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

Digital Commons Network

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

Articles 1 - 17 of 17

Full-Text Articles in Entire DC Network

Frigida Like 2 Is A Functional Allele In Landsberg Erecta And Compensates For A Nonsense Allele Of Frigida Like 1, Michael Schläppi Dec 2006

Frigida Like 2 Is A Functional Allele In Landsberg Erecta And Compensates For A Nonsense Allele Of Frigida Like 1, Michael Schläppi

Biological Sciences Faculty Research and Publications

The Landsberg erecta (Ler) accession of Arabidopsis (Arabidopsis thaliana) has a weak allele of the floral inhibitor FLOWERING LOCUS C (FLC). FLC-Ler is weakly up-regulated by the active San Feliu-2 (Sf2) allele of FRIGIDA (FRI-Sf2), resulting in a moderately late-flowering phenotype. By contrast, the Columbia (Col) allele of FLC is strongly up-regulated by FRI-Sf2, resulting in a very late-flowering phenotype. In Col, the FRI-related gene FRI LIKE 1 (FRL1) is required for FRI-mediated upregulation of FLC. It is shown here that in Ler …


The Distribution Of Lianas And Their Change In Abundance In Temperate Forests Over The Past 45 Years, Ronald A. Londre, Stefan A. Schnitzer Dec 2006

The Distribution Of Lianas And Their Change In Abundance In Temperate Forests Over The Past 45 Years, Ronald A. Londre, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

Lianas (woody vines) are an important and dynamic component of many forests throughout the world, and increases in CO2, mean winter temperature, and forest fragmentation may promote their growth and proliferation in temperate forests. In this study, we used a 45‐year data set to test the hypothesis that lianas have increased in abundance and basal area in the interiors of 14 deciduous temperate forests in Wisconsin (USA) since 1959. We also censused woody plants along a gradient from the forest edge to the interior in seven of these forests to test the hypothesis that the abundance of lianas …


Spinobulbar Neurons In Lamprey: Cellular Properties And Synaptic Interactions, James F. Einum, James T. Buchanan Oct 2006

Spinobulbar Neurons In Lamprey: Cellular Properties And Synaptic Interactions, James F. Einum, James T. Buchanan

Biological Sciences Faculty Research and Publications

An in vitro preparation of the nervous system of the lamprey, a lower vertebrate, was used to characterize the properties of spinal neurons with axons projecting to the brain stem [i.e., spinobulbar (SB) neurons)]. To identify SB neurons, extracellular electrodes on each side of the spinal cord near the obex recorded the axonal spikes of neurons impaled with sharp intracellular microelectrodes in the rostral spinal cord. The ascending spinal neurons (n = 144) included those with ipsilateral (iSB) (63/144), contralateral (cSB) (77/144), or bilateral (bSB) (4/144) axonal projections to the brain stem. Intracellular injection of biocytin revealed that the …


Low Cell Ph Depresses Peak Power In Rat Skeletal Muscle Fibres At Both 30°C And 15°C: Implications For Muscle Fatigue, Shannon T. Knuth, H. Dave, Jim R. Peters, Robert Fitts Sep 2006

Low Cell Ph Depresses Peak Power In Rat Skeletal Muscle Fibres At Both 30°C And 15°C: Implications For Muscle Fatigue, Shannon T. Knuth, H. Dave, Jim R. Peters, Robert Fitts

Biological Sciences Faculty Research and Publications

Historically, an increase in intracellular H+ (decrease in cell pH) was thought to contribute to muscle fatigue by direct inhibition of the cross-bridge leading to a reduction in velocity and force. More recently, due to the observation that the effects were less at temperatures closer to those observed in vivo, the importance of H+ as a fatigue agent has been questioned. The purpose of this work was to re-evaluate the role of H+ in muscle fatigue by studying the effect of low pH (6.2) on force, velocity and peak power in rat fast-and slow-twitch muscle fibres …


Censusing And Measuring Lianas: A Quantitative Comparison Of The Common Methods, Stefan A. Schnitzer, Saara J. Dewalt, Jérôme Chave Sep 2006

Censusing And Measuring Lianas: A Quantitative Comparison Of The Common Methods, Stefan A. Schnitzer, Saara J. Dewalt, Jérôme Chave

Biological Sciences Faculty Research and Publications

Lianas contribute to many aspects of tropical forest diversity and dynamics, and interest in liana ecology has grown substantially in recent years. Methods to census lianas and estimate biomass, however, differ among studies, possibly hindering attempts to compare liana communities. At Nouragues Research Station (French Guiana), we tested the extent to which liana abundance, basal area, and estimated biomass differed depending on stem diameter measurement location, inclusion of ramets, inclusion of lianas rooted within versus passing through the plot, and plot shape. We found that the mean per plot abundance and basal area of lianas were significantly greater when lianas …


Macronuclear Genome Sequence Of The Ciliate Tetrahymena Thermophila, A Model Eukaryote, Jonathan A. Eisen, Robert S. Coyne, Martin Wu, Dongying Wu, Mathangi Thiagarajan, Jennifer R. Wortman, Jonathan H. Badger, Qinghu Ren, Paolo Amedeo, Kristie M. Jones, Luke J. Tallon, Arthur L. Delcher, Steven L. Salzberg, Joana C. Silva, Brian J. Haas, William H. Majoros, Maryam Farzad, Jane M. Carlton, Roger K. Smith, Jyoti Garg, Ronald E. Pearlman, Kathleen M. Karrer, Lei Sun, Gerard Manning, Nels C. Elde, Aaron P. Turkewitz, David J. Asai, David E. Wilkes, Yufeng Wang, Hong Cai, Kathleen Collins, B. Andrew Stewart, Suzanne R. Lee, Katarzyna Wilamowska, Zasha Weinberg, Walter L. Ruzzo, Dorota Wloga, Jacek Gaertig, Joseph Frankel, Che-Chia Tsao, Martin A. Gorovsky, Patrick J. Keeling, Ross F. Waller, Nicola J. Patron, J. Michael Cherry, Nicholas A. Stover, Cynthia J. Krieger, Christina Del Toro, Hilary F. Ryder, Sondra C. Williamson, Rebecca A. Barbeau, Eileen P. Hamilton, Eduardo Orias Sep 2006

Macronuclear Genome Sequence Of The Ciliate Tetrahymena Thermophila, A Model Eukaryote, Jonathan A. Eisen, Robert S. Coyne, Martin Wu, Dongying Wu, Mathangi Thiagarajan, Jennifer R. Wortman, Jonathan H. Badger, Qinghu Ren, Paolo Amedeo, Kristie M. Jones, Luke J. Tallon, Arthur L. Delcher, Steven L. Salzberg, Joana C. Silva, Brian J. Haas, William H. Majoros, Maryam Farzad, Jane M. Carlton, Roger K. Smith, Jyoti Garg, Ronald E. Pearlman, Kathleen M. Karrer, Lei Sun, Gerard Manning, Nels C. Elde, Aaron P. Turkewitz, David J. Asai, David E. Wilkes, Yufeng Wang, Hong Cai, Kathleen Collins, B. Andrew Stewart, Suzanne R. Lee, Katarzyna Wilamowska, Zasha Weinberg, Walter L. Ruzzo, Dorota Wloga, Jacek Gaertig, Joseph Frankel, Che-Chia Tsao, Martin A. Gorovsky, Patrick J. Keeling, Ross F. Waller, Nicola J. Patron, J. Michael Cherry, Nicholas A. Stover, Cynthia J. Krieger, Christina Del Toro, Hilary F. Ryder, Sondra C. Williamson, Rebecca A. Barbeau, Eileen P. Hamilton, Eduardo Orias

Biological Sciences Faculty Research and Publications

The ciliate Tetrahymena thermophila is a model organism for molecular and cellular biology. Like other ciliates, this species has separate germline and soma functions that are embodied by distinct nuclei within a single cell. The germline-like micronucleus (MIC) has its genome held in reserve for sexual reproduction. The soma-like macronucleus (MAC), which possesses a genome processed from that of the MIC, is the center of gene expression and does not directly contribute DNA to sexual progeny. We report here the shotgun sequencing, assembly, and analysis of the MAC genome of T. thermophila, which is approximately 104 Mb in length and …


Characterization Of Mmp37p, A Saccharomyces Cerevisiae Mitochondrial Matrix Protein With A Role In Mitochondrial Protein Import, Michelle R. Gallas, Mary Kathryn Dienhart, Rosemary A. Stuart, Roy M. Long Sep 2006

Characterization Of Mmp37p, A Saccharomyces Cerevisiae Mitochondrial Matrix Protein With A Role In Mitochondrial Protein Import, Michelle R. Gallas, Mary Kathryn Dienhart, Rosemary A. Stuart, Roy M. Long

Biological Sciences Faculty Research and Publications

Many mitochondrial proteins are encoded by nuclear genes and after translation in the cytoplasm are imported via translocases in the outer and inner membranes, the TOM and TIM complexes, respectively. Here, we report the characterization of the mitochondrial protein, Mmp37p (YGR046w) and demonstrate its involvement in the process of protein import into mitochondria. Haploid cells deleted of MMP37 are viable but display a temperature-sensitive growth phenotype and are inviable in the absence of mitochondrial DNA. Mmp37p is located in the mitochondrial matrix where it is peripherally associated with the inner membrane. We show that Mmp37p has a role in the …


Progeny Of Germ Line Knockouts Of Asi2, A Gene Encoding A Putative Signal Transduction Receptor In Tetrahymena Thermophila, Fail To Make The Transition From Sexual Reproduction To Vegetative Growth, Shuqiang Li, Lihui Yin, Eric S. Cole, Rupa A. Udani, Kathleen M. Karrer Jul 2006

Progeny Of Germ Line Knockouts Of Asi2, A Gene Encoding A Putative Signal Transduction Receptor In Tetrahymena Thermophila, Fail To Make The Transition From Sexual Reproduction To Vegetative Growth, Shuqiang Li, Lihui Yin, Eric S. Cole, Rupa A. Udani, Kathleen M. Karrer

Biological Sciences Faculty Research and Publications

The ciliated protozoan Tetrahymena has two nuclei: a germ line micronucleus and a somatic macronucleus. The transcriptionally active macronucleus has about 50 copies of each chromosome. At sexual reproduction (conjugation), the parental macronucleus is degraded and new macronucleus develops from a mitotic product of the zygotic micronucleus. Development of the macronucleus involves massive genome remodeling, including deletion of about 6000 specific internal eliminated sequences (IES) and multiple rounds of DNA replication. A gene encoding a putative signal transduction receptor, ASI2, (anlagen stage induced 2) is up-regulated during development of the new macronuclei (anlagen). Macronuclear ASI2 is nonessential for vegetative …


Tumor Suppressor Activity Of Odc Antizyme In Mek-Driven Skin Tumorigenesis, David J. Feith, Sofia Origanti, Paula L. Shoop, Suzanne Sass-Kuhn, Lisa M. Shantz May 2006

Tumor Suppressor Activity Of Odc Antizyme In Mek-Driven Skin Tumorigenesis, David J. Feith, Sofia Origanti, Paula L. Shoop, Suzanne Sass-Kuhn, Lisa M. Shantz

Biological Sciences Faculty Research and Publications

To test the hypothesis that suppression of ornithine decarboxylase (ODC) activity blocks the promotion of target cells in the outer root sheath of the hair follicle initiated by Raf/MEK/ERK activation, we crossed mice overexpressing an activated MEK mutant in the skin (K14-MEK mice) with two transgenic lines overexpressing antizyme (AZ), which binds to ODC and targets it for degradation. K14-MEK mice develop spontaneous skin tumors without initiation or promotion. These mice on the ICR background were crossed with K5-AZ and K6-AZ mice on both the carcinogenesis-resistant C57BL/6 background and the sensitive DBA/2 background. Expression of AZ driven by either the …


Ampk Regulation Of Mouse Oocyte Meiotic Resumption In Vitro, Jing Chen, Emma R. Hudson, Maggie M. Chi, Aimee S. Chang, Kelle H. Moley, D. Grahame Hardie, Stephen M. Downs Mar 2006

Ampk Regulation Of Mouse Oocyte Meiotic Resumption In Vitro, Jing Chen, Emma R. Hudson, Maggie M. Chi, Aimee S. Chang, Kelle H. Moley, D. Grahame Hardie, Stephen M. Downs

Biological Sciences Faculty Research and Publications

We have previously shown that the adenosine analog 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR), an activator of AMP-activated protein kinase (AMPK), stimulates an increase in AMPK activity and induces meiotic resumption in mouse oocytes [Downs, S.M., Hudson, E.R., Hardie, D.G., 2002. A potential role for AMP-activated protein kinase in meiotic induction in mouse oocytes. Dev. Biol, 245, 200–212]. The present study was carried out to better define a causative role for AMPK in oocyte meiotic maturation. When microinjected with a constitutively active AMPK, about 20% of mouse oocytes maintained in meiotic arrest with dibutyryl cAMP (dbcAMP) were stimulated to undergo germinal vesicle breakdown (GVB), …


Predicting Liana Crown Location From Stem Diameter In Three Panamanian Lowland Forests, Brian P. Kurzel, Stefan A. Schnitzer, Walter P. Carson Mar 2006

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 Mar 2006

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.


Nuclear Rna Surveillance In Saccharomyces Cerevisiae: Trf4p-Dependent Polyadenylation Of Nascent Hypomethylated Trna And An Aberrant Form Of 5s Rrna, Sujatha A. Kadaba, Xuying Wang, James T. Anderson Mar 2006

Nuclear Rna Surveillance In Saccharomyces Cerevisiae: Trf4p-Dependent Polyadenylation Of Nascent Hypomethylated Trna And An Aberrant Form Of 5s Rrna, Sujatha A. Kadaba, Xuying Wang, James T. Anderson

Biological Sciences Faculty Research and Publications

1-Methyladenosine modification at position 58 of tRNA is catalyzed by a two-subunit methyltransferase composed of Trm6p and Trm61p in Saccharomyces cerevisiae. Initiator tRNA (tRNAiMet) lacking m1A58 (hypomethylated) is rendered unstable through the cooperative function of the poly(A) polymerases, Trf4p/Trf5p, and the nuclear exosome. We provide evidence that a catalytically active Trf4p poly(A) polymerase is required for polyadenylation of hypomethylated tRNAiMet in vivo. DNA sequence analysis of tRNAiMet cDNAs and Northern hybridizations of poly(A)+ RNA provide evidence that nascent pre-tRNAiMet transcripts are targeted for polyadenylation and degradation. We determined …


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 Mar 2006

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 …


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 Feb 2006

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 …


An Engineered Nonsense Ura3 Allele Provides A Versatile System To Detect The Presence, Absence And Appearance Of The [Em>Psi+] Prion In Saccharomyces Cerevisiae, Anita L. Manogaran, Kathryn T. Kirkland, Susan W. Liebman Jan 2006

An Engineered Nonsense Ura3 Allele Provides A Versatile System To Detect The Presence, Absence And Appearance Of The [Em>Psi+] Prion In Saccharomyces Cerevisiae, Anita L. Manogaran, Kathryn T. Kirkland, Susan W. Liebman

Biological Sciences Faculty Research and Publications

Common methods to identify yeast cells containing the prion form of the Sup35 translation termination factor, [PSI+], involve a nonsense suppressor phenotype. Decreased function of Sup35p in [PSI+] cells leads to readthrough of certain nonsense mutations in a few auxotrophic markers, for example, ade1-14. This readthrough results in growth on adenine deficient media. While this powerful tool has dramatically facilitated the study of [PSI+], it is limited to a narrow range of laboratory strains and cannot easily be used to screen for cells that have lost the [PSI+ …


The Flagellar Motility Of Chlamydomonas Pf25 Mutant Lacking An Akap-Binding Protein Is Overtly Sensitive To Medium Conditions, Chun Yang, Pinfen Yang Jan 2006

The Flagellar Motility Of Chlamydomonas Pf25 Mutant Lacking An Akap-Binding Protein Is Overtly Sensitive To Medium Conditions, Chun Yang, Pinfen Yang

Biological Sciences Faculty Research and Publications

Radial spokes are a conserved axonemal structural complex postulated to regulate the motility of 9 + 2 cilia and flagella via a network of phosphoenzymes and regulatory proteins. Consistently, a Chlamydomonas radial spoke protein, RSP3, has been identified by RII overlays as an A-kinase anchoring protein (AKAP) that localizes the cAMP-dependent protein kinase (PKA) holoenzyme by binding to the RIIa domain of PKA RII subunit. However, the highly conserved docking domain of PKA is also found in the N termini of several AKAP-binding proteins unrelated to PKA as well as a 24-kDa novel spoke protein, RSP11. Here, we report that …