Life Sciences Commons^™

Arabidopsis Trithorax1 Dynamically Regulates Flowering Locus C Activation Via Histone 3 Lysine 4 Trimethylation, Stephane Pien, Delphine Fleury, Joshua S. Mylne, Pedro Crevillen, Dirk Inze, Zoya Avramova, Caroline Dean, Ueli Grossniklaus

School of Biological Sciences: Faculty Publications

Trithorax function is essential for epigenetic maintenance of gene expression in animals, but little is known about trithorax homologs in plants. ARABIDOPSIS TRITHORAX1 (ATX1) was shown to be required for the expression of homeotic genes involved in flower organogenesis. Here, we report a novel function of ATX1, namely, the epigenetic regulation of the floral repressor FLOWERING LOCUS C (FLC). Downregulation of FLC accelerates the transition from vegetative to reproductive development in Arabidopsis thaliana. In the atx1 mutant, FLC levels are reduced and the FLC chromatin is depleted of trimethylated, but not dimethylated, histone 3 lysine 4, suggesting a specific …

The Genome Sequence Of The Metal-Mobilizing, Extremely Thermoacidophilic Archaeon Metallosphaera Sedula Provides Insights Into Bioleaching-Associated Metabolism, Kathryne S. Auernik, Yukari Maezato, Paul H. Blum, Robert M. Kelly

School of Biological Sciences: Faculty Publications

Despite their taxonomic description, not all members of the order Sulfolobales are capable of oxidizing

reduced sulfur species, which, in addition to iron oxidation, is a desirable trait of biomining microorganisms.

However, the complete genome sequence of the extremely thermoacidophilic archaeon Metallosphaera sedula

DSM 5348 (2.2 Mb, _2,300 open reading frames [ORFs]) provides insights into biologically catalyzed metal

sulfide oxidation. Comparative genomics was used to identify pathways and proteins involved (directly or

indirectly) with bioleaching. As expected, the M. sedula genome contains genes related to autotrophic carbon

fixation, metal tolerance, and adhesion. Also, terminal oxidase cluster organization indicates the presence …

Evaluation Of Aerial Cluster Sampling Of Double-Crested Cormorants On Aquaculture Ponds In Mississippi, Brian S. Dorr, Loren W. Burger Jr., Scott C. Barras

USDA Wildlife Services: Staff Publications

Concern over increasing numbers of double-crested cormorants (Phalacrocorax auritus) and their impacts on channel catfish (Ictalurus punctatus) aquaculture has resulted in increased need for quantitative information to develop and evaluate depredation management efforts. We evaluated aerial surveys in a stratified cluster sampling (SCS) design to estimate and monitor abundance of cormorants on catfish aquaculture ponds in the Yazoo River Basin of Mississippi, USA (hereafter Yazoo Basin). Twice monthly abundance estimates and coefficient of variation during winter averaged 8,128 (n = 29, SE = 1,233) and 33% (n = 29, SE = 0.02), respectively. Counts of cormorants …

Sustainability In A Time Of Climate Change: Developing An Intensive Research Framework For The Platte River Basin And The High Plains Proceedings From The 2008 Climate Change Workshop, Monica Norby, Ashley Washburn

Office of Research and Economic Development: Publications

Proceedings from the 2008 Climate change Workshop, Nebraska Sandhills, May 19-22, 2008. Hosted by the University of Nebraska–Lincoln and the U.S. Geological Survey

Ecological Genomics: Understanding Gene And Genome Function In The Natural Environment, M. C. Ungerer, L. C. Johnson, M. A. Herman

School of Biological Sciences: Faculty Publications

The field of ecological genomics seeks to understand the genetic mechanisms underlying responses of organisms to their natural environments. This is being achieved through the application of functional genomic approaches to identify and characterize genes with ecological and evolutionary relevance. By its very nature, ecological genomics is an interdisciplinary field. In this review, we consider the significance of this new area of study from both an ecological and genomic perspective using examples from the recent literature. We submit that by considering more fully an ecological context, researchers may gain additional insights into the underlying genetic basis of ecologically relevant phenotypic …

The Spectrum Of Mitochondrial Mutation Differs Across Species, Kristi L. Montooth, David M. Rand

School of Biological Sciences: Faculty Publications

Mutations are ubiquitous, and many arise during the very process of replicating and transmitting genomes. This process is the source of the genetic variation that provides the raw material for both evolutionary novelty and human disease. Mutation rates are known to vary among nucleotides, across genomic regions, and between taxa. It is conventional wisdom that animal mitochondrial DNA (mtDNA) is one genomic region that has a particularly high mutation rate. Until recently, this high rate of mutation has been predominantly inferred from high levels of mitochondrial sequence divergence between species. However, the apparently simple process of mutation and sequence divergence …

Analysis Of Wnt Signaling During Caenorhabditis Elegans Postembryonic Development, Samantha Van Hoffelen, Michael A. Herman

School of Biological Sciences: Faculty Publications

Wnts play a central role in the development of many cells and tissue types in all species studied to date. Like many other extracellular signaling pathways, secreted Wnt proteins are involved in many different processes; in C. elegans these include cell proliferation, differentiation, cell migration, control of cell polarity, axon outgrowth, and control of the stem cell niche. Perturbations in Wnt signaling are also key factors in cancer formation, and therefore of interest to oncobiologists. Wnts are secreted glycoproteins, which bind to Frizzled transmembrane receptors and signal either through, or independently of β-catenin. Both β-catenin-dependent (Wnt/β-catenin) and -independent pathways function …

Endogenous And Exogenous Control Of Ecosystem Function: N Cycling In Headwater Streams, H. M. Valett, S. A. Thomas, P. J. Mulholland, J. R. Webster, C. N. Dahm, C. S. Fellows, C. L. Crenshaw, C. G. Peterson

School of Biological Sciences: Faculty Publications

Allochthonous inputs act as resource subsidies to many ecosystems, where they exert strong influences on metabolism and material cycling. At the same time, metabolic theory proposes endogenous thermal control independent of resource supply. To address the relative importance of exogenous and endogenous influences, we quantified spatial and temporal variation in ecosystem metabolism and nitrogen (N) uptake using seasonal releases of ¹⁵N as nitrate in six streams differing in riparian–stream interaction and metabolic character. Nitrate removal was quantified using a nutrient spiraling approach based on measurements of downstream decline in ¹⁵N flux. Respiration (R) and gross primary production (GPP) …