This month in Bio-Med Roundup:

• Pisitkun et al . and Kumar et al . offered genetic insights into the autoimmune disease lupus.
• Lanford et al . presented evidence which suggests that mice have a rudimentary form of empathy.
• Paredez et al . showed that microtubules provide tracks for the cellulose fibers that encircle and support plant cells.
• Gill et al . presented a detailed metagenomic analysis of human intestinal microflora.

• Cell/Developmental Biology
• Microbiology
• Structural Biology
• Medicine
• Immunology
• Molecular Biology
• Neuroscience
• Psychology
• Plant Science

CELL/DEVELOPMENTAL BIOLOGY

Checkpoint Proteins Control Survival of the Postmitotic Cells in Caenorhabditis elegans ( 2 June 2006 )
A. Olsen, M. C. Vantipalli, G. J. Lithgow
In C. elegans , a cell cycle protein unexpectedly functions in postmitotic tissues, where it regulates cell survival and stress-related life span.
http://www.sciencemag.org/cgi/content/abstract/312/5778/1381

Juvenile Hormone Is Required to Couple Imaginal Disc Formation with Nutrition in Insects ( 2 June 2006 )
J. W. Truman, K. Hiruma, J. P. Allee, S. G. B. MacWhinnie, D. T. Champlin, L. M. Riddiford
A hormone permits cells in developing insect larvae to divide when nutrients are available; later its reduction triggers the cells' differentiation into adult phenotypes.
http://www.sciencemag.org/cgi/content/abstract/312/5778/1385
See related Perspective at http://www.sciencemag.org/cgi/content/summary/312/5778/1317

p53 Regulates Mitochondrial Respiration ( 16 June 2006 )
S. Matoba, J.-G. Kang, W. D. Patino, A. Wragg, M. Boehm, O. Gavrilova, P. J. Hurley, F. Bunz, P. M. Hwang
Cancer cells can survive in low-oxygen conditions because a defect in a common tumor suppressor inhibits mitochondrial respiration, allowing glycolysis to take place.
http://www.sciencemag.org/cgi/content/abstract/312/5780/1650

TRB3 Links the E3 Ubiquitin Ligase COP1 to Lipid Metabolism ( 23 June 2006 )
L. Qi, J. E. Heredia, J. Y. Altarejos, R. Screaton, N. Goebel, S. Niessen, I. X. MacLeod, C. W. Liew, R. N. Kulkarni, J. Bain et al.
A protein that regulates the degradation of acetyl-CoA carboxylase, the rate-limiting enzyme in fatty acid synthesis, confers resistance to diet-induced obesity.
http://www.sciencemag.org/cgi/content/abstract/312/5781/1763
See related Perspective at http://www.sciencemag.org/cgi/content/summary/312/5781/1756

JETLAG Resets the Drosophila Circadian Clock by Promoting Light-Induced Degradation of TIMELESS ( 23 June 2006 )
K. Koh, X. Zheng, A. Sehgal
A light pulse changes the phase of the Drosophila circadian clock by activating a protein that marks a clock component for rapid degradation.
http://www.sciencemag.org/cgi/content/abstract/312/5781/1809

Lhx2 Maintains Stem Cell Character in Hair Follicles ( 30 June 2006 )
H. Rhee, L. Polak, E. Fuchs
A newly described transcription factor maintains the stem cells in the hair follicle in an undifferentiated state, preventing pre m a t u re differentiation.
http://www.sciencemag.org/cgi/content/abstract/312/5782/1946



MICROBIOLOGY

Metagenomic Analysis of the Human Distal Gut Microbiome ( 2 June 2006 )
S. R. Gill, M. Pop, R T. DeBoy, PB. Eckburg, P J. Turnbaugh, B S. Samuel, J I. Gordon, D A. Relman, C. M. Fraser-Liggett, K. E. Nelson
Sequencing the trillions of microbes in the human colon identifies genes involved in the digestion of plant carbohydrates, the fermentation of fiber, and vitamin synthesis.
http://www.sciencemag.org/cgi/content/abstract/312/5778/1355

Tim50 Maintains the Permeability Barrier of the Mitochondrial Inner Membrane ( 9 June 2006 )
M. Meinecke, R. Wagner, P. Kovermann, B. Guiard, D. U. Mick, D. P. Hutu, W. Voos, K. N. Truscott, A. Chacinska, N. Pfanner, P. Rehling
An opportunistic bacterial pathogen found in patients with cystic fibrosis contains a previously undescribed secretory apparatus that may be necessary for its virulence.
http://www.sciencemag.org/cgi/content/abstract/312/5779/1523

A Virulence Locus of Pseudomonas aeruginosa Encodes a Protein Secretion Apparatus ( 9 June 2006 )
J. D. Mougous, M. E. Cuff, S. Raunser, A. Shen, M. Zhou, C. A. Gifford, A. L. Goodman, Gr. Joachimiak, C. L. Ordoñez, S. Lory et al.
A regulatory protein blocks the large channels in the mitochondrial inner membrane, maintaining the mitchondrion's essential proton gradient.
http://www.sciencemag.org/cgi/content/abstract/312/5779/1526

Metagenomic Analysis of Coastal RNA Virus Communities ( 23 June 2006 )
A. I. Culley, A. S. Lang, C. A. Suttle
Previously unknown RNA viruses are abundant in coastal marine ecosystems; a few dominant species probably infect protists and plants.
http://www.sciencemag.org/cgi/content/abstract/312/5781/1795

Bacterial Diversity in Tree Canopies of the Atlantic Forest ( 30 June 2006 )
M. R. Lambais, D. E. Crowley, J. C. Cury, R. C. Büll, R. R. Rodrigues
The leaves of Brazilian coastal forest trees can harbor hundreds of bacterial species, most of them newly described, with a different subset on each species of tree.
http://www.sciencemag.org/cgi/content/abstract/312/5782/1917

The Competitive Cost of Antibiotic Resistance in Mycobacterium tuberculosis ( 30 June 2006 )
S. Gagneux, C. D. Long, P. M. Small, T. Van, G. K. Schoolnik, B. J. M. Bohannan
Although the tuberculosis bacterium incurs fitness costs when it acquires resistance to antibiotics, the more prevalent strains in humans exhibit superior compensation.
http://www.sciencemag.org/cgi/content/abstract/312/5782/1944



STRUCTURAL BIOLOGY

Outer Membrane Active Transport: Structure of the BtuB:TonB Complex ( 2 June 2006 )
D. D. Shultis, M. D. Purdy, C. N. Banchs, M. C. Wiener
http://www.sciencemag.org/cgi/content/abstract/312/5778/1396

Structure of TonB in Complex with FhuA, E. coli Outer Membrane Receptor ( 2 June 2006 )
P. D. Pawelek, N. Croteau, C. Ng-Thow-Hing, C. M. Khursigara, N. Moiseeva, M. Allaire, J. W. Coulton
http://www.sciencemag.org/cgi/content/abstract/312/5778/1399
Vitamins and iron are transported into bacteria through a pore in the outer membrane, assisted by a protein that induces a strand to form in the plug of the pore.

The Structure of an Infectious P22 Virion Shows the Signal for Headful DNA Packaging ( 23 June 2006 )
G. C. Lander, L. Tang, S. R. Casjens, E. B. Gilcrease, P. Prevelige, A. Poliakov, C. S. Potter, B. Carragher, J. E. Johnson
During assembly of an infectious virus, DNAis packed into the viral head t h rough a protein portal; when the head is full, pre s s u re on the portal causes it to close.
http://www.sciencemag.org/cgi/content/abstract/312/5781/1791

Structural Basis of RNA-Dependent Recruitment of Glutamine to the Genetic Code ( 30 June 2006 )
H. Oshikane, K. Sheppard, S. Fukai, Y. Nakamura, R. Ishitani, T. Numata, R. L. Sherrer, L. Feng, E. Schmitt, M. Panvert et al.
http://www.sciencemag.org/cgi/content/abstract/312/5782/1950

Ammonia Channel Couples Glutaminase with Transamidase Reactions in GatCAB ( 30 June 2006 )
A. Nakamura, M. Yao, S. Chimnaronk, N. Sakai , I. Tanaka
Bacteria and archaea use multimeric enzyme complexes to covert glutamate bound to transfer RNA to glutamine before it is added to growing peptide chains.
http://www.sciencemag.org/cgi/content/abstract/312/5782/1954



MEDICINE

Onset and Progression in Inherited ALS Determined by Motor Neurons and Microglia ( 2 June 2006 )
S. Boillée, K. Yamanaka, C. S. Lobsiger, N. G. Copeland, N. A. Jenkins, G. Kassiotis, G. Kollias, D.W. Cleveland
A gene mutation in mouse motor neurons triggers degeneration typical of ALS (Lou Gehrig's disease) and, when present in surrounding cells, exacerbates disease progression.
http://www.sciencemag.org/cgi/content/abstract/312/5778/1389

Preserved CD4+ Central Memory T Cells and Survival in Vaccinated SIV-Challenged Monkeys ( 9 June 2006 )
N. L. Letvin, J. R. Mascola, Y. Sun, D. A. Gorgone, A. P. Buzby, L. Xu, Z. Yang, B. Chakrabarti, S. S. Rao, J. E. Schmitz et al.
Monkeys infected with a cousin of the HIV virus and showing a robust immediate immune response have better immune memory for the virus later and survive longer.
http://www.sciencemag.org/cgi/content/abstract/312/5779/1530

Neuronal Pathway from the Liver Modulates Energy Expenditure and Systemic Insulin Sensitivity ( 16 June 2006 )
K. Uno, H. Katagiri, T. Yamada, Y. Ishigaki, T. Ogihara, J. Imai, Y. Hasegawa, J. Gao, K. Kaneko, H. Iwasaki et al.
A neuronal pathway that exchanges metabolic signals between liver and peripheral fat helps to coordinate energy balance in mammals.
http://www.sciencemag.org/cgi/content/abstract/312/5780/1656



IMMUNOLOGY

Regulation of B Cell Tolerance by the Lupus Susceptibility Gene Ly108 ( 16 June 2006 )
K. R. Kumar, L. Li, M. Yan, M. Bhaskarabhatla, A. B. Mobley, C. Nguyen, J. M. Mooney, J. D. Schatzle, E. K. Wakeland, C. Mohan
Mice with a genetic variant of a protein that helps eliminate cells making self-reactive antibodies are more likely to suffer from an autoimmune disease.
http://www.sciencemag.org/cgi/content/abstract/312/5780/1665
See related Perspective at http://www.sciencemag.org/cgi/content/summary/312/5780/1606

Autoreactive B Cell Responses to RNA-Related Antigens Due to TLR7 Gene Duplication ( 16 June 2006 )
P. Pisitkun, J. A. Deane, M. J. Difilippantonio, T. Tarasenko, A. B. Satterthwaite, S. Bolland
Genetic duplication of an innate immune receptor on the Y chromosome makes male mice more susceptible to the development of a lupus-like autoimmune disorder.
http://www.sciencemag.org/cgi/content/abstract/312/5780/1669
See related Perspective at http://www.sciencemag.org/cgi/content/summary/312/5780/1606

Extrafollicular Activation of Lymph Node B Cells by Antigen-Bearing Dendritic Cells ( 16 June 2006 )
H. Qi, J. G. Egen, A. Y. C. Huang, R. N. Germain
Images of living tissue show that antibody-producing cells moving from the blood to the lymph node are unexpectedly activated by specialized antigen- presenting cells.
http://www.sciencemag.org/cgi/content/abstract/312/5780/1672



MOLECULAR BIOLOGY

The Xist RNA Gene Evolved in Eutherians by Pseudogenization of a Protein-Coding Gene ( 16 June 2006 )
L. Duret, C. Chureau, S. Samain, J. Weissenbach, P. Avner
A noncoding RNA that silences extra copies of sex chromosomes evolved from a gene that lost its protein-coding function after the eutherian-marsupial divergence.
http://www.sciencemag.org/cgi/content/abstract/312/5780/1653

A Topoisomerase IIß-Mediated dsDNA Break Required for Regulated Transcription ( 23 June 2006 )
B.-G. Ju, V. V. Lunyak, V. Perissi, I. Garcia-Bassets, D. W. Rose, C. K. Glass, M. G. Rosenfeld
Estrogen-initiated gene transcription involves enzymatically driven DNA cleavage, repair, and local reconfiguration of chromatin.
http://www.sciencemag.org/cgi/content/abstract/312/5781/1798
See related Perspective at http://www.sciencemag.org/cgi/content/summary/312/5781/1752

Intron Removal Requires Proofreading of U2AF/3' Splice Site Recognition by DEK ( 30 June 2006 )
L. M. Mendes Soares, K. Zanier, C. Mackereth, M. Sattler, J. Valcárcel
A chromatin- and RNA-associated protein that is frequently mutated in leukemias ensures accurate recognition of splice sites by splicing factors.
http://www.sciencemag.org/cgi/content/abstract/312/5782/1961
See related Perspective at http://www.sciencemag.org/cgi/content/summary/312/5782/1886



NEUROSCIENCE

Long-Term Potentiation of Neuron-Glia Synapses Mediated by Ca²⁺-Permeable AMPA Receptors ( 9 June 2006 )
W.-P. Ge, X.-J. Yang, Z. Zhang, H.-K. Wang, W. Shen, Q.-D. Deng, S. Duan
Synapses between hippocampal neurons and nearby glial cells can become stronger after stimulation, just as excitatory neuron-neuron synapses can show long-term potentiation.
http://www.sciencemag.org/cgi/content/abstract/312/5779/1533

Language Control in the Bilingual Brain ( 9 June 2006 )
J. Crinion, R. Turner, A. Grogan, T. Hanakawa, U. Noppeney, J. T. Devlin, T. Aso, S. Urayama, H. Fukuyama, K. Stockton et al.
As bilingual people speak one language and then the other, their basal ganglia switch the specific processing circuits accordingly.
http://www.sciencemag.org/cgi/content/abstract/312/5779/1537

Cortex Is Driven by Weak but Synchronously Active Thalamocortical Synapses ( 16 June 2006 )
R. M. Bruno and B. Sakmann
Electrical recordings from cortical neurons in living rodents show that the numerous sensory inputs to these cells are individually weak but very effective because they act synchronously.
http://www.sciencemag.org/cgi/content/abstract/312/5780/1622
See related Perspective at http://www.sciencemag.org/cgi/content/summary/312/5780/1604

Synaptic Amplifier of Inflammatory Pain in the Spinal Dorsal Horn ( 16 June 2006 )
H. Ikeda, J. Stark, H. Fischer, M. Wagner, R. Drdla, T. Jäger, J. Sandkühler
Chronic inflammatory pain results from long-term potentiation at spinal cord synapses, which can be triggered by irregular, low-frequency input such as occurs after an injury.
http://www.sciencemag.org/cgi/content/abstract/312/5780/1659

The Muscle Protein Dok-7 Is Essential for Neuromuscular Synaptogenesis ( 23 June 2006 )
K. Okada, A. Inoue, M. Okada, Y. Murata, S. Kakuta, T. Jigami, S. Kubo, H. Shiraishi, K. Eguchi, M. Motomura et al.
A newly described protein is required for normal formation of the neuromuscular junction, where it binds to a signaling protein and causes receptor clustering.
http://www.sciencemag.org/cgi/content/abstract/312/5781/1802



PSYCHOLOGY

Costly Punishment Across Human Societies ( 23 June 2006 )
J. Henrich, R. McElreath, A. Barr, J. Ensminger, C. Barrett, A. Bolyanatz, J. C. Cardenas, M. Gurven, E. Gwako, N. Henrich et al.
People from 15 different cultures are all willing to punish others who exhibit selfish behavior that increases societal inequity, but the extent varies widely.
http://www.sciencemag.org/cgi/content/abstract/312/5781/1767

Social Modulation of Pain as Evidence for Empathy in Mice ( 30 June 2006 )
D. J. Langford, S. E. Crager, Z. Shehzad, S. B. Smith, S. G. Sotocinal, J. S. Levenstadt, M. L. Chanda, D. J. Levitin, J. S. Mogil
Mice show empathy-like behavior, exhibiting enhanced pain sensitivity when they see a familiar mouse experience pain but not when the other mouse is a stranger.
http://www.sciencemag.org/cgi/content/abstract/312/5782/1967



PLANT SCIENCE

An SNP Caused Loss of Seed Shattering During Rice Domestication ( 2 June 2006 )
S. Konishi, T. Izawa, S. Yang Lin, K. Ebana, Y. Fukuta, T. Sasaki, M. Yano
A gene that cont rols the re t e ntion of rice grains on the plant after ripening is from a transcription factor of a different class from that of another recently identified gene for this trait.
http://www.sciencemag.org/cgi/content/abstract/312/5778/1392
See related Perspective at http://www.sciencemag.org/cgi/content/summary/312/5778/1318

Visualization of Cellulose Synthase Demonstrates Functional Association with Microtubules ( 9 June 2006 )
A. R. Paredez, C. R. Somerville, D. W. Ehrhardt
Cellulose synthase makes and deposits cellulose along plant cell walls as it is carried along microtubules.
http://www.sciencemag.org/cgi/content/abstract/312/5779/1491
See related Perspective at http://www.sciencemag.org/cgi/content/summary/312/5779/1482

TOPLESS Regulates Apical Embryonic Fate in Arabidopsis ( 9 June 2006 )
J. A. Long, C. Ohno, Z. R. Smith, E. M. Meyerowitz
A gene product specifies which cells make up the plant shoot by coordinating repression of transcription, probably of root-associated genes.
http://www.sciencemag.org/cgi/content/abstract/312/5779/1520

Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO 2 Concentrations ( 30 June 2006 )
S. P. Long, E. A. Ainsworth, A. D. B. Leakey, J. Nösberger, D. R. Ort
In open-field experiments testing how increased carbon dioxide improves crop yields, the values were half those of previous experiments conducted in enclosures.
http://www.sciencemag.org/cgi/content/abstract/312/5782/1918
See related Perspective at http://www.sciencemag.org/cgi/content/summary/312/5782/1889