Bio-Med Roundup

This month in Bio-Med Roundup:
  • Putnam et al. described the genome of the sea anemone, which is more similar to the genome of vertebrates than that of flies or worms.
  • Outeiro et al. found that an inhibitor of the microtubule deacetylase sirtuin 2 protects neuronal cells from the toxicity of a protein aggregate associated with Parkinson’s disease.
  • Depue et al. found evidence that regions of the prefrontal cortex orchestrate suppression of emotional memories via a two-step process.
  • Stern-Ginossar et al. showed that human cytomegalovirus expresses a microRNA that helps repress host immune responses during infection.
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This month’s Bio-Med Roundup is sponsored by:
The University of Florida Forensic Science Online Programs
The University of Florida Forensic Science Online Programs offers Master’s degrees and graduate certificates in 5 areas of study.
Designed for working scientists: Join the ranks of career-minded forensic scientists worldwide, pursuing graduate education.
Courses conducted fully online: Students interact with instructors, and other students, using course e-mail, discussion boards, and live chat sessions.
Enroll now for fall!  Visit www.ForensicScience.ufl.edu for more details.



GENETICS
 
Sea Anemone Genome Reveals Ancestral Eumetazoan Gene Repertoire and Genomic Organization (6 July 2007)
N. H. Putnam, M. Srivastava, U. Hellsten, B. Dirks, J. Chapman, A. Salamov, A. Terry, H. Shapiro, Erika Lindquist, V. V. Kapitonov et al.
The Cnidaria genome is more similar to that of vertebrates than flies or worms, suggesting that the common ancestor of multicellular animals was unexpectedly complex.

Genetic Properties Influencing the Evolvability of Gene Expression (6 July 2007)
C. R. Landry, B. Lemos, S. A. Rifkin, W. J. Dickinson, D. L. Hartl
The expression levels of genes regulated by certain nearby elements or by many distant elements evolve particularly rapidly.

Common Sequence Polymorphisms Shaping Genetic Diversity in Arabidopsis thaliana (20 July 2007)
R. M. Clark, G. Schweikert, C. Toomajian, S. Ossowski, G. Zeller, P. Shinn, N. Warthmann, T. T. Hu, G. Fu, D. A. Hinds et al.
Extensive variation in the genome sequences of 20 strains of Arabidopsis thaliana indicate a prominent role for biotic interactions in shaping its genetic diversity.

Genetic Diversity in Honey Bee Colonies Enhances Productivity and Fitness (20 July 2007)
H. R. Mattila and T. D. Seeley
Honey bee hives with genetically diverse members stored more food and thus survived better than those with members from a single male founder.


MEDICINE

Gender Disparity in Liver Cancer Due to Sex Differences in MyD88-Dependent IL-6 Production (6 July 2007)
W. E. Naugler, T. Sakurai, S. Kim, S. Maeda, K. Kim, A. M. Elsharkawy, M. Karin
The greater production of an inflammatory cytokine in male mice explains their higher susceptibility to liver cancer.
See related Perspective.

Regulation of Spontaneous Intestinal Tumorigenesis Through the Adaptor Protein MyD88 (6 July 2007)
S. Rakoff-Nahoum and R. Medzhitov
In mice, an innate immune signaling pathway controls the expression of several key genes that influence tumor development in the intestine.
See related Perspective.

Tumor Growth Need Not Be Driven by Rare Cancer Stem Cells (20 July 2007)
P. N. Kelly, A. Dakic, J. M. Adams, S. L. Nutt, A. Strasser
Many of the lymphoma and leukemia cells in mice can seed new tumors, a result inconsistent with the hypothesis that tumor growth is driven by rare cancer stem cells.

Brain IRS2 Signaling Coordinates Life Span and Nutrient Homeostasis (20 July 2007)
A. Taguchi, L. M. Wartschow, M. F. White
Mice engineered with a brain-specific decrease in insulin-like signaling have their life spans extended as much as those in mice with a similar defect throughout their bodies.

AAV Vector Integration Sites in Mouse Hepatocellular Carcinoma (27 July 2007)
A. Donsante, D. G. Miller, Y. Li, C. Vogler, E. M. Brunt, D. W. Russell, M. S. Sands
A virus that has shown promise as a vector for human gene therapy causes liver tumors in neonatal mice.

Sirtuin 2 Inhibitors Rescue α-Synuclein–Mediated Toxicity in Models of Parkinson’s Disease (27 July 2007)
T. F. Outeiro, E. Kontopoulos, S. M. Altmann, I. Kufareva, K. E. Strathearn, A. M. Amore, C. B. Volk, M. M. Maxwell, J.-C. Rochet, P. J. McLean et al.
An inhibitor of a microtubule deacetylase protects dopamine-containing cells and can rescue Drosophila from the toxicity of a protein aggregate associated with Parkinson’s disease.
See related Perspective.


NEUROSCIENCE/PSYCHOLOGY

Dentate Gyrus NMDA Receptors Mediate Rapid Pattern Separation in the Hippocampal Network (6 July 2007)
T. J. McHugh, M. W. Jones, J. J. Quinn, N. Balthasar, R. Coppari, J. K. Elmquist, B. B. Lowell, M. S. Fanselow, M. A. Wilson, S. Tonegawa
Rats are able to distinguish a new environment from a similar one because of distinct patterns of synaptic strengthening in the dentate gyrus.
See related Perspective.

Prefrontal Regions Orchestrate Suppression of Emotional Memories via a Two-Phase Process (13 July 2007)
B. E. Depue, T. Curran, M. T. Banich
During normal suppression of emotional memories, the prefrontal cortex inhibits memory-related brain regions, a process that may go awry in certain psychiatric conditions.

Mosaic Organization of Neural Stem Cells in the Adult Brain (20 July 2007)
F. T. Merkle, Z. Mirzadeh, A. Alvarez-Buylla
The various types of neurons that migrate to adult mouse olfactory cortex are each born in a different subregion of the stem cell area, the subventricular zone.

Queen Pheromone Blocks Aversive Learning in Young Worker Bees (20 July 2007)
V. Vergoz, H. A. Schreurs, A. R. Mercer
A pheromone produced by honey bee queens prevents aversive learning in workers, possibly to prevent the queen’s attendants from forming an aversion to their mother.
See related Perspective.

Rapid Synthesis and Synaptic Insertion of GluR2 for mGluR-LTD in the Ventral Tegmental Area (27 July 2007)
M. Mameli, B. Balland, R. Luján, C. Lüscher
A decrease in the effectiveness of synapses in a particular brain region is caused by replacement of one glutamate receptor subtype with a less efficient one.

Are Women Really More Talkative Than Men? (6 July 2007)
M. R. Mehl, S. Vazire, N. Ramírez-Esparza, R. B. Slatcher, J. W. Pennebaker
Contrary to popular wisdom, male and female college students speak the same number of words daily—about 15,000.


BIOCHEMISTRY/STRUCTURAL BIOLOGY
 
Mechanism of Two Classes of Cancer Mutations in the Phosphoinositide 3-Kinase Catalytic Subunit (13 July 2007)
N. Miled, Y. Yan, W.-C. Hon, O. Perisic, M. Zvelebil, Y. Inbar, D. Schneidman-Duhovny, H. J. Wolfson, J. M. Backer, R. L. Williams
Structural and functional studies suggest that mutations in two noncatalytic domains of an important kinase can cause cancer by releasing an inhibitor.
See related Perspective.

PDZ Domain Binding Selectivity Is Optimized Across the Mouse Proteome (20 July 2007)
M. A. Stiffler, J. R. Chen, V. P. Grantcharova, Y. Lei, D. Fuchs, J. E. Allen, L. A. Zaslavskaia, G. MacBeath
The variations in binding selectivity of a common protein binding domain are evenly distributed in selectivity space, rather than arranged in discrete clusters as had been assumed.

Crystal Structure of Inhibitor-Bound Human 5-Lipoxygenase–Activating Protein (27 July 2007)
A. D. Ferguson, B. M. McKeever, S. Xu, D. Wisniewski, D. K. Miller, T.-T. Yamin, R. H. Spencer, L. Chu, F. Ujjainwalla, B. R. Cunningham et al.
The structure of a human membrane protein involved in biosynthesis of the inflammation-related leukotrienes may help guide the development of therapeutics.

Spring-Loaded Mechanism of DNA Unwinding by Hepatitis C Virus NS3 Helicase (27 July 2007)
S. Myong, M. M. Bruno, A. M. Pyle, T. Ha
A helicase enzyme unwinds DNA in steps three base pairs long that periodically release the tension resulting from translocation of the helicase’s motor domain along the DNA.


MOLECULAR BIOLOGY
 
Yeast DNA Polymerase ε Participates in Leading-Strand DNA Replication (6 July 2007)
Z. F. Pursell, I. Isoz, E.-B. Lundström, E. Johansson, T. A. Kunkel
DNA polymerase ε is the elusive enzyme that replicates the leading strand of DNA in the 5’ to 3’ direction.

Postreplicative Formation of Cohesion Is Required for Repair and Induced by a Single DNA Break (13 July 2007)
L. Ström, C. Karlsson, H. Betts Lindroos, S. Wedahl, Y. Katou, K. Shirahige, C. Sjögren

DNA Double-Strand Breaks Trigger Genome-Wide Sister-Chromatid Cohesion Through Eco1 (Ctf7) (13 July 2007)
E. Ünal, J. M. Heidinger-Pauli, D. Koshland
The close association of two sister chromatids can occur as a result of DNA damage and does not require simultaneous DNA replication, as previously thought.
See related Perspective.


CELL/DEVELOPMENTAL BIOLOGY

Developmentally Regulated Activation of a SINE B2 Repeat as a Domain Boundary in Organogenesis (13 July 2007)
V. V. Lunyak, G. G. Prefontaine, E. Núñez, T. Cramer, B.-G. Ju, K. A. Ohgi, K. Hutt, R. Roy, A. García-Díaz, X. Zhu et al.
A repetitive DNA segment in the growth hormone gene is transcribed during pituitary development and establishes chromatin structure for activation of gene transcription.

Combinatorial ShcA Docking Interactions Support Diversity in Tissue Morphogenesis (13 July 2007)
W. R. Hardy, L. Li, Z. Wang, J. Sedy, J. Fawcett, E. Frank, J. Kucera, T. Pawson
Distinct subsets of the available interaction domains of a scaffolding protein are recruited in muscle and heart to support tissue-specific developmental programs.

Patched1 Regulates Hedgehog Signaling at the Primary Cilium (20 July 2007)
R. Rohatgi, L. Milenkovic, M. P. Scott
Signaling on cilia occurs when a soluble ligand binds to a receptor and relieves an inhibitory interaction, allowing regulation of development and other processes.
See related Perspective.


IMMUNOLOGY
 
Host Resistance to Lung Infection Mediated by Major Vault Protein in Epithelial Cells (6 July 2007)
M. P. Kowalski, A. Dubouix-Bourandy, M. Bajmoczi, D. E. Golan, T. Zaidi, Y. S. Coutinho-Sledge, M. P. Gygi, S. P. Gygi, E. A. C. Wiemer, G. B. Pier
A protein in vaults, a cellular ribonucleoprotein, is necessary for lung epithelial cells to deal with a bacterial infection common in the lungs of cystic fibrosis patients.

Reciprocal TH17 and Regulatory T Cell Differentiation Mediated by Retinoic Acid (13 July 2007)
D. Mucida, Y. Park, G. Kim, O. Turovskaya, I. Scott, M. Kronenberg, H. Cheroutre
The decision to promote distinct immune cells, which either prevent or promote inflammation, is regulated by the vitamin A metabolite retinoic acid.

Host Immune System Gene Targeting by a Viral miRNA (20 July 2007)
N. Stern-Ginossar, N. Elefant, A. Zimmermann, D. G. Wolf, N. Saleh, M. Biton, E. Horwitz, Z. Prokocimer, M. Prichard, G. Hahn, D. Goldman-Wohl et al.
Cytomegalovirus aids its own survival by encoding a microRNA that inhibits, in the infected host cell, translation of a ligand that would normally trigger antiviral responses.
See related Perspective.


MICROBIOLOGY
 
Candidatus Chloracidobacterium thermophilum: An Aerobic Phototrophic Acidobacterium (27 July 2007)
D. A. Bryant, A. M. Garcia Costas, J. A. Maresca, A. G. M. Chew, C. G. Klatt, M. M. Bateson, L. J. Tallon, J. Hostetler, W. C. Nelson, J. F. Heidelberg, D. M. Ward
A distinctive, oxygen-tolerant photosynthetic bacterium has been identified in a metagenomic study of hot-spring communities in Yellowstone National Park.

Noise in Gene Expression Determines Cell Fate in Bacillus subtilis (27 July 2007)
H. Maamar, A. Raj, D. Dubnau
Bacteria that show more random fluctuations in gene expression are especially likely to switch to an alternative phenotype in which they can take up foreign genetic material.
See related Perspective.


PLANT SCIENCE
 
Ethylene Modulates Stem Cell Division in the Arabidopsis thaliana Root (27 July 2007)
O. Ortega-Martínez, M. Pernas, R. J. Carol, L. Dolan
Stem cell proliferation in a niche within developing roots is limited by the gaseous hormone ethylene.


This month’s Bio-Med Roundup is sponsored by:
The University of Florida Forensic Science Online Programs 
The University of Florida Forensic Science Online Programs offers Master’s degrees and graduate certificates in 5 areas of study.
Designed for working scientists: Join the ranks of career-minded forensic scientists worldwide, pursuing graduate education.
Courses conducted fully online: Students interact with instructors, and other students, using course e-mail, discussion boards, and live chat sessions.
Enroll now for fall!  Visit www.ForensicScience.ufl.edu for more details.