****************************************************NATURE************************************************
(http://www.nature.com/nature)
[1] Protein determines fate of reproductive cells in mice
DOI: 10.1038/nature03813
A known transcriptional factor plays a critical role in the specification of germ cells in mice, according to an advance online publication from Nature. This article identifies one of the earliest regulators of germ cell specification, and adds to our understanding of when this specification occurs during development.
In mice, germ cells (or reproductive cells) are induced in the so-called epiblast, which also gives rise to all other body cells. The specification and segregation of mouse germ cells from other cells are important steps in the early development of an embryo.
In new work, M. Azim Surani and colleagues show that a critical player in these events is the protein Blimp1, which is a known transcriptional repressor. Although the authors do not know how this protein regulates germ cell specification, they do show that disrupting the protein blocks germ cell formation.
Author contact:
M. Azim Surani (University of Cambridge, UK)
Tel: +44 1223 334088/334136, E-mail: [email protected]
***********************************************NATURE MATERIALS*************************************
(http://www.nature.com/naturematerials)
[2] Watching cells budge
DOI: 10.1038/nmat1404
What is the difference between biological cells and a Venetian vase? A report in the July issue of Nature Materials suggests a startling analogy between these totally different objects.
As they go about their daily business of adhering and spreading, crawling and invading, contracting and relaxing, cells display a mechanical behaviour that can be related to that of soft glass, the material used to produce fine glassware. An international group of researchers came to this conclusion after studying the motion and deformation of the cytoskeleton, a scaffold made of proteins that spans the inside of the cell and gives it shape. But whereas the state of soft glass is dependent on an external factor (the amount of heat applied by the glass blower), cells have a way of self-regulating the energy supply and drive the reorganization of their cytoskeleton themselves.
Exactly how the cells manage this reorganization is not quite understood. Importantly, scientists now have an alternative viewpoint for observing the dynamics of cells at a scale that is in between molecular events and macroscopic cellular functions, which may help them find the links between these two dimensions.
Author contact:
Predrag Bursac (School of Public Health, Harvard University, Boston, MA, USA)
Tel:+1 617 432 1362, E-mail: [email protected]
Other papers from Nature Materials to be published online at the same time and with the same embargo:
[3] Mechanical properties of ultrahigh-strength gold nanowires
DOI: 10.1038/nmat1403
[4] Controlled assembly of jammed colloidal shells on fluid droplets
DOI: 10.1038/nmat1412
[5] A triple-network tricontinuous cubic liquid crystal
DOI: 10.1038/nmat1413
*************************************NATURE CHEMICAL BIOLOGY ***********************************
(http://www.nature.com/nchembio)
[6] Flopping into dimerization
DOI: 10.1038/nchembio712
Retroviruses, including HIV, contain two molecules of RNA as their genomic information. An important step for infectivity is when the two pieces of RNA come together to form a dimer - a special kind of polymer formed of two pieces stuck together. A paper in the July issue of Nature Chemical Biology reports that part of the region involved in dimer formation is unexpectedly floppy - opening up new possibilities for exploring how viral infectivity is controlled.
Using a chemical approach, the authors investigated the structure of the dimerization domain. They added in a small molecule which could only react with nucleotides - individual bases of RNA - that were not tightly packed with other nucleotides. With this method, the authors were able to label parts of the dimerization domain that were unstructured. Surprisingly, the authors found that a region of the dimerization domain, which was formerly believed to adopt a stable packing interaction called a hairpin, is in fact flexible.
This new information about the RNA structure may have important implications for understanding retrovirus infectivity in vivo.
Author contact:
Kevin M. Weeks (University of North Carolina at Chapel Hill, NC, USA)
Tel: +1 919 962 7486, E-mail: [email protected]
************************************************NATURE MEDICINE***************************************
(http://www.nature.com/naturemedicine)
[7] Vaccine against Ebola and Marburg viruses effective in primates
DOI: 10.1038/nm1258
A paper in the July issue of Nature Medicine reports the development of a vaccine that successfully protects non-human primates against Ebola and Marburg viruses, and is the first time a Marburg vaccination has been shown to work in a monkey model.
Ebola and Marburg viruses are emerging pathogens that cause hemorrhagic fever with high mortality rates in humans and non-human primates. Public concern about these viruses has recently increased owing to a large frequency of virus-related deaths in central Africa (such as the current crisis in Angola) and because these pathogens are considered to be potential bioterrorism agents, with no known cure.
Currently, there are no vaccines or therapies against Ebola or Marburg virus approved for human use. In the new study, Heinz Feldmann, Steve Jones and Thomas Geisbert and colleagues developed vaccines against the two pathogens. The vaccines are based on a recombinant form of the vesicular stomatitis virus expressing either the Ebola or the Marburg virus surface protein. The vaccine is attenuated, meaning that the structure looks like rVSV, but triggers none of the symptoms associated with it, as the coding is contained within the surface protein which in this case has been replaced with either Ebola or Marburg surface protein.
The researchers found that a single injection of either vaccine in macaques produced completely protective immune responses when the corresponding virus was introduced into the macaques systems. Looking for the immune mechanisms that accounted for the protection, the authors found that the Ebola vaccine induced both cellular and antibody-mediated immune responses in all vaccinated monkeys. However, the antibody-mediated response induced by the Marburg vaccine was stronger than the corresponding cellular response. Finally, the scientists found no evidence of Ebola or Marburg viral replication in any of the vaccinated animals.
The data of this study indicate that these vaccine candidates are safe and highly effective in a relevant animal model, highlighting their real potential for use in humans.
Author contact:
Steve Jones (Public Health Agency of Canada, Winnipeg, Canada)
Contactable via: Kelly Keith (communications manager)
Tel: +1 204 7895 0285, E-mail: [email protected]
Tom Geisbert (United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, USA)
Tel: +1 301 619 4803, E-mail: [email protected]
Additional contact for comment on paper:
Sylvain Baize (Institut Pasteur, Lyon, France)
Tel: +33 4 37 28 24 44, E-mail: [email protected]
***Please note: extra resources for this paper will be available on the relevant section of the Nature press site. Please check the site for updates. ***
*******************************************NATURE NEUROSCIENCE ***********************************
(http://www.nature.com/natureneuroscience)
[8] The painful side of empathy
DOI: 10.1038/nn1481
Everyone who watches movies knows that seeing someone get hurt can produce a strong emotional reaction. Empathy for pain in others extends beyond emotions, though, to the control of single muscles, reports a study in the July issue of Nature Neuroscience. Subjects showed decreased excitability in the particular muscle that they saw being pierced by a needle in someone else, suggesting that people may feel other people's pain in an almost literal sense.
Salvatore Aglioti and colleagues used transcranial magnetic stimulation -- used to induce differing electric fields in the brain, without surgery or external electrodes -- to excite the motor control areas of the cortex, while subjects watched a video of a pin being inserted into someone's hand or foot, or into a tomato. The subjects who rated the other person's presumed pain intensity as higher showed a stronger effect on muscle excitability. However, there was no correlation between ratings of the emotional unpleasantness of the other person's pain and the muscle excitability effect. The authors conclude that the social dimension of pain in humans extends even to very basic sensorimotor levels of neural processing.
Author contact:
Salvatore M Aglioti (Universit�� degli studi di Roma "La Sapienza", Rome, Italy)
Tel: +39 6 4991 7601; E-mail: [email protected]
Additional contact for comment on paper:
Chris Frith (University College London, UK)
Tel: +44 171 833 7456; E-mail: [email protected]
Other papers from Nature Neuroscience to be published online at the same time and with the same embargo:
[9] Loss of mammalian Sprouty2 leads to enteric neuronal hyperplasia and esophageal achalasia
DOI: 10.1038/nn1485
[10] PI3 kinase signaling is required for retrieval and extinction of contextual memory
DOI: 10.1038/nn1482
[11] Hebbian LTP in feed-forward inhibitory interneurons and the temporal fidelity of input discrimination
DOI: 10.1038/nn1486
*******************************************NATURE IMMUNOLOGY ************************************
(http://www.nature.com/natureimmunology)
[12] Fueling fire in the gut
DOI: 10.1038/ni1212
Our intestines have specialized cells that promote immune responses to various stimuli in their environment, according to a new report in the July issue of Nature Immunology. This finding could have implications for the development of effective oral vaccines, for which a strong immune response is desired, as well as for the treatment of inflammatory bowel diseases, such as Crohn's disease, for which dampening of inflammation is important. Currently around 600,000 Americans have some form of inflammatory bowel disease every year.
Conventional wisdom suggests that the gut favors a 'mild' local environment because it is necessary for us to live in harmony with a community of beneficial bacteria. However, the gut does respond to harmful bacteria and sometimes to harmless bacteria to cause inflammation. Manjunath and colleagues found that certain cells that produce a molecule called CD70 and reside in a region known as the lamina propria, which is just under the surface of the intestine. These CD70-producing cells are critical for expanding the number of immune T cells during an infection. The cells also help to further equip these T cells with offensive potentials.
Although the precise identity of the CD70-producing cells is still elusive, it is clear that the CD70 molecule is crucial in inducing a heightened immune response. Thus, targeting CD70 and its interacting partner on T cells provides the basis for further investigation into the control of gut immunity.
Author contact:
N. Manjunath (Harvard Medical School, Boston, MA, USA)
Tel: +1 617 278 3240, Email: [email protected]
Additional contact for comments on paper:
Brian L. Kelsall (National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, USA)
Tel: +1 301 496 7473, E-mail: [email protected]
Other papers from Nature Immunology to be published online at the same time and with the same embargo:
[13] The MRE11-RAD50-NBS1 complex accelerates somatic hypermutation and gene conversion of immunoglobulin variable regions
DOI: 10.1038/ni1215
**********************NATURE STRUCTURAL AND MOLECULAR BIOLOGY************************
(http://www.nature.com/natstructmolbiol)
[14] New threat of antimalarial resistance
DOI: 10.1038/nsmb947
Artemisinins are the last line of defense against drug-resistant malaria parasites. They selectively target an important protein in the parasite without affecting the protein's close relative in humans. A study in the July issue of Nature Structural & Molecular Biology now reveals the basis of this selectivity.
Artemisinins selectively block the activity of a calcium-pumping protein in malaria parasites. Sanjeev Krishna and colleagues show that a single amino acid residue in this protein can determine this selectivity. When this amino acid is mutated to the corresponding residue found in the related human protein, the activity of the mutant malarial calcium pump is no longer blocked by artemisinins.
This observation suggests that artemisinin resistance could readily develop because a single mutation in the calcium pump protein is all it would take to produce drug-resistant parasites, pointing to the urgent need to develop robust treatment against malaria.
Author contact:
Sanjeev Krishna (St. George's Hospital Medical School, London, UK)
Tel: +44 208 725 5836, E-mail: [email protected]
Other papers from Nature Structural & Molecular Biology to be published online at the same time and with the same embargo:
[15] Prolyl isomerization as a molecular timer in phage infection
DOI: 10.1038/nsmb946
[16] Conformational regulation of charge recombination reactions in a photosynthetic bacterial reaction center
DOI: 10.1038/nsmb948
[17] TFIIH XPB mutants suggest a unified bacterial-like mechanism for promoter opening but not escape
DOI: 10.1038/nsmb949
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Items from other Nature journals to be published online at the same time and with the same embargo:
NATURE GENETICS (http://www.nature.com/naturegenetics)
[18] Calcium-sensitive potassium channelopathy in human epilepsy and paroxysmal movement disorder
DOI: 10.1038/ng1585
[19] Genomic screening and replication the same data set in family-based association testing
DOI: 10.1038/ng1582
NATURE CELL BIOLOGY (http://www.nature.com/naturecellbiology)
[20] MicroRNA-dependent localization of targeted mRNAs to mammalian P-bodies
DOI: 10.1038/ncb1274
[21] Diego and Prickle regulate Frizzled planar cell polarity signalling by competing for Dishevelled binding
DOI: 10.1038/ncb1271
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Items for immediate release:
NATURE GENETICS (http://www.nature.com/naturegenetics)
***Please note this is the only item on this press release for immediate release. All other items remain embargoed until Sunday 5 June 18:00 London Time (BST)***
[22] TRPC6 is a glomerular slit diaphragm-associated channel required for normal renal function
DOI: 10.1038/ng1592
