This month in Bio-Med Roundup:

• Munster et al. and Maines et al. use ferrets, a model system for human influenza, to examine the pathogenesis and transmission of swine-origin 2009 A(H1N1) influenza viruses.
• Briggs et al. used a new method of ancient DNA sequence retrieval to reconstruct the complete mitochondrial DNA genomes of five Neandertals.
• Imai et al. found that that axon-axon interactions organize olfactory axons before they reach their target in the mouse brain.
• Tzur et al. showed that control over cell division depends on coordinately functioning sensors of cell size and age.

Jump to:

• Neuroscience
• Cell Biology
• Molecular Biology
• Immunology
• Genetics
• Microbiology/Virology
• Medicine
• Physiology/Anatomy
• Genetics
• Biochemistry

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NEUROSCIENCE
 
Dissociable Components of Rule-Guided Behavior Depend on Distinct Medial and Prefrontal Regions (3 July 2009)
M. J. Buckley et al.
A card-sorting task shows that three distinct regions of the monkey prefrontal cortex perform distinct cognitive functions. 

Role of Layer 6 of V2 Visual Cortex in Object-Recognition Memory (3 July 2009)
M. F. López-Aranda et al.
Experiments reveal the localization of short- and long-term visual memory encoding in the rat visual cortex.
See related Perspective.

Traction on Immobilized Netrin-1 Is Sufficient to Reorient Axons (10 July 2009)
S. W. Moore et al.
Advancing spinal neuron growth cones generate traction forces that can direct the trajectory of the axon. 

Induction of Synaptic Long-Term Potentiation After Opioid Withdrawal (10 July 2009)
R. Drdla et al.
Withdrawal from opioids in rats induces an increase in synaptic strength in pain pathways and thereby enhances pain sensitivity. 

A Functional Role for Adult Hippocampal Neurogenesis in Spatial Pattern Separation (10 July 2009)
C. D. Clelland et al.
Disruption of neurogenesis in a neuron-forming site in the brain impairs spatial memory functions in mice. 

Translocator Protein (18 kD) as Target for Anxiolytics Without Benzodiazepine-Like Side Effects (24 July 2009)
R. Rupprecht et al.
Possible drug alternative for rapid treatment of anxiety disorders could replace benzodiazepines. 

Pre-Target Axon Sorting Establishes the Neural Map Topography (31 July 2009)
T. Imai et al.
The mouse olfactory topographic neural map is self-organized by interactions between axons, not directed by the target. 
See related Perspective. 

Flexible Learning of Multiple Speech Structures in Bilingual Infants (31 July 2009)
Á. M. Kovács and J. Mehler
Exposure to two languages facilitates the development of a more flexible associative learning capacity. 

Chronic Stress Causes Frontostriatal Reorganization and Affects Decision-Making (31 July 2009)
E. Dias-Ferreira et al.
Chronic stress alters brain neural circuits and affects the ability of animals to perform actions based on their consequences. 


CELL BIOLOGY

Ligand-Gated Chloride Channels Are Receptors for Biogenic Amines in C. elegans (3 July 2009)
N. Ringstad et al.
An expanded family of receptor channels that bind neurotransmitters in worms might help to explain behavioral effects in humans. 

LXR Regulates Cholesterol Uptake Through Idol-Dependent Ubiquitination of the LDL Receptor (3 July 2009)
N. Zelcer et al.
Cholesterol metabolism is regulated by a signaling pathway that targets the LDL receptor for degradation. 

Cell Growth and Size Homeostasis in Proliferating Animal Cells (10 July 2009)
A. Tzur et al.
Lymphoblasts grow slowly after mitosis, then reach a constant exponential rate, indicating an active size-control mechanism. 
See related Perspective. 

Hematopoietic Cytokines Can Instruct Lineage Choice (10 July 2009)
M. A. Rieger et al.
Single-cell tracking proves that physiological cytokines determine the developmental fate of hematopoietic progenitor cells. 

RIP3, an Energy Metabolism Regulator That Switches TNF-Induced Cell Death from Apoptosis to Necrosis (17 July 2009)
D.-W. Zhang et al.
The protein kinase RIP3 mediates necrotic cell death, likely through regulation of metabolic enzymes. 

Dependence of Mouse Embryonic Stem Cells on Threonine Catabolism (24 July 2009)
J. Wang et al.
Mouse embryonic stem cells exist in a high-flux metabolic state comparable to that of rapidly dividing bacteria. 

A Gene Network Regulating Lysosomal Biogenesis and Function (24 July 2009)
M. Sardiello et al.
Coordination of the genes that regulate lysosomal biogenesis occurs via a shared sequence motif and one transcription factor. 

An ER-Mitochondria Tethering Complex Revealed by a Synthetic Biology Screen (24 July 2009)
B. Kornmann et al.
A protein complex zippers mitochondria to endoplasmic reticulum for phospholipid transfer. See related Perspective. 

The cAMP Sensor Epac2 Is a Direct Target of Antidiabetic Sulfonylurea Drugs (31 July 2009)
C.-L. Zhang et al.
A drug used to enhance insulin secretion in diabetes has a previously unrecognized protein target. 


MOLECULAR BIOLOGY

Jmjd6 Catalyses Lysyl-Hydroxylation of U2AF65, a Protein Associated with RNA Splicing (3 July 2009)
C. J. Webby et al.
An oxygenase with an important role in vertebrate development hydroxylates a messenger RNA splicing factor. 

Essential Role of the Glycosyltransferase Sxc/Ogt in Polycomb Repression (3 July 2009)
M. C. Gambetta et al.
The Polycomb-group protein super sex combs acts to glycosylate a second Polycomb repressor protein. 
See related Perspective. 

Reversal of RNA Dominance by Displacement of Protein Sequestered on Triplet Repeat RNA (17 July 2009)
T. M. Wheeler et al.
An antisense oligonucleotide ameliorates the symptoms of myotonic dystrophy in transgenic mice. 
See related Perspective. 

Synchronous and Stochastic Patterns of Gene Activation in the Drosophila Embryo (24 July 2009)
A. N. Boettiger and M. Levine
Synchronous activation of genes with stalled RNA polymerase improves transcriptional coordination. 

Nucleosomal Fluctuations Govern the Transcription Dynamics of RNA Polymerase II (31 July 2009)
C. Hodges et al.
RNA polymerase acts as a molecular ratchet to force its way through nucleosome-infested DNA. 
See related Perspective. 


IMMUNOLOGY

IRAP Identifies an Endosomal Compartment Required for MHC Class I Cross-Presentation (10 July 2009)
L. Saveanu et al.
Immunological dendritic cells contain an endocytic compartment involved in the cross-presentation of internalized antigens. 

Genome-Wide RNAi Screen Identifies Genes Involved in Intestinal Pathogenic Bacterial Infection (17 July 2009)
S. J. F. Cronin et al.
In vivo RNA interference screen reveals regulators of innate immunity in Drosophila. 

Identification of Splenic Reservoir Monocytes and Their Deployment to Inflammatory Sites (31 July 2009)
F. K. Swirski et al.
A rapid deployment force of immune cells is identified in the spleen that is important for resolving inflammation. 
See related Perspective. 

Innate and Adaptive Immunity Cooperate Flexibly to Maintain Host-Microbiota Mutualism (31 July 2009)
E. Slack et al.
Mouse immune systems interact to ensure tolerance to nonpathogenic bacteria in the gut. 


MICROBIOLOGY/VIROLOGY

Meningococcal Type IV Pili Recruit the Polarity Complex to Cross the Brain Endothelium (3 July 2009)
M. Coureuil et al.
Adhesion of bacteria to cells lining blood vessels in the brain induces them to part and allows pathogen invasion.
 
Antigenic and Genetic Characteristics of Swine-Origin 2009 A(H1N1) Influenza Viruses Circulating in Humans (10 July 2009)
R. J. Garten et al.
Evolutionary analysis suggests a triple reassortant avian-to-pig origin for the 2009 influenza A(H1N1) outbreak. 

Discovery of Swine as a Host for the Reston ebolavirus (10 July 2009)
R. W. Barrette et al.
Respiratory infections in pigs in the Philippines are associated with a cocktail of viruses, including a monkey filovirus. 

Chlamydomonas Swims with Two "Gears" in a Eukaryotic Version of Run-and-Tumble Locomotion (24 July 2009)
M. Polin et al.
Algal cilia beat synchronously for forward movement and asynchronously for turning. 
See related Perspective. 


MEDICINE

Demographic Variability, Vaccination, and the Spatiotemporal Dynamics of Rotavirus Epidemics (17 July 2009)
V. E. Pitzer et al.
Diarrhea-causing rotavirus epidemics can be predicted by shifts in birth rate rather than by seasonal variables. 
See related Perspective. 

Functional Amyloids as Natural Storage of Peptide Hormones in Pituitary Secretory Granules (17 July 2009)
S. K. Maji et al.
Peptide and protein hormones are stored in secretory granules in a nonpathological amyloid conformation. 

Pathogenesis and Transmission of Swine-Origin 2009 A(H1N1) Influenza Virus in Ferrets (24 July 2009)
V. J. Munster et al. 
Transmission and Pathogenesis of Swine-Origin 2009 A(H1N1) Influenza Viruses in Ferrets and Mice (24 July 2009)
T. R. Maines et al. 
Animal experiments compare the dynamics and effects of the virus causing the 2009 flu outbreak to those of seasonal H1N1 flu.


PHYSIOLOGY/ANATOMY

Caloric Restriction Delays Disease Onset and Mortality in Rhesus Monkeys (10 July 2009)
R. J. Colman et al.
Age-associated death and onset of pathologies are delayed by controlled caloric restriction, thus prolonging life span.
 
Modern Riding Style Improves Horse Racing Times (17 July 2009)
T. Pfau et al.
Increased horse race speed over the past century can be attributed to the crouching posture and increased work done by jockeys. 

Heat Exchange from the Toucan Bill Reveals a Controllable Vascular Thermal Radiator (24 July 2009)
G. J. Tattersall et al.
Toucans alter blood flow to their massive bills according to ambient conditions. 


GENETICS

Targeted Retrieval and Analysis of Five Neandertal mtDNA Genomes (17 July 2009)
A. W. Briggs et al.
Targeted sequencing improves Neandertal mitochondrial DNA retrieval and reveals low diversity among individuals. 

Knockout Rats via Embryo Microinjection of Zinc-Finger Nucleases (24 July 2009)
A. M. Geurts et al.
Targeted gene disruption in rats paves the way for new human disease models. 


BIOCHEMISTRY

The Human SepSecS-tRNA^Sec Complex Reveals the Mechanism of Selenocysteine Formation (17 July 2009)
S. Palioura et al.
A crystal structure shows how a pyroxidal phosphate enzyme catalyzes formation of selenocysteine from phosphoserine on transfer RNA. 

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