we have greatly reduced measurement error of stroke volume and cardiac output and have determined the cross-sectional growth of major vessels in the developing zebrafish larvae. …

Oncostatin M Differentially Regulates Cxc Chemokines In Mouse Cardiac Fibroblasts, Pascal J. Lafontant

Biology Faculty publications

Ischemia-reperfusion injury in the heart is characterized by marked infiltration of neutrophils in the myocardial interstitial space. Studies in human, canine, and murine models have revealed oncostatin M (OSM) expression in infiltrating leukocytes. In an effort to assess possible roles of OSM in the myocardium, we used cardiac fibroblasts (mCFs) isolated from adult mouse heart to determine whether recombinant murine OSM regulates the synthesis and release of MIP2/ CXCL2, KC/CXCL1, and LIX/CXCL5, which are three potent neutrophil chemoattractants in the mouse. Our results demonstrate that mCFs express OSM receptors and that, within the IL-6 cytokine family, OSM uniquely induces significant …

Linking Direct And Indirect Data On Dispersal: Isolation By Slope In A Headwater Stream Salamander, Winsor H. Lowe, Gene E. Likens, Mark A. Mcpeek, Don C. Buso

Dartmouth Scholarship

There is growing recognition of the need to incorporate information on movement behavior in landscape-scale studies of dispersal. One way to do this is by using indirect indices of dispersal (e.g., genetic differentiation) to test predictions derived from direct data on movement behavior. Mark–recapture studies documented upstream-biased movement in the salamander Gyrinophilus porphyriticus (Plethodontidae). Based on this information, we hypothesized that gene flow in G. porphyriticus is affected by the slope of the stream. Specifically, because the energy required for upstream dispersal is positively related to slope, we predicted gene flow to be negatively related to change in elevation between …

Relationships Of Habitat Characteristics To The Relative Abundance Of Native And Invasive Amphipods In Western Lake Erie, James P. Duggan

Master's Theses and Doctoral Dissertations

No abstract provided.

Transport Of E. Coli In Egyptian Agricultural Soils As A Result Of Reclaimed Wastewater Use For Irrigation, Aimen Badawy

Archived Theses and Dissertations

Limited water resources are one of the main constraints to socio-economic development and even a source of insecurity at national and regional levels. The increasing demand for water in the agricultural sector stimulated the use of reclaimed wastewater for irrigation. Comprehending health and environment risks resulting from contaminants that may often be associated with reclaimed wastewater will lead to the sustainable use of this resource, as well as the conservation of other water resources.

In the present study the fate and transport of one important wastewater constituent, namely E. Coli bacteria, in three Egyptian soils of typical agricultural use was …

Variation In The Innate And Acquired Arms Of The Immune System Among Five Shorebird Species, Luisa Mendes, Theunis Piersma, Dennis Hasselquist, Kevin Matson, Robert Ricklefs

Biology Department Faculty Works

To contribute to an understanding of the evolutionary processes that shape variation in immune responses, we compared several components of the innate and acquired arms of the immune system in five related, but ecologically diverse, migratory shorebirds (ruff Philomachus pugnax L., ruddy turnstone Arenaria interpres L., bar-tailed godwit Limosa lapponica L., sanderling Calidris alba Pallas and red knotC. canutus L.). We used a hemolysis-hemagglutination assay in free-living shorebirds to assess two of the innate components (natural antibodies and complement-mediated lysis), and a modified quantitative enzyme-linked immunosorbent assay in birds held in captivity to assess the acquired component (humoral antibodies against …

The Impacts Of Climate Change In Coastal Marine Systems, Christopher D.G. Harley, A. Randall Hughes, Kristin M. Hultgren, Benjamin G. Miner, Cascade J.B. Sorte, Carol S. Thornber, Laura F. Rodriguez, Lars Tomanek, Susan L. Williams

Biological Sciences

Anthropogenically induced global climate change has profound implications for marine ecosystems and the economic and social systems that depend upon them. The relationship between temperature and individual performance is reasonably well understood, and much climate-related research has focused on potential shifts in distribution and abundance driven directly by temperature. However, recent work has revealed that both abiotic changes and biological responses in the ocean will be substantially more complex. For example, changes in ocean chemistry may be more important than changes in temperature for the performance and survival of many organisms. Ocean circulation, which drives larval transport, will also change, …

Physiological Effects On Demography: A Long‐Term Experimental Study Of Testosterone’S Effects On Fitness, W. Reed, M. Clark, P. Parker, S. Raouf, N. Arguedas, D. Monk, E. Snajdr, V. Nolan, E. Ketterson

Biology Department Faculty Works

Understanding physiological and behavioral mechanisms underlying the diversity of observed life‐history strategies is challenging because of difficulties in obtaining long‐term measures of fitness and in relating fitness to these mechanisms. We evaluated effects of experimentally elevated testosterone on male fitness in a population of dark‐eyed juncos studied over nine breeding seasons using a demographic modeling approach. Elevated levels of testosterone decreased survival rates but increased success of producing extra‐pair offspring. Higher overall fitness for testosterone‐treated males was unexpected and led us to consider indirect effects of testosterone on offspring and females. Nest success was similar for testosterone‐treated and control males, …

Effects Of Prescribed Burning On Breeding Bird Populations Of The Daniel Boone National Forest Pioneer Weapons Area, Jimmy Mains

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Jimmy Mains on January 3, 2006.

The Genetic Outcomes Of Sex And Recombination In Long-Term Functionally Parthenogenetic Lineages Of Australian Sitobion Aphids, Alex C. C. Wilson, Paul Sunnucks

Biology Articles and Papers

The typical life cycle of an aphid is cyclical parthenogenesis which involves the alternation of sexual and asexual reproduction. However, aphid life cycles, even within a species, can encompass everything on a continuum from obligate sexuality, through facultative sexuality to obligate asexuality. Loss of the sexual cycle in aphids is frequently associated with the introduction of a new pest and can occur for a number of environmental and genetic reasons. Here we investigate loss of sexual function in Sitobion aphids in Australia. Specifically, we aimed to determine whether an absence of sexual reproduction in Australian Sitobion results from genetic loss …

Climate Change And Its Effects On Polar Bears, Alex C. Jospe, Bethany C. Peck, Emily Sinnott

Undergraduate Research Symposium (UGRS)

Polar bears are key indicators of the effects of climate change on the arctic ecosystem, because their existence is directly related to the sea ice habitat, where they hunt. As the Arctic continues to warm, their habitat will be reduced further and local extinction is likely to occur, especially in southern populations.