Bio-Med Roundup

This month in Bio-Med Roundup:
    • Fraser et al. analyzed the initial dynamics of the swine flu outbreak.
    • Elsaesser et al., Yi et al., and Fröhlich et al. showed that interleukin-21, a cytokine produce by CD4+ T cells, helps control chronic viral infection in mice.
    • Dioum et al. found that a deacetylase implicated in aging directly regulates a transcription factor that controls stress-responsive genes.
    • Moustafa et al. found that diatom genomes contain remnants of both green and red algal genomes, hinting at a complex evolutionary past.
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MEDICINE
 
Rhes, a Striatal Specific Protein, Mediates Mutant-Huntingtin Cytotoxicity (5 June 2009)
S. Subramaniam et al.
A small G protein localized in the brain striatum may explain the localized neurodegeneration observed in Huntington’s disease.

Hyper-Recombination, Diversity, and Antibiotic Resistance in Pneumococcus (12 June 2009)
W. P. Hanage et al.
Promiscuity not only leads to diversity in streptococcal bacteria, but also to an increased likelihood of acquiring drug resistance.

Inhibition of Hedgehog Signaling Enhances Delivery of Chemotherapy in a Mouse Model of Pancreatic Cancer (12 June 2009)
K. P. Olive et al.
Pancreatic tumors are unresponsive to chemotherapy because their limited vasculature precludes efficient drug delivery.
See related Perspective.

Pandemic Potential of a Strain of Influenza A (H1N1): Early Findings (19 June 2009)
C. Fraser et al.
An international collaborative effort has analyzed the initial dynamics of the swine flu outbreak. 

MicroRNA-92a Controls Angiogenesis and Functional Recovery of Ischemic Tissues in Mice (26 June 2009)
A. Bonauer et al.
Inhibition of a microRNA that represses blood vessel growth enhances the recovery of tissue damaged by an inadequate blood supply. 

Mitochondrial STAT3 Supports Ras-Dependent Oncogenic Transformation (26 June 2009)
D. J. Gough et al.
A transcription factor promotes the transformation of cells by the Ras oncogene only when present in the mitochondrion.
 

MOLECULAR BIOLOGY

Epigenetic Temporal Control of Mouse Hox Genes in Vivo (5 June 2009)
N. Soshnikova and D. Duboule
A time-dependent transition in chromatin modifications parallels the sequential activation of genes involved in embryo organization. 

McsB Is a Protein Arginine Kinase That Phosphorylates and Inhibits the Heat-Shock Regulator CtsR (5 June 2009)
J. Fuhrmann et al.
A protein kinase can specifically target arginine residues in a transcription factor to regulate its DNA binding. 

Extensive Demethylation of Repetitive Elements During Seed Development Underlies Gene Imprinting (12 June 2009)
M. Gehring et al.
Gene function in Arabidopsis endosperm depends on whether a gene is maternally or paternally inherited. 

Genome-Wide Demethylation of Arabidopsis Endosperm (12 June 2009)
T.-F. Hsieh et al.
The endosperm genome of Arabidopsis shows extensive gene imprinting. 

Synthetic Heterochromatin Bypasses RNAi and Centromeric Repeats to Establish Functional Centromeres (26 June 2009)
A. Kagansky et al.
A tethered methyltransferase induces the tight-packing of DNA, the formation of a kinetochore, and chromosome segregation. 

Diversity and Complexity in DNA Recognition by Transcription Factors (26 June 2009)
G. Badis et al.
A broad survey of transcription factors reveals that related proteins can have multiple and differing DNA binding specificities. 


NEUROSCIENCE/PSYCHOLOGY

Did Warfare Among Ancestral Hunter-Gatherers Affect the Evolution of Human Social Behaviors? (5 June 2009)
S. Bowles
Prehistoric conflict among humans could have favored the survival of groups containing altruists.
See related Perspective.

Fluorescent False Neurotransmitters Visualize Dopamine Release from Individual Presynaptic Terminals (12 June 2009)
N. G. Gubernator et al.
Optical tracking of neurotransmitter release in the brain reveals multiple synaptic populations that depend on brain activity. 

Synapse- and Stimulus-Specific Local Translation During Long-Term Neuronal Plasticity (19 June 2009)
D. O. Wang et al.
Live-cell microscopy reveals local translation during long-term facilitation of Aplysia sensory-motor synapses.
See related Perspective.

Merkel Cells Are Essential for Light-Touch Responses (19 June 2009)
S. M. Maricich et al.
In the skin, special cells with specific properties endow their afferent nerves with the ability to resolve fine spatial details. 

Recruitment of an Area Involved in Eye Movements During Mental Arithmetic (19 June 2009)
A. Knops et al.
Addition and subtraction are encoded in the same part of the brain that is responsible for eye movements and spatial attention. 

Ventral Tegmental Area BDNF Induces an Opiate-Dependent–Like Reward State in Naïve Rats (26 June 2009)
H. Vargas-Perez et al.
A growth factor involved in neuronal plasticity alters neurons in a specific area of the brain after chronic exposure to opioid drugs.


IMMUNOLOGY

Halofuginone Inhibits TH17 Cell Differentiation by Activating the Amino Acid Starvation Response (5 June 2009)
M. S. Sundrud et al.
Activation of the amino acid starvation response inhibits differentiation of a subset of inflammatory T cells.
See related Perspective.

IL-21 Is Required to Control Chronic Viral Infection (19 June 2009)
H. Elsaesser et al.
Interleukin-21 produced by CD4+ T cells helps CD8+ T cells control viral infection in a mouse model.
See related Perspective.

A Vital Role for Interleukin-21 in the Control of a Chronic Viral Infection (19 June 2009)
J. S. Yi et al.
The cytokine interleukin-21 has a profound impact on virus-specific T cell responses to chronic infections in mice.
See related Perspective.

IL-21R on T Cells Is Critical for Sustained Functionality and Control of Chronic Viral Infection (19 June 2009)
A. Fröhlich et al.
Thymus cells of the immune system require the cytokine interleukin-21 to control chronic viral infections.
See related Perspective.


CELL/DEVELOPMENTAL BIOLOGY

Regulation of Hypoxia-Inducible Factor 2α Signaling by the Stress-Responsive Deacetylase Sirtuin 1 (5 June 2009)
E. M. Dioum et al.
A deacetylase implicated in aging directly regulates a transcription factor that controls stress-responsive genes.
See related Perspective.

Endogenous Activation Patterns of Cdc42 GTPase Within Drosophila Embryos (5 June 2009)
D. Kamiyama and A. Chiba
Bioprobe imaging reveals precise patterns of activation for a signaling protein in the neurons of intact animals. 

Elevated C02 Enhances Otolith Growth in Young Fish (26 June 2009)
D. M. Checkley Jr. et al.
Acidification of the oceans may have unexpected effects on the development of bony structures in fish larvae. 

Dynamic Signaling Network for the Specification of Embryonic Pancreas and Liver Progenitors (26 June 2009)
E. Wandzioch and K. S. Zaret
During mammalian development, networks of signals coordinate cell-type programming into specific organs. 

Germline P Granules Are Liquid Droplets That Localize by Controlled Dissolution/Condensation (26 June 2009)
C. P. Brangwynne et al.
Localization of RNA and protein-rich germ-cell granules occurs by controlled dissolution and condensation.
See related Perspective.


BIOCHEMISTRY

Mechanoenzymatic Cleavage of the Ultralarge Vascular Protein von Willebrand Factor (5 June 2009)
X. Zhang et al.
Mechanical forces regulate the length of von Willebrand factor multimers and thus regulate thrombogenic potential.
See related Perspective.

Structure of Rotavirus Outer-Layer Protein VP7 Bound with a Neutralizing Fab (12 June 2009)
S. T. Aoki et al.
Binding of neutralizing antibodies to rotavirus stabilizes coat-protein trimers and blocks cell entry. 

Structure and Mechanism of an Amino Acid Antiporter (19 June 2009)
X. Gao et al.
The architecture of a membrane protein channel helps explain how Escherichia coli survive the acidic conditions of the stomach. 

Solution Nuclear Magnetic Resonance Structure of Membrane-Integral Diacylglycerol Kinase (26 June 2009)
W. D. Van Horn et al.
Mutations reveal the distribution of sequence changes that alter folding and affect function in a membrane-bound enzyme. 


PLANT SCIENCE

Leading-Edge Vortices Elevate Lift of Autorotating Plant Seeds (12 June 2009)
D. Lentink et al.
Winged plant seeds use leading-edge vortices to create lift, in the same way that flying animals do. 

Auxin-Dependent Patterning and Gamete Specification in the Arabidopsis Female Gametophyte (26 June 2009)
G. C. Pagnussat et al.
An auxin gradient is involved in cell fate specification of the female sex cells in flowering plants.
See related Perspective.


GENETICS

Rapid and Accurate Large-Scale Coestimation of Sequence Alignments and Phylogenetic Trees (19 June 2009)
K. Liu et al.
A step-wise algorithm iteratively wraps sequence alignment around a phylogenetic tree to reduce bias caused by errors.
See related Perspective.

Genomic Footprints of a Cryptic Plastid Endosymbiosis in Diatoms (26 June 2009)
A. Moustafa et al.
The genomes of early plant representatives are composites, with a substantial number of foreign genes from red and green algae.
See related Perspective.