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Biology

University of Massachusetts Amherst

Selected Works

Articles 1 - 30 of 151

Full-Text Articles in Life Sciences

Systematic Screen Of Chemotherapeutics In Drosophila Stem Cell Tumors, Michele Markstein, Samantha Detorree, Julio Cho, Ralph Neumüller, Soren Craig-Müller, Norbert Perrimon Jan 2014

Systematic Screen Of Chemotherapeutics In Drosophila Stem Cell Tumors, Michele Markstein, Samantha Detorree, Julio Cho, Ralph Neumüller, Soren Craig-Müller, Norbert Perrimon

Michele Markstein

Here we report the development of an in vivo system to study the interaction of stem cells with drugs using a tumor model in the adult Drosophila intestine. Strikingly, we find that some Food and Drug Administration-approved chemotherapeutics that can inhibit the growth of Drosophila tumor stem cells can paradoxically promote the hyperproliferation of their wild-type counterparts. These results reveal an unanticipated side effect on stem cells that may contribute to tumor recurrence. We propose that the same side effect may occur in humans based on our finding that it is driven in Drosophila by the evolutionarily conserved Janus kinase-signal …


Science And Policy On Endocrine Disrupters Must Not Be Mixed: A Reply To A "Common Sense" Intervention By Toxicology Journal Editors, Åke Bergman, Anna-Maria Andersson, Georg Becher, Martin Van Den Berg, Bruce Blumberg, Poul Bjerregaard, Carl-Gustaf Bornehag, Riana Bornman, Ingvar Brandt, Jayne V. Brian, Stephanie C. Casey, Paul A. Fowler, Heloise Frouin, Linda C. Giudice, Taisen Iguchi, Ulla Hass, Susan Jobling, Anders Juul, Karen A. Kidd, Andreas Kortenkamp, Monica Lind, Olwenn V. Martin, Derek Muir, Roseline Ochieng, Nicolas Olea, Leif Norrgren, Erik Ropstad, Peter S. Ross, Christina Rudén, Martin Scheringer, Niels Erik Skakkebaek, Olle Söder, Carlos Sonnenschein, Ana Soto, Shanna Swan, Jorma Toppari, Charles R. Tyler, Laura N. Vandenberg, Anne Marie Vinggaard, Karin Wiberg, R. Thomas Zoeller Aug 2013

Science And Policy On Endocrine Disrupters Must Not Be Mixed: A Reply To A "Common Sense" Intervention By Toxicology Journal Editors, Åke Bergman, Anna-Maria Andersson, Georg Becher, Martin Van Den Berg, Bruce Blumberg, Poul Bjerregaard, Carl-Gustaf Bornehag, Riana Bornman, Ingvar Brandt, Jayne V. Brian, Stephanie C. Casey, Paul A. Fowler, Heloise Frouin, Linda C. Giudice, Taisen Iguchi, Ulla Hass, Susan Jobling, Anders Juul, Karen A. Kidd, Andreas Kortenkamp, Monica Lind, Olwenn V. Martin, Derek Muir, Roseline Ochieng, Nicolas Olea, Leif Norrgren, Erik Ropstad, Peter S. Ross, Christina Rudén, Martin Scheringer, Niels Erik Skakkebaek, Olle Söder, Carlos Sonnenschein, Ana Soto, Shanna Swan, Jorma Toppari, Charles R. Tyler, Laura N. Vandenberg, Anne Marie Vinggaard, Karin Wiberg, R. Thomas Zoeller

R. Thomas Zoeller

The “common sense” intervention by toxicology journal editors regarding proposed European Union endocrine disrupter regulations ignores scientific evidence and well-established principles of chemical risk assessment. In this commentary, endocrine disrupter experts express their concerns about a recently published, and is in our considered opinion inaccurate and factually incorrect, editorial that has appeared in several journals in toxicology. Some of the shortcomings of the editorial are discussed in detail. We call for a better founded scientific debate which may help to overcome a polarisation of views detrimental to reaching a consensus about scientific foundations for endocrine disrupter regulation in the EU.


Perturbation Of Brachypodium Distachyon Cellulose Synthase A4 Or 7 Results In Abnormal Cell Walls, Pubudu P. Handakumbura, Dominick A. Matos, Karen S. Osmont, Michael J. Harrington, Kyuyoung Heo, Kabindra Kafle, Seong H. Kim, Tobias Baskin, Samuel P. Hazen Jan 2013

Perturbation Of Brachypodium Distachyon Cellulose Synthase A4 Or 7 Results In Abnormal Cell Walls, Pubudu P. Handakumbura, Dominick A. Matos, Karen S. Osmont, Michael J. Harrington, Kyuyoung Heo, Kabindra Kafle, Seong H. Kim, Tobias Baskin, Samuel P. Hazen

Tobias Baskin

Background: Cellulose is an integral component of the plant cell wall and accounts for approximately forty percent of total plant biomass but understanding its mechanism of synthesis remains elusive. CELLULOSE SYNTHASE A (CESA) proteins function as catalytic subunits of a rosette-shaped complex that synthesizes cellulose at the plasma membrane. Arabidopsis thaliana and rice (Oryza sativa) secondary wall CESA loss-of-function mutants have weak stems and irregular or thin cell walls. Results: Here, we identify candidates for secondary wall CESAs in Brachypodium distachyon as having similar amino acid sequence and expression to those characterized in A. thaliana, namely CESA4/7/8. To functionally characterize …


Perturbation Of Brachypodium Distachyon Cellulose Synthase A4 Or 7 Results In Abnormal Cell Walls, Pubudu P. Handakumbura, Dominick A. Matos, Karen S. Osmont, Michael J. Harrington, Kyuyoung Heo, Kabindra Kafle, Seong H. Kim, Tobias I. Baskin, Samuel P. Hazen Jan 2013

Perturbation Of Brachypodium Distachyon Cellulose Synthase A4 Or 7 Results In Abnormal Cell Walls, Pubudu P. Handakumbura, Dominick A. Matos, Karen S. Osmont, Michael J. Harrington, Kyuyoung Heo, Kabindra Kafle, Seong H. Kim, Tobias I. Baskin, Samuel P. Hazen

Samuel P Hazen

Background: Cellulose is an integral component of the plant cell wall and accounts for approximately forty percent of total plant biomass but understanding its mechanism of synthesis remains elusive. CELLULOSE SYNTHASE A (CESA) proteins function as catalytic subunits of a rosette-shaped complex that synthesizes cellulose at the plasma membrane. Arabidopsis thaliana and rice (Oryza sativa) secondary wall CESA loss-of-function mutants have weak stems and irregular or thin cell walls. Results: Here, we identify candidates for secondary wall CESAs in Brachypodium distachyon as having similar amino acid sequence and expression to those characterized in A. thaliana, namely CESA4/7/8. To functionally characterize …


My Relations With Russian Polymer Science, Otto Vogl, Frank T. Traceski, Friderikh Diachekovski Jan 2013

My Relations With Russian Polymer Science, Otto Vogl, Frank T. Traceski, Friderikh Diachekovski

Otto Vogl

No abstract provided.


Functional Characterization Of Cinnamyl Alcohol Dehydrogenase And Caffeic Acid O-Methyltransferase In Brachypodium Distachyon, Gina M. Trabucco, Dominick A. Matos, Scott J. Lee, Aaron J. Saathoff, Henry D. Priest, Todd C. Mockler, Gautam Sarath, Samuel P. Hazen Jan 2013

Functional Characterization Of Cinnamyl Alcohol Dehydrogenase And Caffeic Acid O-Methyltransferase In Brachypodium Distachyon, Gina M. Trabucco, Dominick A. Matos, Scott J. Lee, Aaron J. Saathoff, Henry D. Priest, Todd C. Mockler, Gautam Sarath, Samuel P. Hazen

Samuel P Hazen

Background: Lignin is a significant barrier in the conversion of plant biomass to bioethanol. Cinnamyl alcohol dehydrogenase (CAD) and caffeic acid O-methyltransferase (COMT) catalyze key steps in the pathway of lignin monomer biosynthesis. Brown midrib mutants in Zea mays and Sorghum bicolor with impaired CAD or COMT activity have attracted considerable agronomic interest for their altered lignin composition and improved digestibility. Here, we identified and functionally characterized candidate genes encoding CAD and COMT enzymes in the grass model species Brachypodium distachyon with the aim of improving crops for efficient biofuel production. Results: We developed transgenic plants overexpressing artificial microRNA designed …


Crystallization And Polymerization, Otto Vogl, Frank T. Traceski, Eric G. Vogl Oct 2012

Crystallization And Polymerization, Otto Vogl, Frank T. Traceski, Eric G. Vogl

Otto Vogl

No abstract provided.


Pictures From My Life With Polymer Science: Album 12, Otto Vogl Sep 2012

Pictures From My Life With Polymer Science: Album 12, Otto Vogl

Otto Vogl

No abstract provided.


Solid State Chemical Reactions And Polymerizations: The Initial Synthesis Of Dna?, Otto Vogl, Frank T. Traceski Jun 2012

Solid State Chemical Reactions And Polymerizations: The Initial Synthesis Of Dna?, Otto Vogl, Frank T. Traceski

Otto Vogl

A Proposal for Covering individual Macromolecules with Macromolecules including a Realistic Chiral Synthesis of Nucleic Acids.


Does The Precision Of A Biological Clock Depend Upon Its Period? Effects Of The Duper And Tau Mutations In Syrian Hamsters, Eric L. Bittman May 2012

Does The Precision Of A Biological Clock Depend Upon Its Period? Effects Of The Duper And Tau Mutations In Syrian Hamsters, Eric L. Bittman

Eric L. Bittman

Mutations which alter the feedback loops that generate circadian rhythms may provide insight into their insensitivity to perturbation robustness) and their consistency of period (precision). I examined relationships between endogenous period, activity and rest (τDD, α and ρ) in Syrian hamsters using two different mutations, duper and tau, both of which speed up the circadian clock. I generated 8 strains of hamsters that are homozygous or heterozygous for the tau, duper, and wild type alleles in all combinations. The endogenous period of activity onsets among these strains ranged from 17.94+0.04 to 24.13±0.04 h. Contrary to predictions, the variability of period …


Macondo Crude Oil From The Deepwater Horizon Oil Spill Disrupts Specific Developmental Processes During Zebrafish Embryogenesis, T Yvanka De Soysa, Allison Ulrich, Timo Friedrich, Danielle Pite, Shannon L. Compton, Deborah Ok, Rebecca L. Bernardos, Gerald B. Downes, Shizuka Hsieh, Rachael Stein, M Caterina Lagdameo, Katherine Halvorsen, Lydia-Rose Kesich, Michael Jf Barresi May 2012

Macondo Crude Oil From The Deepwater Horizon Oil Spill Disrupts Specific Developmental Processes During Zebrafish Embryogenesis, T Yvanka De Soysa, Allison Ulrich, Timo Friedrich, Danielle Pite, Shannon L. Compton, Deborah Ok, Rebecca L. Bernardos, Gerald B. Downes, Shizuka Hsieh, Rachael Stein, M Caterina Lagdameo, Katherine Halvorsen, Lydia-Rose Kesich, Michael Jf Barresi

Gerald B. Downes

Background: The Deepwater Horizon disaster was the largest marine oil spill in history, and total vertical exposure of oil to the water column suggests it could impact an enormous diversity of ecosystems. The most vulnerable organisms are those encountering these pollutants during their early life stages. Water-soluble components of crude oil and specific polycyclic aromatic hydrocarbons have been shown to cause defects in cardiovascular and craniofacial development in a variety of teleost species, but the developmental origins of these defects have yet to be determined. We have adopted zebrafish, Danio rerio, as a model to test whether water accumulated fractions …


Identification And Expression Analysis Of Methyl Jasmonate Responsive Ests In Paclitaxel Producing Taxus Cuspidata Suspension Culture Cells, Sangram K. Lenka, Nadia Boutaoui, Bibin Paulose, Kham Vongpaseuth, Jennifer Normanly, Susan C. Roberts, Elsbeth L. Walker Apr 2012

Identification And Expression Analysis Of Methyl Jasmonate Responsive Ests In Paclitaxel Producing Taxus Cuspidata Suspension Culture Cells, Sangram K. Lenka, Nadia Boutaoui, Bibin Paulose, Kham Vongpaseuth, Jennifer Normanly, Susan C. Roberts, Elsbeth L. Walker

Elsbeth Walker

Background Taxol(R)(paclitaxel) promotes microtubule assembly and stabilization and therefore is a potent chemotherapeutic agent against wide range of cancers. Methyl jasmonate (MJ) elicited Taxus cell cultures provide a sustainable option to meet the growing market demand for paclitaxel. Despite its increasing pharmaceutical importance, the molecular genetics of paclitaxel biosynthesis is not fully elucidated. This study focuses on identification of MJ responsive transcripts in cultured Taxus cells using PCR-based suppression subtractive hybridization (SSH) to identify genes involved in global pathway control. Results Six separate SSH cDNA libraries of paclitaxel-accumulating Taxus cuspidata P991 cell lines were constructed at three different post-elicitation time …


Transcriptional Regulation Of Grass Secondary Cell Wall Biosynthesis: Playing Catch-Up With Arabidopsis Thaliana, Pubudu P. Handakumbura, Samuel P. Hazen Apr 2012

Transcriptional Regulation Of Grass Secondary Cell Wall Biosynthesis: Playing Catch-Up With Arabidopsis Thaliana, Pubudu P. Handakumbura, Samuel P. Hazen

Samuel P Hazen

Secondary cell wall synthesis occurs in specialized cell types following completion of cell enlargement. By virtue of mechanical strength provided by a wall thickened with cellulose, hemicelluloses, and lignin, these cells can function as water-conducting vessels and provide structural support. Several transcription factor families regulate genes encoding wall synthesis enzymes. Certain NAC and MYB proteins directly bind to the SNBE and AC elements upstream of structural genes and other transcription factors. The most detailed model of this regulatory network is established predominantly for a eudicot, Arabidopsis thaliana. In grasses, both the patterning and the composition of secondary cell walls are …


Mutation Of Zebrafish Dihydrolipoamide Branched-Chain Transacylase E2 Results In Motor Dysfunction And Models Maple Syrup Urine Disease, Timo Friedrich, Aaron M. Lambert, Mark A. Masino, Gerald B. Downes Mar 2012

Mutation Of Zebrafish Dihydrolipoamide Branched-Chain Transacylase E2 Results In Motor Dysfunction And Models Maple Syrup Urine Disease, Timo Friedrich, Aaron M. Lambert, Mark A. Masino, Gerald B. Downes

Gerald B. Downes

Analysis of zebrafish mutants that demonstrate abnormal locomotive behavior can elucidate the molecular requirements for neural network function and provide new models of human disease. Here, we show that zebrafish quetschkommode (que) mutant larvae exhibit a progressive locomotor defect that culminates in unusual nose-to-tail compressions and an inability to swim. Correspondingly, extracellular peripheral nerve recordings show that que mutants demonstrate abnormal locomotor output to the axial muscles used for swimming. Using positional cloning and candidate gene analysis, we reveal that a point mutation disrupts the gene encoding dihydrolipoamide branched-chain transacylase E2 (Dbt), a component of a mitochondrial enzyme complex, to …


Biological Conversion Assay Using Clostridium Phytofermentans To Estimate Plant Feedstock Quality, Scott J. Lee, Thomas A. Warnick, Sivakumar Pattahil, Jesus G. Alvelo-Maurosa, Michelle J. Serapiglia, Heather Mccormick, Virginia Brown, Naomi F. Young, Danny J. Schnell, Lawrence B. Smart, Michael G. Hahn, Jeffrey F. Pedersen, Susan B. Leschine, Samuel P. Hazen Feb 2012

Biological Conversion Assay Using Clostridium Phytofermentans To Estimate Plant Feedstock Quality, Scott J. Lee, Thomas A. Warnick, Sivakumar Pattahil, Jesus G. Alvelo-Maurosa, Michelle J. Serapiglia, Heather Mccormick, Virginia Brown, Naomi F. Young, Danny J. Schnell, Lawrence B. Smart, Michael G. Hahn, Jeffrey F. Pedersen, Susan B. Leschine, Samuel P. Hazen

Samuel P Hazen

Background - There is currently considerable interest in developing renewable sources of energy. One strategy is the biological conversion of plant biomass to liquid transportation fuel. Several technical hurdles impinge upon the economic feasibility of this strategy, including the development of energy crops amenable to facile deconstruction. Reliable assays to characterize feedstock quality are needed to measure the effects of pre-treatment and processing and of the plant and microbial genetic diversity that influence bioconversion efficiency. Results - We used the anaerobic bacterium Clostridium phytofermentans to develop a robust assay for biomass digestibility and conversion to biofuels. The assay utilizes the …


Pictures From My Life With Polymer Science: Album 11, Otto Vogl Feb 2012

Pictures From My Life With Polymer Science: Album 11, Otto Vogl

Otto Vogl

No abstract provided.


Chirality And Handedness, Otto Vogl, Frank T. Traceski Jan 2012

Chirality And Handedness, Otto Vogl, Frank T. Traceski

Otto Vogl

No abstract provided.


How Pearls Are Made: A New Perspective, Otto Vogl Jan 2012

How Pearls Are Made: A New Perspective, Otto Vogl

Otto Vogl

No abstract provided.


Degradadation, Aging And Stabilization, Otto Vogl Jan 2012

Degradadation, Aging And Stabilization, Otto Vogl

Otto Vogl

No abstract provided.


From The Congress In Vienna (Metternich) To The Pacific Polymer Federation, Otto Vogl, Frank T. Traceski Jan 2012

From The Congress In Vienna (Metternich) To The Pacific Polymer Federation, Otto Vogl, Frank T. Traceski

Otto Vogl

No abstract provided.


Brachypodium As A Model For The Grasses: Today And The Future, Jelena Brkljacic, Erich Grotewold, Randy Scholl, Todd Mockler, David F. Garvin, Philippe Vain, Thomas Brutnell, Richard Sibout, Michael Bevan, Hikmet Budak, Ana L. Caicedo, Caixia Gao, Yong Gu, Samuel P. Hazen, Ben F. Holt Iii, Shin-Young Hong, Antonio J. Manzaneda, Thomas Mitchell-Olds, Keiichi Mochida, Luis A. J. Mur, Chung-Mo Park, John Sedbrook, Michelle Watt, Shao Jian Zheng, John P. Vogel Sep 2011

Brachypodium As A Model For The Grasses: Today And The Future, Jelena Brkljacic, Erich Grotewold, Randy Scholl, Todd Mockler, David F. Garvin, Philippe Vain, Thomas Brutnell, Richard Sibout, Michael Bevan, Hikmet Budak, Ana L. Caicedo, Caixia Gao, Yong Gu, Samuel P. Hazen, Ben F. Holt Iii, Shin-Young Hong, Antonio J. Manzaneda, Thomas Mitchell-Olds, Keiichi Mochida, Luis A. J. Mur, Chung-Mo Park, John Sedbrook, Michelle Watt, Shao Jian Zheng, John P. Vogel

Samuel P Hazen

No abstract provided.


Expression Of Human Amyloid Precursor Protein In The Skeletal Muscles Of Drosophila Results In Age- And Activity-Dependent Muscle Weakness, Lawrence M. Schwartz, Chul Kim, Sapeckshita Srivastava, Marian Rice, Tanja A. Godenschwege, Brooke Bentley, Saranya Ravi, Shuang Shao, Ig T. Woodard Apr 2011

Expression Of Human Amyloid Precursor Protein In The Skeletal Muscles Of Drosophila Results In Age- And Activity-Dependent Muscle Weakness, Lawrence M. Schwartz, Chul Kim, Sapeckshita Srivastava, Marian Rice, Tanja A. Godenschwege, Brooke Bentley, Saranya Ravi, Shuang Shao, Ig T. Woodard

Lawrence M. Schwartz

Background One of the hallmarks of Alzheimer's disease, and several other degenerative disorders such as Inclusion Body Myositis, is the abnormal accumulation of amyloid precursor protein (APP) and its proteolytic amyloid peptides. To better understand the pathological consequences of inappropriate APP expression on developing tissues, we generated transgenic flies that express wild-type human APP in the skeletal muscles, and then performed anatomical, electrophysiological, and behavioral analysis of the adults. Results We observed that neither muscle development nor animal longevity was compromised in these transgenic animals. However, human APP expressing adults developed age-dependent defects in both climbing and flying. We could …


Regulation Of Solute Flux Through Plasmodesmata In The Root Meristem, Heidi L. Rutschow, Tobias Baskin, Eric M. Kramer Feb 2011

Regulation Of Solute Flux Through Plasmodesmata In The Root Meristem, Heidi L. Rutschow, Tobias Baskin, Eric M. Kramer

Tobias Baskin

Plasmodesmata permit solutes to move between cells nonspecifically and without having to cross a membrane. This symplastic connectivity, while straightforward to observe using fluorescent tracers, has proven difficult to quantify. We use fluorescence recovery after photobleaching, combined with a mathematical model of symplastic diffusion, to assay plasmodesmata-mediated permeability in the Arabidopsis (Arabidopsis thaliana) root meristem in wild-type and transgenic lines, and under selected chemical treatments. The permeability measured for the wild type is nearly 10-times greater than previously reported. Plamodesmal permeability remains constant in seedlings treated with auxin (30 nm indoleacetic acid for 2 and 24 h; 100 nm indoleacetic …


Asymmetry In Chemical Structures And In Life: My Last Two Articles, Otto Vogl Jan 2011

Asymmetry In Chemical Structures And In Life: My Last Two Articles, Otto Vogl

Otto Vogl

No abstract provided.


Center Of Umass – Industry Research On Polymers: Cumirp: Inception And Founding, Otto Vogl Jan 2011

Center Of Umass – Industry Research On Polymers: Cumirp: Inception And Founding, Otto Vogl

Otto Vogl

No abstract provided.


Polymer Science And The Arts: Oriental Lacquer, Otto Vogl Jan 2011

Polymer Science And The Arts: Oriental Lacquer, Otto Vogl

Otto Vogl

No abstract provided.


Brachypodium As A Model For The Grasses: Today And The Future, Ana Lucia Caicedo, J. Brkljacic, E. Grotewold, R. Scholl, T. Mocker, D. F. Garvin, P. Vain, T. Brutnell, R. Sibout, M. Bevan, H. Budak, C. Gao, Y. Gu, S. P. Hazen, B. F. Holt Iii, S. -Y Hong, M. Jordan, A. J. Manzaneda, T. Michell-Olds, K. Mochida, L. A.J. Mur, C. -M. Park, J. Sedbrook, M. Watt, S. J. Zheng, J. P. Vogel Jan 2011

Brachypodium As A Model For The Grasses: Today And The Future, Ana Lucia Caicedo, J. Brkljacic, E. Grotewold, R. Scholl, T. Mocker, D. F. Garvin, P. Vain, T. Brutnell, R. Sibout, M. Bevan, H. Budak, C. Gao, Y. Gu, S. P. Hazen, B. F. Holt Iii, S. -Y Hong, M. Jordan, A. J. Manzaneda, T. Michell-Olds, K. Mochida, L. A.J. Mur, C. -M. Park, J. Sedbrook, M. Watt, S. J. Zheng, J. P. Vogel

Ana Lucia Caicedo

No abstract provided.


Molecular Evolution Of The Rice Blast Resistance Gene Pi-Ta In Invasive Weedy Rice In The Usa, Ana Lucia Caicedo, S. Lee, Y. Jia, D. R. Gealy, K. M. Olsen Jan 2011

Molecular Evolution Of The Rice Blast Resistance Gene Pi-Ta In Invasive Weedy Rice In The Usa, Ana Lucia Caicedo, S. Lee, Y. Jia, D. R. Gealy, K. M. Olsen

Ana Lucia Caicedo

The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and …


Timing Is Everything: Early Degradation Of Abscission Layer Is Associated With Increased Seed Shattering In U.S. Weedy Rice, Ana Lucia Caicedo, C. S. Thurber, P. K. Helper Jan 2011

Timing Is Everything: Early Degradation Of Abscission Layer Is Associated With Increased Seed Shattering In U.S. Weedy Rice, Ana Lucia Caicedo, C. S. Thurber, P. K. Helper

Ana Lucia Caicedo

Background Seed shattering, or shedding, is an important fitness trait for wild and weedy grasses. U.S. weedy rice (Oryza sativa) is a highly shattering weed, thought to have evolved from non-shattering cultivated ancestors. All U.S. weedy rice individuals examined to date contain a mutation in the sh4 locus associated with loss of shattering during rice domestication. Weedy individuals also share the shattering trait with wild rice, but not the ancestral shattering mutation at sh4; thus, how weedy rice reacquired the shattering phenotype is unknown. To establish the morphological basis of the parallel evolution of seed shattering in weedy rice and …


Brother Of Cdo (Umleitung) Is Cell-Autonomously Required For Hedgehog-Mediated Ventral Cns Patterning In The Zebrafish, Sadie A. Bergeron, Oksana V. Tyurina, Emily Miller, Andrea Bagas, Rolf O. Karlstrom Jan 2011

Brother Of Cdo (Umleitung) Is Cell-Autonomously Required For Hedgehog-Mediated Ventral Cns Patterning In The Zebrafish, Sadie A. Bergeron, Oksana V. Tyurina, Emily Miller, Andrea Bagas, Rolf O. Karlstrom

Rolf O Karlstrom

The transmembrane protein Brother of Cdo (Boc) has been implicated in Shh-mediated commissural axon guidance, and can both positively and negatively regulate Hedgehog (Hh) target gene transcription, however, little is known about in vivo requirements for Boc during vertebrate embryogenesis. The zebrafish umleitung (umlty54) mutant was identified by defects in retinotectal axon projections. Here, we show that the uml locus encodes Boc and that Boc function is cell-autonomously required for Hh-mediated neural patterning. Our phenotypic analysis suggests that Boc is required as a positive regulator of Hh signaling in the spinal cord, hypothalamus, pituitary, somites and upper jaw, but that …