Rice plants defend against the agriculturally important bacterial pathogen Xanthomonas oryzae (Xoo) with XA21— the first characterized of more than 350 predicted rice immune receptors, according to Pamela Ronald at the University of California, Davis (UCD). Last year, she and her collaborators identified three Xoo rax genes required for activating XA21-mediated immunity in the plants that this pathogen infects. These genes suggest that tyrosine sulfation plays “a key functional role in the process,” they say, calling the newly identified tyrosine-sulfated protein that they encode “RaxX.” Details appeared in 24 July 2015 in Science Advances (2015:1:e 1500245).
The host cell that engulfed the alpha-proteobacterial ancestor of mitochondria billions of years ago was complex and full of pathways and processes from diverse other bacteria, according to Alexandros Pittis and Toni Gabaldon from the Centre for Genomic Regulation in Barcelona, Spain. It apparently partnered late, as “mito-late,” during eukaryogenesis, and subsequently shed many genes en route to modern times. Details about mito-late appeared 3 March 2016 in Nature (doi:10.1038/nature16941), while details about mitochondrial gene shedding appeared 24 February 2016 in Cell Systems (doi.org/10.1016/j.cels.2016.01.013).
Although most introductory biology courses offered in high school or college contain at least one session that examines microscopic organisms, Nicholas Money feels that these small organisms deserve much more attention and research support. So he passionately and expertly goes on to demonstrate that there are all sorts of fascinating and weird microbes in the earth, in the water, in the air, and even in and on our bodies. They don't just exist but have essential roles interacting intimately with each other, their environment, and the larger hosts that they inhabit. Over time these small organisms have even begun to share some or all of their genetic information, sometimes integrating their genetic information into the DNA of the host or existing as organelles within the host cell.
How critical is a postdoc if i want to teach at a primarily undergraduate or 2-year institution?
Low-molecular-weight compounds that trigger innate immunity response genes might serve as broad-spectrum antiviral agents, acting through the innate immune system to suppress a wide range of RNA viruses, including influenza A and hepatitis C, as well as the emerging dengue, Ebola, Lassa, Nipah, and West Nile viruses, according to Michael Gale, Jr., of the University of Washington, Seattle, and his collaborators. The research appeared 16 December 2015 in the Journal of Virology (doi:10.1128/JVI.02202–15).
Gas plasmas consisting of ionized air at ambient temperature can disinfect contact lenses in 2 minutes, according to Michael G. Kong of Old Dominion University in Norfolk, Va., and his collaborators at several universities in the United Kingdom. The procedure is effective against bacteria, spores, fungi, and even cysts of Acanthamoeba protozoans, which are notoriously difficult to kill or remove from such surfaces. Thus, treating lenses with such plasmas will likely be effective in preventing keratitis, a serious inflammation of the cornea that can lead to blindness. Details appeared 18 March 2016 in Applied and Environmental Microbiology (doi:10.1128/AEM.03863–15).
The gut microbiota in mice consumes glycine, one of three amino acids needed by host animals to make the powerful antioxidant peptide glutathione, according to Adil Mardinoglu at the Royal Institute of Technology in Stockholm and Chalmers University of Technology, Gothenburg, both in Sweden, and his collaborators in Sweden and Denmark. He calls this example of the gut microbiota exerting partial control over this host metabolic pathway “surprising,” and suggests that “imbalances in the composition of bacteria [within the microbiota] may lead to the progression of chronic diseases.” Details appeared 16 October 2015 in Molecular Systems Biology (doi:10.15252/msb.20156487).
The 2016 Nobel Prize in Physiology or Medicine, about $936,000 this year, recognizes Yoshinori Ohsumi of Japan for his efforts to understand autophagy, a fundamental process for degrading and recycling cellular components, research that he began by studying yeast. Separately, among the 2016 MacArthur Foundation Fellows, who receive $625,000 “genius awards,” are microbiologist Dianne Newman, who studies bacteria that played roles in shaping the Earth as well as in modern biomedical contexts; geobiologist Victoria Orphan, whose focus is on microbial communities in extreme environments; and physical biologist Manu Prakash, who invented several devices that can be used for diagnostic work in microbiology. Also noteworthy, the 2016 LaskerDeBakey Clinical Medical Research Award is shared by three scientists whose research on hepatitis C virus (HCV) led to development of drugs for treating HCV infections.
Distributed cell division counting (DCDC), an analytic tool developed using synthetic biology, enables researchers to tag cells of Escherichia coli, follow their passage through the gastrointestinal (GI) tract of a mouse—or, presumably, a human—as they divide, and determine bacterial cell population dynamics within this otherwise inaccessible anatomic system, according to Cameron Myhrvold, Pamela Silver, and their collaborators at Harvard Medical School in Boston, Mass. This analytic approach can be adapted to “study microbial growth during infection, gut dysbiosis, antibiotic therapy, or other situations relevant to human health,” they note. Details appeared 30 November 2015 in Nature Communications (doi:10.1038/ncomms10039).
The grinding of glacial ice along silicate rocks releases enough hydrogen gas to support the energy needs of some microbial ecosystems, all at 0°C, including those containing Thiobacillus, Rhodoferax, Geobacter, and a diversity of methanogens, according to Jon Telling at the University of Bristol in the United Kingdom (UK) and his collaborators there and in the United States. The research has important implications for subglacial environments that acted as refuges, enabling microorganisms to survive during the Neoproterozoic glaciations, also called Snowball Earth. Details appeared 8 November 2015 in Nature Geoscience (doi.org/10.1038/ngeo2533).
Epithelial cells lining the gastrointestinal tracts of mice secrete microRNA molecules that can enter and switch on genes that alter the growth of certain types of bacteria in the gut, according to Howard Weiner and Shirong Liu at Brigham and Women's Hospital in Boston, Mass., and their collaborators. “It's a very basic finding, but it opens up an area of interaction between microRNAs and the gut microbiome that hasn't been known before,” Weiner says. “Our findings highlight microRNAs as a strategy for manipulation of the microbiome that may affect the health of the host.” Details appeared 13 January 2016 in Cell Host & Microbe (doi.org/10.1016/j.chom.2015.12.005).
Warmer temperatures and elevated carbon dioxide significantly alter soil microbiome structure and functions, according to Jizhong Zhou and Maggie Yuan at the University of Oklahoma, Norman, and collaborators at several institutions in the United States and China. In looking at microbial communities in active layers of Alaskan tundra, these researchers say those communities respond to increased warmth by releasing more carbon than they trap. Separately, in wetlands, global warming and higher levels of carbon dioxide induce changes in the soil microbiomes, fostering “an unusual biogeochemical profile,” according to Felix Beulig and Kirsten Kusel of Friedrich Schiller University Jena in Jena, Germany, and their collaborators.
Global phytoplankton declined significantly during a recent 15-year period—falling more than 1% per year from 1998 to 2012, according to Cecile S. Rousseaux and Watson W. Gregg of the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center in Greenbelt, Md. This loss will reduce the carbon dioxide that these microorganisms take from the atmosphere, they note. Details appeared 16 October 2015 in Global Biogeochemical Cycles (doi:10.1002/2015GB005139).
A genetically modified virus, suitably equipped with properly ordered light-harvesting molecules, can markedly enhance the efficiency with which that energy can be transported, according to Angela M. Belcher of the Massachusetts Institute of Technology in Cambridge, Mass., Petra F. Scudo from Istituto eni Donegani in Novara, Italy, and their collaborators. This research not only helps to elucidate the physics governing light collection, but also might lead to designing improved solar cells as well as diagnostic devices, they note. Details appeared 12 October 2015 in Nature Materials (doi.org/10.1038/nmat4448).
The Journal Impact Factor (JIF) is like the weather: everyone talks about it, everyone complains about it, and everyone feels incapable of changing it. Indeed, the scientific community has been held hostage of this measure of impact for a long time, which erroneously became the one and only simple metric to evaluate the impact of a single publication, the prestige of a journal, or the relevance of an individual scientist.
What does a backward look at the end-Cretaceous mass extinction 66 million years ago have in common with space-based instruments that detect photosynthetic pigments of algal blooms? In both cases, the findings suggest that environmental conditions are critical for enabling toxic or nontoxic algal blooms to proliferate—and, more dramatically, help to explain what can cause ecosystems to collapse.
The recent revelation of the shipment of γ irradiation-inactivated Bacillus anthracis spore reference materials containing a small number of live spores (Department of Defense [DoD] Laboratory Review. DoD Launches Review of Lab Procedures Involving Anthrax. http://www.defense.gov/news/newsarticle.aspx?id=128939, May 29, 2015) has raised concerns about the safety and security of these materials and doubts on the validity of the protocols and procedures used to prepare these materials. Such inactivated spore materials have historically fulfilled critical needs: as positive controls in assays used to detect these pathogens in suspected samples (live agents cannot be shipped and used in field settings), and are also used in improvement of currently deployed detection methods or development of new methods/platforms for detection of these agents; in other words, to develop and validate detection assays, and for quality assurance activities such as proficiency testing. The committee for comprehensive review of DoD Laboratory procedures, processes, and protocols associated with inactivating B. anthracis spores has found inherent deficiencies in protocols in three phases in the production of inactive spores that could lead to nonsterile products: (1) radiation dosing, (2) viability testing, and (3) aseptic operations (contamination prevention). These deficiencies and other factors contributed to the establishment of protocols that do not completely or permanently sterilize these samples (http://archive.defense.gov/home/features/2015/0615_lab-stats/docs/Review-Committee-Report-Final.pdf, July 13, 2015). The review committee made a number of recommendations, including initiating studies to understand the science of irradiating spores and establishment of standardized protocols across the labs engaged in inactivated spore production. In addition, a clear understanding of the nature of the surviving spores would aid in understanding the phase(s) in which the failure occurred and fixing the problem. Here we consider a few hypotheses.
