Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 23 of 23

Full-Text Articles in Life Sciences

Intracellular Recording, Sensory Field Mapping, And Culturing Identified Neurons In The Leech, Hirudo Medicinalis, Josh Titlow, Zana R. Majeed, John G. Nicholls, Robin L. Cooper Nov 2013

Intracellular Recording, Sensory Field Mapping, And Culturing Identified Neurons In The Leech, Hirudo Medicinalis, Josh Titlow, Zana R. Majeed, John G. Nicholls, Robin L. Cooper

Biology Faculty Publications

The freshwater leech, Hirudo medicinalis, is a versatile model organism that has been used to address scientific questions in the fields of neurophysiology, neuroethology, and developmental biology. The goal of this report is to consolidate experimental techniques from the leech system into a single article that will be of use to physiologists with expertise in other nervous system preparations, or to biology students with little or no electrophysiology experience. We demonstrate how to dissect the leech for recording intracellularly from identified neural circuits in the ganglion. Next we show how individual cells of known function can be removed from …


Neural Circuit Recording From An Intact Cockroach Nervous System, Josh Titlow, Zana R. Majeed, H. Bernard Hartman, Ellen Burns, Robin L. Cooper Nov 2013

Neural Circuit Recording From An Intact Cockroach Nervous System, Josh Titlow, Zana R. Majeed, H. Bernard Hartman, Ellen Burns, Robin L. Cooper

Biology Faculty Publications

The cockroach ventral nerve cord preparation is a tractable system for neuroethology experiments, neural network modeling, and testing the physiological effects of insecticides. This article describes the scope of cockroach sensory modalities that can be used to assay how an insect nervous system responds to environmental perturbations. Emphasis here is on the escape behavior mediated by cerci to giant fiber transmission in Periplaneta americana. This in situ preparation requires only moderate dissecting skill and electrophysiological expertise to generate reproducible recordings of neuronal activity. Peptides or other chemical reagents can then be applied directly to the nervous system in solution …


Proprioception And Tension Receptors In Crab Limbs: Student Laboratory Exercises, Zana R. Majeed, Josh Titlow, H. Bernard Hartman, Robin L. Cooper Oct 2013

Proprioception And Tension Receptors In Crab Limbs: Student Laboratory Exercises, Zana R. Majeed, Josh Titlow, H. Bernard Hartman, Robin L. Cooper

Biology Faculty Publications

The primary purpose of these procedures is to demonstrate for teaching and research purposes how to record the activity of living primary sensory neurons responsible for proprioception as they are detecting joint position and movement, and muscle tension. Electrical activity from crustacean proprioceptors and tension receptors is recorded by basic neurophysiological instrumentation, and a transducer is used to simultaneously measure force that is generated by stimulating a motor nerve. In addition, we demonstrate how to stain the neurons for a quick assessment of their anatomical arrangement or for permanent fixation. Staining reveals anatomical organization that is representative of chordotonal organs …


Upland Habitat Quality And Historic Landscape Composition Influence Genetic Variation Of A Pond-Breeding Salamander, Stephen C. Richter, Steve J. Price, Chelsea S. Kross, Jeremiah R. Alexander, Michael E. Dorcas Sep 2013

Upland Habitat Quality And Historic Landscape Composition Influence Genetic Variation Of A Pond-Breeding Salamander, Stephen C. Richter, Steve J. Price, Chelsea S. Kross, Jeremiah R. Alexander, Michael E. Dorcas

Forestry and Natural Resources Faculty Publications

Understanding the temporal and spatial scale at which habitat alteration impacts populations is important for conservation and management. Amphibians have declined more than other vertebrates, and pond-breeding species are particularly susceptible to habitat loss and fragmentation because they have terrestrial and aquatic life stages. One approach to management of pond-breeding species is protection of core upland habitat surrounding the breeding pond. We used genetic variation as an indicator of population status in a common amphibian species, spotted salamanders (Ambystoma maculatum), to determine how amount of suitable upland habitat relates to population status in the greater Charlotte, North Carolina, …


Dreadds In Drosophila: A Pharmacogenetic Approach For Controlling Behavior, Neuronal Signaling, And Physiology In The Fly, Jaime Becnel, Oralee Johnson, Zana R Majeed, Vi Tran, Bangning Yu, Bryan L. Roth, Robin L. Cooper, Edmund K. Kerut, Charles D. Nichols Sep 2013

Dreadds In Drosophila: A Pharmacogenetic Approach For Controlling Behavior, Neuronal Signaling, And Physiology In The Fly, Jaime Becnel, Oralee Johnson, Zana R Majeed, Vi Tran, Bangning Yu, Bryan L. Roth, Robin L. Cooper, Edmund K. Kerut, Charles D. Nichols

Biology Faculty Publications

We have translated a powerful genetic tool, designer receptors exclusively activated by designer drugs (DREADDs), from mammalian systems to Drosophila melanogaster to selectively, rapidly, reversibly, and dose-dependently control behaviors and physiological processes in the fly. DREADDs are muscarinic acetylcholine G protein-coupled receptors evolved for loss of affinity to acetylcholine and for the ability to be fully activated by an otherwise biologically inert chemical, clozapine-N-oxide. We demonstrate its ability to control a variety of behaviors and processes in larvae and adults, including heart rate, sensory processing, diurnal behavior, learning and memory, and courtship. The advantages of this particular technology include the …


Pharmacological Analysis Of Dopamine Modulation In The Drosophila Melanogaster Larval Heart, Josh S. Titlow, Jenna M. Rufer, Kayla E. King, Robin L. Cooper Jul 2013

Pharmacological Analysis Of Dopamine Modulation In The Drosophila Melanogaster Larval Heart, Josh S. Titlow, Jenna M. Rufer, Kayla E. King, Robin L. Cooper

Biology Faculty Publications

Dopamine (DA) and other neurotransmitters affect nonneuronal tissues in insects by circulating in the hemolymph. In several organisms, DA has been shown to modulate distinct aspects of cardiac function but the signal transduction pathways that mediate dopaminergic effects on the heart are not well characterized. Here, we used a semiintact Drosophila melanogaster larva preparation and drugs targeting DA receptors and canonical second messenger pathways to identify signaling cascades that mediate the effect of DA on a myogenic heart. DA has a positive chronotropic effect that is mimicked by SKF38393 (type‐1 DA receptor agonist) and quinpirole (type‐2 DA receptor agonist). SCH23390 …


Effect Of Diurnal Fluctuating Versus Constant Temperatures On Germination Of 445 Species From The Eastern Tibet Plateau, Kun Liu, Jerry M. Baskin, Carol C. Baskin, Haiyan Bu, Guozhen Du, Miaojun Ma Jul 2013

Effect Of Diurnal Fluctuating Versus Constant Temperatures On Germination Of 445 Species From The Eastern Tibet Plateau, Kun Liu, Jerry M. Baskin, Carol C. Baskin, Haiyan Bu, Guozhen Du, Miaojun Ma

Biology Faculty Publications

Germination response to fluctuating temperatures is a mechanism by which seeds detect gaps in vegetation canopies and depth of burial in soil, and it is very important for plants. Thus, studies on the effect of fluctuating temperature on germination at the community level are valuable for understanding community structure and biodiversity maintenance. We determined the effects of two alternating temperatures (5/25°C and 10/20°C) and one constant temperature (15°C) on seed germination of 445 species in a grassland community on the eastern Tibet Plateau. Seed mass was determined for each species, and data on habitat, type of life cycle, altitudinal distribution …


Variation In Salamander Tail Regeneration Is Associated With Genetic Factors That Determine Tail Morphology, Gareth J. Voss, D. Kevin Kump, John A. Walker, S. Randal Voss Jul 2013

Variation In Salamander Tail Regeneration Is Associated With Genetic Factors That Determine Tail Morphology, Gareth J. Voss, D. Kevin Kump, John A. Walker, S. Randal Voss

Biology Faculty Publications

Very little is known about the factors that cause variation in regenerative potential within and between species. Here, we used a genetic approach to identify heritable genetic factors that explain variation in tail regenerative outgrowth. A hybrid ambystomatid salamander (Ambystoma mexicanum x A. andersoni) was crossed to an A. mexicanum and 217 offspring were induced to undergo metamorphosis and attain terrestrial adult morphology using thyroid hormone. Following metamorphosis, each salamander’s tail tip was amputated and allowed to regenerate, and then amputated a second time and allowed to regenerate. Also, DNA was isolated from all individuals and genotypes were …


Salamander Hox Clusters Contain Repetitive Dna And Expanded Non-Coding Regions: A Typical Hox Structure For Non-Mammalian Tetrapod Vertebrates?, Stephen Randal Voss, Srikrishna Putta, John A. Walker, Jeramiah J. Smith, Nobuyasu Maki, Panagiotis A. Tsonis Apr 2013

Salamander Hox Clusters Contain Repetitive Dna And Expanded Non-Coding Regions: A Typical Hox Structure For Non-Mammalian Tetrapod Vertebrates?, Stephen Randal Voss, Srikrishna Putta, John A. Walker, Jeramiah J. Smith, Nobuyasu Maki, Panagiotis A. Tsonis

Biology Faculty Publications

Hox genes encode transcription factors that regulate embryonic and post-embryonic developmental processes. The expression of Hox genes is regulated in part by the tight, spatial arrangement of conserved coding and non-coding sequences. The potential for evolutionary changes in Hox cluster structure is thought to be low among vertebrates; however, recent studies of a few non-mammalian taxa suggest greater variation than originally thought. Using next generation sequencing of large genomic fragments (>100 kb) from the red spotted newt (Notophthalamus viridescens), we found that the arrangement of Hox cluster genes was conserved relative to orthologous regions from other vertebrates, but the …


Revisiting The Relationship Between Regenerative Ability And Aging, Ashley W. Seifert, S. Randal Voss Jan 2013

Revisiting The Relationship Between Regenerative Ability And Aging, Ashley W. Seifert, S. Randal Voss

Biology Faculty Publications

Contrary to the longstanding view that newts (Notophthalamus viridescens), but not axolotls (Ambystoma mexicanum), can regenerate a lens, a recent report in BMC Biology by Panagiotis Tsonis and colleagues shows axolotls indeed possess this ability during early larval stages. In contrast, they show that zebrafish never posses this ability, even as embryos. This underscores the importance of comparing regenerative ability across species and reinforces the need to consider organ regeneration in the context of evolution, development, and aging.


The Regulation And Packaging Of Synaptic Vesicles Related To Recruitment Within Crayfish And Fruit Fly Neuromuscular Junctions: Variations In Low- And High-Output Terminals, Wenhui Wu Jan 2013

The Regulation And Packaging Of Synaptic Vesicles Related To Recruitment Within Crayfish And Fruit Fly Neuromuscular Junctions: Variations In Low- And High-Output Terminals, Wenhui Wu

Theses and Dissertations--Biology

Glutamate is the main excitatory neurotransmitter in the CNS and at the neuromuscular junctions (NMJs) of invertebrate. The characteristic similarities to CNS glutamatergic synapses in vertebrate and the anatomical simplicity of invertebrate NMJs favor the investigation of glutamatergic synaptic functions in this system. This dissertation mainly aimed to physiologically separate two functional vesicle groups, the reserve pool (RP) and readily releasable pool (RRP) within presynaptic nerve terminals of Procambarus Clarkii and Drosophila melanogaster. This was addressed in part by blocking the vesicular glutamate transporter (VGlut) with bafilomycin A1. Various frequencies of motor nerve stimulation, exposure time, and concentration of …


Comparison Of Th1 Cytokines And T Cell Markers Gene Expressions Between Virulent And An Attenuated Eiav Vaccine Strain, Talia R. Henkle Jan 2013

Comparison Of Th1 Cytokines And T Cell Markers Gene Expressions Between Virulent And An Attenuated Eiav Vaccine Strain, Talia R. Henkle

Lewis Honors College Capstone Collection

The equine infectious anemia virus (EIAV) is closely related to HIV and has been used as a model to identify protective mechanisms against lentivirus infection. In horses, EIA infection progresses for about a year before infected horses manage to control virus replication. This naturally-gained protection is absolutely dependent on active immune responses as evidenced by the fact that immunosuppressive drugs can induce the recurrence of disease. As the resolution of initial viremia correlates with the appearance of virus specific cytotoxic T lymphocytes (CTL), we believe that cellular immune responses play a key role in controlling EIAV in the horse. In …


Genomics Of A Metamorphic Timing Qtl: Met1 Maps To A Unique Genomic Position And Regulates Morph And Species-Specific Patterns Of Brain Transcription, Robert B. Page, Meredith A. Boley, David K. Kump, Stephen R. Voss Jan 2013

Genomics Of A Metamorphic Timing Qtl: Met1 Maps To A Unique Genomic Position And Regulates Morph And Species-Specific Patterns Of Brain Transcription, Robert B. Page, Meredith A. Boley, David K. Kump, Stephen R. Voss

Biology Faculty Publications

Very little is known about genetic factors that regulate life history transitions during ontogeny. Closely related tiger salamanders (Ambystoma species complex) show extreme variation in metamorphic timing, with some species foregoing metamorphosis altogether, an adaptive trait called paedomorphosis. Previous studies identified a major effect quantitative trait locus (met1) for metamorphic timing and expression of paedomorphosis in hybrid crosses between the biphasic Eastern tiger salamander (Ambystoma tigrinum tigrinum) and the paedomorphic Mexican axolotl (Ambystoma mexicanum). We used existing hybrid mapping panels and a newly created hybrid cross to map the met1 genomic region and …


Equine Serum Antibody Responses To Streptococcus Equi And Streptococcus Zooepidemicus, Rafaela De Negri Jan 2013

Equine Serum Antibody Responses To Streptococcus Equi And Streptococcus Zooepidemicus, Rafaela De Negri

Theses and Dissertations--Veterinary Science

Streptococcus zooepidemicus (Sz) and Streptococcus equi (Se) share 98% DNA sequence homology, but display different pathogenic properties. Infection by one organism does not cross-protect against the other. To better understand pathogenic differences between these organisms and gain information about which proteins are expressed in horses infected experimentally with Se, intrauterine Sz or naturally with respiratory Sz we compared antibody specificities of convalescent sera using ELISA. These comparisons were based on sets of 8 and 14 immunoreactive recombinant proteins of Se strain CF32 and Sz strain NC78, respectively. Sera from donkeys that were previously naturally affected with strangles and later developed …


Axolotl Paedomorphosis: A Comparison Of Juvenile, Metamorphic, And Paedomorphic Ambystoma Mexicanum Brain Gene Transcription, Carlena Johnson Jan 2013

Axolotl Paedomorphosis: A Comparison Of Juvenile, Metamorphic, And Paedomorphic Ambystoma Mexicanum Brain Gene Transcription, Carlena Johnson

Theses and Dissertations--Biology

Unlike many amphibians, the paedomorphic axolotl (Ambystoma mexicanum) rarely undergoes external morphological changes indicative of metamorphosis. However, internally, some axolotl tissues undergo cryptic metamorphic changes. A previous study examined interspecific patterns of larval brain gene expression and found that these species exhibited unique temporal expression patterns that were hypothesized to be morph specific. This thesis tested this hypothesis by examining differences in brain gene expression between juvenile (JUV), paedomorphic (PAED), and metamorphic (MET) axolotls. I identified 828 genes that were expressed differently between JUV, PAED, and MET. Expression estimates from JUV were compared to estimates from PAED and …


Factors Influencing The Establishment And Survival Of Native Hardwood Tree Seedlings Of The Kentucky Inner Bluegrass Blue Ash-Oak Savanna-Woodland, James D. Shaffer Jan 2013

Factors Influencing The Establishment And Survival Of Native Hardwood Tree Seedlings Of The Kentucky Inner Bluegrass Blue Ash-Oak Savanna-Woodland, James D. Shaffer

Theses and Dissertations--Biology

Historically, the Kentucky Inner Bluegrass blue ash-oak savanna-woodland was the primary ecosystem of the Inner Bluegrass Region (IBR) of Kentucky. After European settlement, the majority (>99%) of Bluegrass savanna was converted to agricultural and urban land uses. Currently remnant savanna tree species are failing to recruit. Therefore, a long-term restoration ecology project researching competition and disturbance on seedling establishment, survival, and growth has been established at Griffith Woods (the largest remaining savanna in Kentucky) in Harrison Co., KY. Fourteen native hardwood tree species (a total of 6,168 seedlings) have been experimentally planted. Light, soil, surrounding vegetation, and herbivory, factors …


Comparative Study Of Environmental Factors Influencing Motor Task Learning And Memory Retention In Sighted And Blind Crayfish, Sonya M. Bierbower, Zhanna P. Shuranova, Kert Viele, Robin L. Cooper Jan 2013

Comparative Study Of Environmental Factors Influencing Motor Task Learning And Memory Retention In Sighted And Blind Crayfish, Sonya M. Bierbower, Zhanna P. Shuranova, Kert Viele, Robin L. Cooper

Biology Faculty Publications

In classical conditioning, an alteration in response occurs when two stimuli are regularly paired in close succession. An area of particular research interest is classical conditioning with a chemical signal and visual and/or tactile stimuli as the unconditional stimuli, to test manipulative and motor behaviors in a learning paradigm. A classical learning task chamber was developed to examine learning trends in a sighted surface-dwelling crayfish, Procambarus clarkii, and in a blind cave-dwelling crayfish, Orconectes australis packardi. We examined whether learning is influenced by environmental factors and/or reliance on different primary sensory modalities. Crayfish were trained to manipulate a large, cumbersome …


Physical Dormancy In Seeds, With Special Reference To Geraniaceae: Morpho-Anatomy, Development, Physiology, Biomechanics And Classification Of Water-Gap Complexes, Nalin Suranjith Gama Arachchige Jan 2013

Physical Dormancy In Seeds, With Special Reference To Geraniaceae: Morpho-Anatomy, Development, Physiology, Biomechanics And Classification Of Water-Gap Complexes, Nalin Suranjith Gama Arachchige

Theses and Dissertations--Biology

The primary aims of this dissertation were to (1) identify and characterize the water-gap complex in seeds of Geraniaceae, (2) investigate its role in physical dormancy (PY) break and (3) develop a new classification system for water-gap complexes in seeds of angiosperms. The winter annuals Geranium carolinianum and G. dissectum were selected as the main representative species for the study, and seeds of an additional 29 species from the Geraniaceae were used to compare the water-gap complex within the family. A new classification system for water-gap complexes in species with PY was developed by comparing the morpho-anatomical features of PY …


The Contribution Of Two Related Bbp-Binding Gyf Proteins, Smy2 And Syh1, To Cellular Rna Abundance And Genome Stability, Min Chen Jan 2013

The Contribution Of Two Related Bbp-Binding Gyf Proteins, Smy2 And Syh1, To Cellular Rna Abundance And Genome Stability, Min Chen

Theses and Dissertations--Biology

Nuclear precursor of mature messenger RNA (pre-mRNA) splicing is one of the most highly regulated processes in eukaryotic organisms. In addition to its role in the removal of constitutive or alternative introns present in the pre-mRNA, splicing is also highly integrated into other layers of gene expression. This study investigates the potential role of the nuclear branchpoint binding protein (BBP) outside of the pre-mRNA splicing cycle. More specifically, we were interested in the biological relevance of its association with two cytoplasmic proteins Smy2 and Syh1. Smy2 and Syh1 belong to the GYF family of poly-proline binding proteins, and their roles …


Investigation Of Media Ingredients And Water Sources For Algae Co2 Capture At Different Scales To Demonstrate The Correlations Between Lab-Scale And Large-Scale Growth, Tabitha Graham Jan 2013

Investigation Of Media Ingredients And Water Sources For Algae Co2 Capture At Different Scales To Demonstrate The Correlations Between Lab-Scale And Large-Scale Growth, Tabitha Graham

Theses and Dissertations--Biosystems and Agricultural Engineering

As energy use increases globally the environmental burdens increase alike. Many accusations have been made that carbon dioxide is a culprit of climate change. The University of Kentucky and Duke Energy Power have partnered to test carbon capture technology in a large scale project. To this end, the objective of this thesis is to investigate potential water media sources and nutrient sources at different volume scales for algae cultivation to help create a more environmentally viable and economically feasible solution. This work will conduct a life cycle assessment of water media sources and the effects of the inputs and outputs …


Characterization Of G-Patch Motif Contribution To Prp43 Function In The Pre-Messenger Rna Splicing And Ribosomal Rna Biogenesis Pathways, Daipayan Banerjee Jan 2013

Characterization Of G-Patch Motif Contribution To Prp43 Function In The Pre-Messenger Rna Splicing And Ribosomal Rna Biogenesis Pathways, Daipayan Banerjee

Theses and Dissertations--Biology

The DExD/H-box protein Prp43 is essential for two biological processes: nucleoplasmic pre-mRNA splicing and nucleolar rRNA maturation. The biological basis for the temporal and spatial regulation of Prp43 remains elusive. The Spp382/Ntr1, Sqs1/Pfa1 and Pxr1/Gno1 G-patch proteins bind to and activate the Prp43 DExD/H box-helicase in pre-mRNA splicing (Spp382) and rRNA processing (Sqs1, Pxr1). These Prp43-interacting proteins each contain the G-patch domain, a conserved sequence of ~48 amino acids that includes 6 highly conserved glycine (G) residues. Five annotated G-patch proteins in baker’s yeast (i.e., Spp382, Pxr1, Spp2, Sqs1 and Ylr271) and with the possible exception of the uncharacterized Ylr271 …


Towards Elucidation Of A Viral Dna Packaging Motor, Chad T. Schwartz Jan 2013

Towards Elucidation Of A Viral Dna Packaging Motor, Chad T. Schwartz

Theses and Dissertations--Pharmacy

Previously, gp16, the ATPase protein of phi29 DNA packaging motor, was an enigma due to its tendency to form multiple oligomeric states. Recently we employed new methodologies to decipher both its stoichiometry and also the mechanism in which the protein functions to hydrolyze ATP and provide the driving force for DNA packaging. The oligomeric states were determined by biochemical and biophysical approaches. Contrary to many reported intriguing models of viral DNA packaging, it was found that phi29 DNA packaging motor permits the translocation of DNA unidirectionally and driven cooperatively by three rings of defined shape. The mechanism for the generation …


Effects Of Streamside Management Zone Timber Harvest On Salamander Communities In Robinson Forest, Thomas Maigret Jan 2013

Effects Of Streamside Management Zone Timber Harvest On Salamander Communities In Robinson Forest, Thomas Maigret

Theses and Dissertations--Forestry and Natural Resources

Salamanders are critical components of forest ecosystems, in terms of total biomass, as well as for their value as indicators of ecosystem stress. Considering the worldwide decline in amphibian populations, the known effects of timber harvest on salamander populations, and the importance of the forest products industry in Kentucky and elsewhere, the impacts of silvicultural operations on salamander communities cannot be overlooked. The objective was to investigate the effects of three different silvicultural treatments, each involving different streamside management zone (SMZ) characteristics, on salamander communities in ephemeral streams. Data were collected by regular checks of pitfall traps, coverboards, and transect …