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Dissolved Organic Matter Influences The Timing Of Embryonic Development Of The Purple Sea Urchin, Strongylocentrotus Purpuratus., Corbin J. Hodges

Master's Theses

Marine dissolved organic matter (DOM) comprises one of the largest carbon reservoirs on earth and has long been considered a potential energy source for marine invertebrates. The importance of DOM transport has been adequately demonstrated for unicellular organisms, where DOM can meet 100% of an organisms energy needs, but the effects of DOM uptake for marine metazoans are less well understood. In this study, three general areas involving the influence of DOM transport to marine invertebrates were explored. First, we assessed the effects of using seawater exposed to high intensity ultraviolet radiation (UVR) on the study organism; embryos of the …

The Role Of Spatial And Genetic Modeling To Biogeography, Dolly Lyne Crawford

Biology ETDs

One of the most persistent challenges in biology is explaining the distribution of animal taxa. Quantitative explanations for the distribution of organisms are challenged by the complexity of factors that potentially limit a species range, including topography, ecology, climate and biology. Because of limits on data and approaches, early biogeographers were hampered in their ability to explain patterns. Here, I benefit from two primary developments in biogeography. My research draws from the accumulation of data across several scientific disciplines and advances in spatial and statistical approaches to examine the distribution of animal taxa within an integrative biogeography framework. I combine …

Statistical Methods In Microarrays And High-Throughput Flow Cytometry, Osorio Meirelles

Biology ETDs

Abstract-I

Background: Heterogeneous cell populations have previously been described as noisy. However, recent studies have demonstrated that heterogeneity can be biologically significant. We present here an approach for rapid and complete identification of heterogeneous cell populations from high-throughput flow cytometry data. We have developed a novel measure Slope Differentiation Identification (SDI) using flow cytometry-based protein expression, quantifying the rate of change in protein expression between two conditions (exponential and stationary phase) of yeast cells, as a function of cell size or cell granularity.

Results: SDI had superior Gene Ontology enrichment when compared with other approaches such as k-means clustering and …

The Ecology Of The Peaks Of Otter Salamander (Plethodon Hubrichti) In Sympatry With The Eastern Red-Backed Salamander (Plethodon Cinereus), Norman Reichenbach, Andrew Kniowski

Faculty Publications and Presentations

The Peaks of Otter Salamander, Plethodon hubrichti, is found along a 19 km length of the Blue Ridge Mountains, Virginia, USA, often in sympatry with the Eastern Red-backed Salamander, P. cinereus. In a sympatric area of Bedford County, Virginia, we conducted a mark-recapture study on a 10 × 10 m site. Surface densities of salamanders increased as the number of days without precipitation prior to a collection event increased. This suggests vertical movements in response to surface moisture. When salamanders returned to the surface after rain, individuals appeared to “shuffle” between rocks and likely, leaf litter. That is, we were …

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 …

Population Ecology And Reproductive Biology Of The Diamondback Watersnake, Nerodia Rhombifer (Serpentes: Colubridae), In Southernmost Texas, Ruben D. Zamora

Theses and Dissertations - UTB/UTPA

Nerodia rhombifer is a polytypic, semi-aquatic snake with a broad geographical distribution ranging from the American Midwest southward to Chiapas, Mexico. Although relatively abundant throughout much of its range, few ecological studies of the species have been conducted. This study provides basic population ecology information in a subtropical habitat. Population data were obtained in a mark-recapture study at Santa Ana National Wildlife Refuge, Hidalgo County, Texas, from August 1995 to December 1998. Specimens taken elsewhere in Hidalgo County provided information on the reproductive biology. This study provides the first absolute density estimates from anywhere within the species’ range. Quantitative information …

Conservation Genetics And Systematics Of Several Turtles Species In The Southeastern United States, Joshua Robert Ennen

Dissertations

Chelonians (i.e., turtles) are an imperiled group of reptiles with about 66% of the recognized species listed as threatened by the IUCN. Most chelonian species have a unique set of life history traits (i.e., longevity, delayed sexual maturity, and low juvenile survivorship), which makes their populations exceedingly sensitive to increases in adult and juvenile moralities. With numerous anthropogenic effects (e.g., habitat alteration, exploitation, and over harvesting) negatively influencing mortality rates, chelonians have experienced global precipitous declines and extinctions.

This dissertation focuses on species within two chelonian genera, Gopherus and Graptemys. Although these two genera are vastly different ecologically, they are …

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, …

Prothonotary Warbler (Protonotaria Citrea) Plumage As An Indicator For Infection: The Relationship Between Haemosporidia Infection And Breast Feather Reflectance In A Neotropical Migrant Passerine, Robert Fithian

Theses and Dissertations

Yellow avian plumage is a direct result of carotenoid pigments obtained in a bird’s diet and may act as an indicator for individual health, parasite resistance, and status. This study describes breast feather reflectance of adult Prothonotary Warblers (Protonotaria citrea) (n=169), insectivorous Neotropical migrant passerines, throughout the Ultraviolet (UV) and human visible light spectra and examines the relationship between Haemosporidia (pathogen causing Avian Malaria) infection and feather reflectance (n=41). Reflectance was characterized using a Principle Component Analysis evaluating Intensity, Brightness, Hue, UV Intensity, UV Brightness, and UV Chroma. UV and visible light reflectance was higher in birds sampled earlier in …

Ceramide Kinase Regulates Phospholipase C And Phosphatidylinositol 4, 5, Bisphosphate In Phototransduction, Ujjaini Dasgupta, Takeshi Bamba, Salvatore Chiantia, Pusha Karim, Ahmad N. Abou Tayoun

Dartmouth Scholarship

Phosphoinositide-specific phospholipase C (PLC) is a central effector for many biological responses regulated by G-protein-coupled receptors including Drosophila phototransduction where light sensitive channels are activated downstream of NORPA, a PLCbeta homolog. Here we show that the sphingolipid biosynthetic enzyme, ceramide kinase, is a novel regulator of PLC signaling and photoreceptor homeostasis. A mutation in ceramide kinase specifically leads to proteolysis of NORPA, consequent loss of PLC activity, and failure in light signal transduction. The mutant photoreceptors also undergo activity-dependent degeneration. Furthermore, we show that a significant increase in ceramide, resulting from lack of ceramide kinase, perturbs the membrane microenvironment of …

Susceptibility Of Caenorhabditis Elegans To Burkholderia Infection Depends On Prior Diet And Secreted Bacterial Attractants, Vaughn S. Cooper, Wendy A. Carlson, John J. Lipuma

Molecular, Cellular & Biomedical Sciences

The nematode Caenorhabditis elegans may be killed by certain pathogenic bacteria and thus is a model organism for studying interactions between bacteria and animal hosts. However, growing nematodes on prey bacteria may influence their susceptibility to potential pathogens. A method of axenic nematode culture was developed to isolate and quantify interactions between C. elegans and potentially pathogenic strains of the Burkholderia cepacia complex. Studying these dynamics in liquid solution rather than on agar surfaces minimized nematode avoidance behavior and resolved more differences among isolates. Most isolates of B. cenocepacia, B. ambifaria and B. cepacia caused 60-80% mortality of nematodes after …

Quantifying And Resolving Multiple Vector Transformants In S. Cerevisiae Plasmid Libraries, Thomas C. Scanlon, Elizabeth C. Gray, Karl E. Griswold

Dartmouth Scholarship

In addition to providing the molecular machinery for transcription and translation, recombinant microbial expression hosts maintain the critical genotype-phenotype link that is essential for high throughput screening and recovery of proteins encoded by plasmid libraries. It is known that Escherichia coli cells can be simultaneously transformed with multiple unique plasmids and thusly complicate recombinant library screening experiments. As a result of their potential to yield misleading results, bacterial multiple vector transformants have been thoroughly characterized in previous model studies. In contrast to bacterial systems, there is little quantitative information available regarding multiple vector transformants in yeast. Saccharomyces cerevisiae is the …

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. …

Immunisation With A Multivalent, Subunit Vaccine Reduces Patent Infection In A Natural Bovine Model Of Onchocerciasis During Intense Field Exposure, Benjamin L. Makepeace, Siv Aina Jensen, Sandra J. Laney, Charles K. Nfon, Leo M. Njongmeta, Vincent N. Tanya, Steven A. Williams, Albert E. Bianco, Alexander J. Trees

Biological Sciences: Faculty Publications

Human onchocerciasis, caused by the filarial nematode Onchocerca volvulus, is controlled almost exclusively by the drug ivermectin, which prevents pathology by targeting the microfilariae. However, this reliance on a single control tool has led to interest in vaccination as a potentially complementary strategy. Here, we describe the results of a trial in West Africa to evaluate a multivalent, subunit vaccine for onchocerciasis in the naturally evolved host-parasite relationship of Onchocerca ochengi in cattle. Na ̈ıve calves, reared in fly-proof accommodation, were immunised with eight recombinant antigens of O. ochengi, administered separately with either Freund’s adjuvant or alum. The selected antigens …

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 …

The Importance Of Fallback Foods In Primate Ecology And Evolution, Paul J. Constantino, Barth W. Wright

Biological Sciences Faculty Research

The role of fallback foods in shaping primate ranging, socioecology, and morphology has recently become a topic of particular interest to biological anthropologists. Although the use of fallback resources has been noted in the ecological and primatological literature for a number of decades, few attempts have been made to define fallback foods or to explore the utility of this concept for primate evolutionary biologists and ecologists. As a preface to this special issue of the American Journal of Physical Anthropology devoted to the topic of fallback foods in primate ecology and evolution, we discuss the development and use of the …

Exhaustive Exercise Training Enhances Aerobic Capacity In American Alligator (Alligator Mississippiensis), John Eme, Tomasz Owerkowicz, June Gwalthney, Jason M. Blank, Bryan C. Rourke, James W. Hicks

Biological Sciences

The oxygen transport system in mammals is extensively remodelled in response to repeated bouts of activity, but many reptiles appear to be ‘metabolically inflexible’ in response to exercise training. A recent report showed that estuarine crocodiles (Crocodylus porosus) increase their maximum metabolic rate in response to exhaustive treadmill training, and in the present study, we confirm this response in another crocodilian, American alligator (Alligator mississippiensis). We further specify the nature of the crocodilian training response by analysing effects of training on aerobic [citrate synthase (CS)] and anaerobic [lactate dehydrogenase (LDH)] enzyme activities in selected skeletal muscles, …

Surgical Removal Of Right-To-Left Cardiac Shunt In The American Alligator (Alligator Mississippiensis) Causes Ventricular Enlargement But Does Not Alter Apnoea Or Metabolism During Diving, John Eme, June Gwalthney, Jason M. Blank, Tomasz Owerkowicz, Gildardo Barron, James W. Hicks

Biological Sciences

Crocodilians have complete anatomical separation between the ventricles, similar to birds and mammals, but retain the dual aortic arch system found in all non-avian reptiles. This cardiac anatomy allows surgical modification that prevents right-to-left (R–L) cardiac shunt. A R–L shunt is a bypass of the pulmonary circulation and recirculation of oxygen-poor blood back to the systemic circulation and has often been observed during the frequent apnoeic periods of non-avian reptiles, particularly during diving in aquatic species. We eliminated R–L shunt in American alligators (Alligator mississippiensis) by surgically occluding the left aorta (LAo; arising from right ventricle) upstream and …

The Development And Role Of Peripheral Auditory Structures In Otocinclus Affinis, Sri Kiran Kumar Reddy Botta

Masters Theses & Specialist Projects

Loricariidae is a very diverse family of catfishes found primarily in the Amazon River basin. These catfishes have a unique characteristic feature of having fenestrae (holes) in the skull region (compound pterotic bone) adjacent to their bi-lobed swim bladder. Since the swim bladders and the compound pterotic may act as an external ear for hearing in this taxon, I hypothesized that these swim bladders structures have an acoustical functional in the loricariid Otocinclus affinis. In order to understand the development of these structures in O. affinis, I first monitored the ontogeny of the compound pterotic bone by clearing …

E Unibus Plurum: Genomic Analysis Of An Experimentally Evolved Polymorphism In Escherichia Coli, Margie A. Kinnersley, William E. Holben, Frank Rosenzweig

Biological Sciences Faculty Publications

Microbial populations founded by a single clone and propagated under resource limitation can become polymorphic. We sought to elucidate genetic mechanisms whereby a polymorphism evolved in Escherichia coli under glucose limitation and persisted because of cross-feeding among multiple adaptive clones. Apart from a 29 kb deletion in the dominant clone, no large-scale genomic changes distinguished evolved clones from their common ancestor. Using transcriptional profiling on co-evolved clones cultured separately under glucose-limitation we identified 180 genes significantly altered in expression relative to the common ancestor grown under similar conditions. Ninety of these were similarly expressed in all clones, and many of …

Cross-Sectional Dating Of Novel Haplotypes Of Herv-K 113 And Herv-K 115 Indicate These Proviruses Originated In Africa Before Homo Sapiens, Aashish Jha, Satish Pillai, Vanessa York, Elizabeth Sharp, Emily Storm, Douglas Wachter, Jeffrey Martin, Steven Deeks, Michael Rosenberg, Douglas Nixon, Keith Garrison

School of Science Faculty Works

The human genome, human endogenous retroviruses (HERV), of which HERV-K113 and HERV-K115 are the only known full-length proviruses that are insertionally polymorphic. Although a handful of previously published papers have documented their prevalence in the global population; to date, there has been no report on their prevalence in the United States population. Here, we studied the geographic distribution of K113 and K115 among 156 HIV-1+ subjects from the United States, including African Americans, Hispanics, and Caucasians. In the individuals studied, we found higher insertion frequencies of K113 (21%) and K115 (35%) in African Americans compared with Caucasians (K113 9% and …

Circadian Timing Of Food Intake Contributes To Weight Gain, Deanna M. Arble, Joseph Bass, Aaron D. Laposky, Martha H. Vitaterna, Fred W. Turek

Biological Sciences Faculty Research and Publications

Studies of body weight regulation have focused almost entirely on caloric intake and energy expenditure. However, a number of recent studies in animals linking energy regulation and the circadian clock at the molecular, physiological, and behavioral levels raise the possibility that the timing of food intake itself may play a significant role in weight gain. The present study focused on the role of the circadian phase of food consumption in weight gain. We provide evidence that nocturnal mice fed a high‐fat diet only during the 12‐h light phase gain significantly more weight than mice fed only during the 12‐h dark …

Genome 10k: A Proposal To Obtain Whole-Genome Sequence For 10 000 Vertebrate Species, Tony Gamble, Genome 10k Community Of Scientists

Biological Sciences Faculty Research and Publications

The human genome project has been recently complemented by whole-genome assessment sequence of 32 mammals and 24 nonmammalian vertebrate species suitable for comparative genomic analyses. Here we anticipate a precipitous drop in costs and increase in sequencing efficiency, with concomitant development of improved annotation technology and, therefore, propose to create a collection of tissue and DNA specimens for 10 000 vertebrate species specifically designated for whole-genome sequencing in the very near future. For this purpose, we, the Genome 10K Community of Scientists (G₁₀KCOS), will assemble and allocate a biospecimen collection of some 16 203 representative vertebrate species spanning …

Influx Of Calcium Through L-Type Calcium Channels In Early Postnatal Regulation Of Chloride Transporters In The Rat Hippocampus, Jennifer Grace Bray, Michelle Mynlieff

Biological Sciences Faculty Research and Publications

During the early postnatal period, GABA_B receptor activation facilitates L-type calcium current in rat hippocampus. One developmental process that L-type current may regulate is the change in expression of the K⁺Cl⁻ co-transporter (KCC2) and N⁺K⁺2Cl⁻ co-transporter (NKCC1), which are involved in the maturation of the GABAergic system. The present study investigated the connection between L-type current, GABA_B receptors, and expression of chloride transporters during development. The facilitation of L-type current by GABA_B receptors is more prominent in the second week of development, with the highest percentage of cells exhibiting …

Camp Pulsing Of Denuded Mouse Oocytes Increases Meiotic Resumption Via Activation Of Amp-Activated Protein Kinase, Jing Chen, Maggie M. Chi, Kelle H. Moley, Stephen M. Downs

Biological Sciences Faculty Research and Publications

cAMP plays a critical role in the control of oocyte maturation, as a high level of cAMP maintains oocyte arrest at the first meiotic prophase. Yet this study shows that pulsing meiotically arrested denuded oocytes (DO) with cAMP induces oocyte maturation through the activation of AMP-activated protein kinase (PRKA). Short-term (3 h) pulsing of meiotically arrested oocytes with forskolin, an adenyl cyclase (AC) activator, increased oocyte cAMP, led to elevated AMP, and induced oocyte meiotic resumption compared to oocytes continuously cultured in the control medium with or without forskolin. Western analysis showed that germinal vesicle (GV)-stage oocytes after forskolin pulsing …

Characterization Of Arsenic-Tolerant Bacterial Cultures From The Lower Laguna Madre Of South Texas, Gemma A. Berlanga, Michael W. Persans, Thomas Eubanks, Kristine L. Lowe

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Two forms of arsenic are found in the environment: As(V) and As(III), the latter being more toxic, water-soluble, and mobile. Microorganisms may increase the mobility of arsenic by reducing As(V) to As(III); however, detoxification and immobilization can occur via the oxidation of As(III) to As(V). The US EPA has set a minimum contaminant level of 10 parts per billion (ppb) for arsenic in drinking water. The research objective was to confirm the presence of arsenic-tolerant bacteria in the Lower Laguna Madre of south Texas. Sediment samples were collected and inoculated into growth media which contained either 2 mM As(III) or …

Endogenous N-3 Fatty Acids Protect Ovariectomy Induced Bone Loss By Attenuating Osteoclastogenesis, Md Mizanur Rahman, Arunabh Bhattacharya, Jameela Banu, Jing X. Kang, Gabriel Fernandes

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Beneficial effects of n-3 fatty acids (FA) on bone mineral density (BMD) have been reported in mice, rats and human beings, but the precise mechanisms involved have not been described. This study used the Fat-1 mouse, a transgenic model that synthesizes n-3 FA from n-6 FA to directly determine if outcome of bone health were correlated with n-3 FA. Ovariectomized (Ovx) and sham operated wild-type (WT) and Fat-1 mice were fed an AIN-93M diet containing 10% corn oil for 24 weeks. BMD was analysed by dual energy x-ray absorptiometry. Fat-1 Ovx mice exhibited significantly lower level of osteotropic factors like …

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 …

An Intertidal Sea Star Adjusts Thermal Inertia To Avoid Extreme Body Temperatures, Sylvain Pincebourde, Eric Sanford, Brian Helmuth

Faculty Publications

The body temperature of ectotherms is influenced by the interaction of abiotic conditions, morphology, and behavior. Although organisms living in different thermal habitats may exhibit morphological plasticity or move from unfavorable locations, there are few examples of animals adjusting their thermal properties in response to short-term changes in local conditions. Here, we show that the intertidal sea star Pisaster ochraceus modulates its thermal inertia in response to prior thermal exposure. After exposure to high body temperature at low tide, sea stars increase the amount of colder than-air fluid in their coelomic cavity when submerged during high tide, resulting in a …

Poly-Paraphyly Of Hirudinidae: Many Lineages Of Medicinal Leeches, Anna J. Phillips, Mark E. Siddall

Publications and Research

Background: Medicinal leeches became infamous for their utility in bloodletting popularized in the 19th century, and have seen a recent resurgence in post-operative treatments for flap and replantation surgeries, and in terms of characterization of salivary anticoagulants. Notorious throughout the world, the quintessential leech family Hirudinidae has been taken for granted to be monophyletic, as has the non-bloodfeeding family Haemopidae.

Results: This study is the first to evaluate molecular evidence from hirudinid and haemopid leeches in a manner that encompasses the global scope of their taxonomic distributions. We evaluated the presumed monophyly of the Hirudinidae and assessed previous well-accepted classification …