Bio-Med Roundup

This month in Bio-Med Roundup:
  • Junt et al. revealed new insights into platelet production by imaging live bone marrow.
  • Allen et al. investigated the neural and hemodynamic consequences of transcranial magnetic stimulation.
  • Morrison et al. described the genome of the pathogenic intestinal parasite Giardia lamblia.
  • Lu and Fu reported the x-ray structure of the bacterial zinc transport protein YiiP.
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This month’s Bio-Med Roundup is sponsored by:
Metagenomics Webinar brought to you by Science

Viral Metagenomics Webinar – October 24, 2007, at 12 noon Eastern Daylight Time (9am PDT, 5pm GMT)

Join an online seminar on 24 October 2007 entitled "A Viral Metagenomics Study of Honey Bee Colony Collapse Disorder" presented by two eminent authors of a recently published Science paper. Gain more insight into their data as well as the technological advances that made the work possible. Pose your own questions live and in real time directly to the authors! Time is running out – register today: www.sciencemag.org/webinar

Produced by the Science Business Office and sponsored by Roche and 454 Life Sciences.



GENETICS
 
Common Sequence Variants in the LOXL1 Gene Confer Susceptibility to Exfoliation Glaucoma (7 September 2007)
G. Thorleifsson, K. P. Magnusson, P. Sulem, G. B. Walters, D. F. Gudbjartsson, H. Stefansson, T. Jonsson, A. Jonasdottir, A. Jonasdottir, G. Stefansdottir et al.
A genome-wide study reveals that a type of glaucoma characterized by accumulation of fibrillar deposits in the eye is associated with a gene variant that modifies elastin fibers.

The Fusarium graminearum Genome Reveals a Link Between Localized Polymorphism and Pathogen Specialization (7 September 2007)
C. A. Cuomo, U. Güldener, J.-R. Xu, F. Trail, B. G. Turgeon, A. Di Pietro, J. D. Walton, L.-J. Ma, S. E. Baker, M. Rep et al.
The genome of a filamentous pathogenic fungus shows excess polymorphism in regions with high levels of recombination.

Draft Genome of the Filarial Nematode Parasite Brugia malayi (21 September 2007)
E. Ghedin, S. Wang, D. Spiro, E. Caler, Q. Zhao, J. Crabtree, J. E. Allen, A. L. Delcher, D. B. Guiliano, D. Miranda-Saavedra et al.
The genome sequence of a parasitic nematode shows that, in comparison to its free-living relative Caenorhabditis elegans, its genes are adapted for its parasitic life-style.

Genomic Minimalism in the Early Diverging Intestinal Parasite Giardia lamblia (28 September 2007)
H. G. Morrison, A. G. McArthur, F. D. Gillin, S. B. Aley, R. D. Adam, G. J. Olsen, A. A. Best, W. Z. Cande, F. Chen, M. J. Cipriano et al.
The genome of the pathogenic intestinal parasite Giardia reveals simplified metabolic systems, unexpected evidence of sexual reproduction, and specialized classes of protein.
See related Perspective.

Whole-Genome Shotgun Sequencing of Mitochondria from Ancient Hair Shafts (28 September 2007)
M. T. P. Gilbert, L. P. Tomsho, S. Rendulic, M. Packard, D. I. Drautz, A. Sher, A. Tikhonov, L. Dalén, T. Kuznetsova, P. Kosintsev et al.
Mitochondrial DNA can be successfully sequenced from woolly mammoth hair kept either frozen in permafrost or at room temperature in a museum for 200 years.


BIOCHEMISTRY/STRUCTURAL BIOLOGY

Asymmetry in the Structure of the ABC Transporter–Binding Protein Complex BtuCD-BtuF (7 September 2007)
R. N. Hvorup, B. A. Goetz, M. Niederer, K. Hollenstein, E. Perozo, K. P. Locher
The structure of a bacterial transporter for vitamin B12 and its binding protein partner reveals an occluded state that may represent an intermediate step in transport.

LeuT-Desipramine Structure Reveals How Antidepressants Block Neurotransmitter Reuptake (7 September 2007)
Z. Zhou, J. Zhen, N. K. Karpowich, R. M. Goetz, C. J. Law, M. E. A. Reith, D.-N. Wang
The structure of an antidepressant drug bound to a bacterial transporter reveals how these drugs may work on neurotransmitter transporters in humans.

Cysteine Redox Sensor in PKGIα Enables Oxidant-Induced Activation (7 September 2007)
J. R. Burgoyne, M. Madhani, F. Cuello, R. L. Charles, J. P. Brennan, E. Schröder, D. D. Browning, P. Eaton
An unusual redox-triggered dimerization can, like nitric oxide, activate cyclic GMP–dependent kinase to reduce blood pressure by decreasing tension in blood vessel walls.
See related Perspective.

Crystal Structure of an Ancient Protein: Evolution by Conformational Epistasis (14 September 2007)
E. A. Ortlund, J. T. Bridgham, M. R. Redinbo, J. W. Thornton
The structure of a 450-million-year-old corticoid receptor, resurrected computationally and biochemically, suggests how modern hormone receptors evolved.

A Common Fold Mediates Vertebrate Defense and Bacterial Attack (14 September 2007)
C. J. Rosado, A. M. Buckle, R. H. P. Law, R. E. Butcher, W.-T. Kan, C. H. Bird, K. Ung, K. A. Browne, K. Baran, T. A. Bashtannyk-Puhalovich et al.

Structure of C8α-MACPF Reveals Mechanism of Membrane Attack in Complement Immune Defense (14 September 2007)
M. A. Hadders, D. X. Beringer, P. Gros
A domain structure shared by a mammalian defense protein and a bacterial toxic protein suggests that the immune proteins disrupt membranes by forming pores.

Structure of the Zinc Transporter YiiP (21 September 2007)
M. Lu and D. Fu
The crystal structure of a bacterial membrane transporter reveals that it uses an unusual two-site, zinc-for-proton exchange mechanism.
See related Perspective.

Multicolor Super-Resolution Imaging with Photo-Switchable Fluorescent Probes (21 September 2007)
M. Bates, B. Huang, G. T. Dempsey, X. Zhuang
A super-resolution imaging method that uses a family of multicolor fluorescent probes yields images of fixed cells with a spatial resolution of 20 to 30 nanometers.

Structures of the CCR5 N Terminus and of a Tyrosine-Sulfated Antibody with HIV-1 gp120 and CD4 (28 September 2007)
C. Huang, S. N. Lam, P. Acharya, M. Tang, S.-H. Xiang, S. Shahzad-ul Hussan, R. L. Stanfield, J. Robinson, J. Sodroski, I. A. Wilson et al.
A conserved region in the HIV-1 envelope glycoprotein binds to a sulfated tyrosine during entry into host cells, providing a possible target for therapeutics.


DEVELOPMENTAL BIOLOGY

Production of Trout Offspring from Triploid Salmon Parents (14 September 2007)
T. Okutsu, S. Shikina, M. Kanno, Y. Takeuchi, G. Yoshizaki
Transplantation of trout spermatogonia to newborn sterile salmon results in male and female adults that produce trout offspring, a method that may help revive extinct species.

A Vasculature-Associated Niche for Undifferentiated Spermatogonia in the Mouse Testis (21 September 2007)
S. Yoshida, M. Sukeno, Y. Nabeshima
Time-lapse imaging reveals that the stem cells that generate sperm are located near blood vessels in the testis of mice, a different organization than in invertebrates.
See related Perspective.

Synchrony Dynamics During Initiation, Failure, and Rescue of the Segmentation Clock (28 September 2007)
I. H. Riedel-Kruse, C. Müller, A. C. Oates
A model of the segmentation clock, coupled genetic oscillators that sequentially generate the body segments of animals, successfully predicts the results of system perturbations.


IMMUNOLOGY
 
TLR3 Deficiency in Patients with Herpes Simplex Encephalitis (14 September 2007)
S.-Y. Zhang, E. Jouanguy, S. Ugolini, A. Smahi, G. Elain, P. Romero, D. Segal, V. Sancho-Shimizu, L. Lorenzo, A. Puel et al.
An innate immune receptor in humans selectively protects against severe infection of the central nervous system by herpes simplex virus 1.

Anti-Inflammatory Activity of Human IgG4 Antibodies by Dynamic Fab Arm Exchange (14 September 2007)
M. van der Neut Kolfschoten, J. Schuurman, M. Losen, W. K. Bleeker, P. Martínez-Martínez, E. Vermeulen, T. H. den Bleker, L. Wiegman, T. Vink, L. A. Aarden et al.
One of the two arms of a type of antibody is often replaced, allowing binding to two different antigens and reducing cross-linking and immune responses.
See related Perspective.

Dynamic Visualization of Thrombopoiesis Within Bone Marrow (21 September 2007)
T. Junt, H. Schulze, Z. Chen, S. Massberg, T. Goerge, A. Krueger, D. D. Wagner, T. Graf, J. E. Italiano, Jr., R. A. Shivdasani, U. H. von Andrian
Imaging of living bone marrow confirms that platelets form when long protrusions from sessile cells extend through the blood vessel wall and are then sheared by blood flow.
See related Perspective.


MOLECULAR BIOLOGY
 
Functional Architecture and Evolution of Transcriptional Elements That Drive Gene Coexpression (14 September 2007)
C. D. Brown, D. S. Johnson, A. Sidow
The regulatory regions of simultaneously expressed muscle genes are unexpectedly diverse within a sea squirt species, yet each is evolutionarily conserved among species.

UHRF1 Plays a Role in Maintaining DNA Methylation in Mammalian Cells (21 September 2007)
M. Bostick, J. K. Kim, P.-O. Estève, A. Clark, S. Pradhan, S. E. Jacobsen et al.
Epigenetic DNA methylation patterns that persist through cell division depend on a protein that binds to hemimethylated DNA and a methyltransferase.

MicroRNA Inhibition of Translation Initiation in Vitro by Targeting the Cap-Binding Complex eIF4F (21 September 2007)
G. Mathonnet, M. R. Fabian, Y. V. Svitkin, A. Parsyan, L. Huck, T. Murata, S. Biffo, W. C. Merrick, E. Darzynkiewicz, Ramesh S. Pillai et al.
In vitro, microRNAs can act to repress the initial step of protein translation.


NEUROSCIENCE

Leptin Regulates Striatal Regions and Human Eating Behavior (7 September 2007)
I. S. Farooqi, E. Bullmore, J. Keogh, J. Gillard, S. O’Rahilly, P. C. Fletcher
A brain-imaging study of two leptin-deficient individuals suggests that this appetite-suppressing hormone acts to diminish the perception of food’s rewarding properties.

Transcranial Magnetic Stimulation Elicits Coupled Neural and Hemodynamic Consequences (28 September 2007)
E. A. Allen, B. N. Pasley, T. Duong, R. D. Freeman
A procedure that targets circumscribed brain regions in people and animals suppresses and desynchronizes neural activity, effects that are faithfully reflected by brain imaging methods.

The Slit Receptor EVA-1 Coactivates a SAX-3/Robo–Mediated Guidance Signal in C. elegans (28 September 2007)
K. Fujisawa, J. L. Wrana, J. G. Culotti
A previously unknown membrane receptor helps guide developing axons in the nematode nervous system.


PSYCHOLOGY
 
Humans Have Evolved Specialized Skills of Social Cognition: The Cultural Intelligence Hypothesis (7 September 2007)
E. Herrmann, J. Call, M. V. Hernàndez-Lloreda, B. Hare, M. Tomasello
Children who are 2 and a half years old deal with quantities, space, and causality as well as adult chimps but far surpass them on social learning tasks, communication, and theory of mind skills.

The Perception of Rational, Goal-Directed Action in Nonhuman Primates (7 September 2007)
J. N. Wood, D. D. Glynn, B. C. Phillips, M. D. Hauser
Apes, as well as New and Old World monkeys, can analyze goal-directed actions and infer the underlying rationale.


MICROBIOLOGY
 
Quantitative Imaging of Nitrogen Fixation by Individual Bacteria Within Animal Cells (14 September 2007)
C. P. Lechene, Y. Luyten, G. McMahon, D. L. Distel
Mapping of a rare isotope of nitrogen shows that symbiotic bacteria on the gills of shipworms fix nitrogen and transfer it to nitrogen-poor tissues of the host.
See related Perspective.

Widespread Lateral Gene Transfer from Intracellular Bacteria to Multicellular Eukaryotes (21 September 2007)
J. C. Dunning Hotopp, M. E. Clark, D. C. S. G. Oliveira, J. M. Foster, P. Fischer, M. C. Muñoz Torres, J. D. Giebel, N. Kumar, N. Ishmael, S. Wang et al.
Unexpectedly, the symbiont Wolbachia can transfer segments of DNA consisting of individual genes or almost its entire genome to its insect or nematode hosts.


This month’s Bio-Med Roundup is sponsored by:
Metagenomics Webinar brought to you by Science

Viral Metagenomics Webinar – October 24, 2007, at 12 noon Eastern Daylight Time (9am PDT, 5pm GMT)

Join an online seminar on 24 October 2007 entitled "A Viral Metagenomics Study of Honey Bee Colony Collapse Disorder" presented by two eminent authors of a recently published Science paper. Gain more insight into their data as well as the technological advances that made the work possible. Pose your own questions live and in real time directly to the authors! Time is running out – register today: www.sciencemag.org/webinar

Produced by the Science Business Office and sponsored by Roche and 454 Life Sciences.