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Full-Text Articles in Life Sciences

Positional Plasticity In Regenerating Amybstoma Mexicanum Limbs Is Associated With Cell Proliferation And Pathways Of Cellular Differentiation, Catherine D. Mccusker, Antony Athippozhy, Carlos Diaz-Castillo, Charless Fowlkes, David M. Gardiner, S. Randal Voss Nov 2015

Positional Plasticity In Regenerating Amybstoma Mexicanum Limbs Is Associated With Cell Proliferation And Pathways Of Cellular Differentiation, Catherine D. Mccusker, Antony Athippozhy, Carlos Diaz-Castillo, Charless Fowlkes, David M. Gardiner, S. Randal Voss

Biology Faculty Publications

BACKGROUND: The endogenous ability to dedifferentiate, re-pattern, and re-differentiate adult cells to repair or replace damaged or missing structures is exclusive to only a few tetrapod species. The Mexican axolotl is one example of these species, having the capacity to regenerate multiple adult structures including their limbs by generating a group of progenitor cells, known as the blastema, which acquire pattern and differentiate into the missing tissues. The formation of a limb regenerate is dependent on cells in the connective tissues that retain memory of their original position in the limb, and use this information to generate the pattern …


Initial Characterization Of The Large Genome Of The Salamander Ambystoma Mexicanum Using Shotgun And Laser Capture Chromosome Sequencing, Melissa C. Keinath, Vladimir A. Timoshevskiy, Nataliya Y. Timoshevskaya, Panagiotis A. Tsonis, S. Randal Voss, Jeramiah J. Smith Nov 2015

Initial Characterization Of The Large Genome Of The Salamander Ambystoma Mexicanum Using Shotgun And Laser Capture Chromosome Sequencing, Melissa C. Keinath, Vladimir A. Timoshevskiy, Nataliya Y. Timoshevskaya, Panagiotis A. Tsonis, S. Randal Voss, Jeramiah J. Smith

Biology Faculty Publications

Vertebrates exhibit substantial diversity in genome size, and some of the largest genomes exist in species that uniquely inform diverse areas of basic and biomedical research. For example, the salamander Ambystoma mexicanum (the Mexican axolotl) is a model organism for studies of regeneration, development and genome evolution, yet its genome is ~10× larger than the human genome. As part of a hierarchical approach toward improving genome resources for the species, we generated 600 Gb of shotgun sequence data and developed methods for sequencing individual laser-captured chromosomes. Based on these data, we estimate that the A. mexicanum genome is ~32 Gb. …


Seed Germination Ecology Of The Cold Desert Annual Isatis Violascens (Brassicaceae): Two Levels Of Physiological Dormancy And Role Of The Pericarp, Yuan M. Zhou, Juan J. Lu, Dun Y. Tan, Carol C. Baskin, Jerry M. Baskin Oct 2015

Seed Germination Ecology Of The Cold Desert Annual Isatis Violascens (Brassicaceae): Two Levels Of Physiological Dormancy And Role Of The Pericarp, Yuan M. Zhou, Juan J. Lu, Dun Y. Tan, Carol C. Baskin, Jerry M. Baskin

Biology Faculty Publications

The occurrence of various species of Brassicaceae with indehiscent fruits in the cold deserts of NW China suggests that there are adaptive advantages of this trait. We hypothesized that the pericarp of the single-seeded silicles of Isatis violascens restricts embryo expansion and thus prevents germination for 1 or more years. Thus, our aim was to investigate the role of the pericarp in seed dormancy and germination of this species. The effects of afterripening, treatment with gibberellic acid (GA3) and cold stratification on seed dormancy-break were tested using intact silicles and isolated seeds, and germination phenology was monitored in …


Disruption Of Daily Rhythms By High-Fat Diet Is Reversible, Katrina L. Branecky, Kevin D. Niswender, Julie S. Pendergast Sep 2015

Disruption Of Daily Rhythms By High-Fat Diet Is Reversible, Katrina L. Branecky, Kevin D. Niswender, Julie S. Pendergast

Biology Faculty Publications

In mammals a network of circadian clocks coordinates behavior and physiology with 24-h environmental cycles. Consumption of high-fat diet disrupts this temporal coordination by advancing the phase of the liver molecular clock and altering daily rhythms of eating behavior and locomotor activity. In this study we sought to determine whether these effects of high-fat diet on circadian rhythms were reversible. We chronically fed mice high-fat diet and then returned them to low-fat chow diet. We found that the phase of the liver PERIOD2::LUCIFERASE rhythm was advanced (by 4h) and the daily rhythms of eating behavior and locomotor activity were altered …


Maintenance Of Brucellosis In Yellowstone Bison: Linking Seasonal Food Resources, Host-Pathogen Interaction, And Life-History Trade-Offs, John J. Treanor, Chris Geremia, Michael A. Ballou, Duane H. Keisler, Patrick J. White, John J. Cox, Phillip H. Crowley Sep 2015

Maintenance Of Brucellosis In Yellowstone Bison: Linking Seasonal Food Resources, Host-Pathogen Interaction, And Life-History Trade-Offs, John J. Treanor, Chris Geremia, Michael A. Ballou, Duane H. Keisler, Patrick J. White, John J. Cox, Phillip H. Crowley

Biology Faculty Publications

The seasonal availability of food resources is an important factor shaping the life-history strategies of organisms. During times of nutritional restriction, physiological trade-offs can induce periods of immune suppression, thereby increasing susceptibility to infectious disease. Our goal was to provide a conceptual framework describing how the endemic level bovine brucellosis (Brucella abortus) may be maintained in Yellowstone bison based on the seasonality of food resources and the life-history strategies of the host and pathogen. Our analysis was based on active B. abortus infection (measured via bacterial culture), nutritional indicators (measured as metabolites and hormones in plasma), and carcass …


Kidney-Specific Reduction Of Oxidative Phosphorylation Genes Derived From Spontaneously Hypertensive Rat, Jason A. Collett, Jiffin K. Paulose, Vincent M. Cassone, Jeffrey L. Osborn Aug 2015

Kidney-Specific Reduction Of Oxidative Phosphorylation Genes Derived From Spontaneously Hypertensive Rat, Jason A. Collett, Jiffin K. Paulose, Vincent M. Cassone, Jeffrey L. Osborn

Biology Faculty Publications

Mitochondrial (Mt) dysfunction contributes to the pathophysiology of renal function and promotes cardiovascular disease such as hypertension. We hypothesize that renal Mt-genes derived from female spontaneously hypertensive rats (SHR) that exhibit hypertension have reduced expression specific to kidney cortex. After breeding a female Okamoto-Aoki SHR (SAP = 188mmHg) with Brown Norway (BN) males (SAP = 100 and 104 mmHg), hypertensive female progeny were backcrossed with founder BN for 5 consecutive generations in order to maintain the SHR mitochondrial genome in offspring that contain over increasing BN nuclear genome. Mt-protein coding genes (13 total) and nuclear transcription factors mediating Mt-gene transcription …


The Sea Lamprey Meiotic Map Improves Resolution Of Ancient Vertebrate Genome Duplications, Jeramiah James Smith, Melissa C. Keinath Aug 2015

The Sea Lamprey Meiotic Map Improves Resolution Of Ancient Vertebrate Genome Duplications, Jeramiah James Smith, Melissa C. Keinath

Biology Faculty Publications

It is generally accepted that many genes present in vertebrate genomes owe their origin to two whole-genome duplications that occurred deep in the ancestry of the vertebrate lineage. However, details regarding the timing and outcome of these duplications are not well resolved. We present high-density meiotic and comparative genomic maps for the sea lamprey (Petromyzon marinus), a representative of an ancient lineage that diverged from all other vertebrates ~550 million years ago. Linkage analyses yielded a total of 95 linkage groups, similar to the estimated number of germline chromosomes (1n ~ 99), spanning a total of 5570.25 cM. …


Distribution Of Three Congeneric Shrub Species Along An Aridity Gradient Is Related To Seed Germination And Seedling Emergence, Liming Lai, Yuan Tian, Yongji Wang, Xuechun Zhao, Lianhe Jiang, Jerry M. Baskin, Carol C. Baskin, Yuanrun Zheng Jul 2015

Distribution Of Three Congeneric Shrub Species Along An Aridity Gradient Is Related To Seed Germination And Seedling Emergence, Liming Lai, Yuan Tian, Yongji Wang, Xuechun Zhao, Lianhe Jiang, Jerry M. Baskin, Carol C. Baskin, Yuanrun Zheng

Biology Faculty Publications

Environmental tolerance of a species has been shown to correlate positively with its geographical range. On the Ordos Plateau, three Caragana species are distributed sequentially along the precipitation gradient. We hypothesized that this geographical distribution pattern is related to environmental tolerances of the three Caragana species during seed germination and seedling emergence stages. To test this hypothesis, we examined seed germination under different temperature, light and water potentials, and monitored seedling emergence for seeds buried at eight sand depths and given different amounts of water. Seeds of C. korshinskii germinated to high percentages at 5 : 15 to 25 : …


Gene Expression During The First 28 Days Of Axolotl Limb Regeneration I: Experimental Design And Global Analysis Of Gene Expression, S. Randal Voss, Alex Palumbo, Radha Nagarajan, David M. Gardiner, Ken Muneoka, Arnold J. Stromberg, Antony T. Athippozhy Jun 2015

Gene Expression During The First 28 Days Of Axolotl Limb Regeneration I: Experimental Design And Global Analysis Of Gene Expression, S. Randal Voss, Alex Palumbo, Radha Nagarajan, David M. Gardiner, Ken Muneoka, Arnold J. Stromberg, Antony T. Athippozhy

Biology Faculty Publications

While it is appreciated that global gene expression analyses can provide novel insights about complex biological processes, experiments are generally insufficiently powered to achieve this goal. Here we report the results of a robust microarray experiment of axolotl forelimb regeneration. At each of 20 post-amputation time points, we estimated gene expression for 10 replicate RNA samples that were isolated from 1 mm of heterogeneous tissue collected from the distal limb tip. We show that the limb transcription program diverges progressively with time from the non-injured state, and divergence among time adjacent samples is mostly gradual. However, punctuated episodes of transcription …


Tissue Specific Reactions To Positional Discontinuities In The Regenerating Axolotl Limb, Malcolm Maden, Daima Avila, Molly Roy, Ashley W. Seifert Jun 2015

Tissue Specific Reactions To Positional Discontinuities In The Regenerating Axolotl Limb, Malcolm Maden, Daima Avila, Molly Roy, Ashley W. Seifert

Biology Faculty Publications

We investigated cellular contributions to intercalary regenerates and 180o supernumerary limbs during axolotl limb regeneration using the cell autonomous green fluorescent protein marker and exchanged blastemas between white and green fluorescent protein animals. After distal blastemas were grafted to proximal levels tissues of the intercalary regenerate behaved independently with regard to the law of distal transformation; graft epidermis was replaced by stump epidermis, muscle-derived cells, blood vessels, and Schwann cells of the distal blastema moved proximally to the stylopodium and cartilage and dermal cells conformed to the law. After 180o rotation, blastemas showed contributions from stump tissues which …