The Eukaryotic Tree of Life Expands
Dalhousie University ♦ Published in PNAS, Jan. 4, 2011
Photosynthetic marine organisms carry out roughly half of the primary production on the planet today. Tracing the lineages of these tiny creatures has helped us document eukaryotic evolution and draw conclusions on the events that led to their current distribution and the distribution of the genetic content hidden within them. A new lineage of photosynthetic algae, being referred to as rappemonads, has been discovered by Dr. John Archibald’s lab group in the Department of Biochemistry and Molecular Biology at Dalhousie University. Phylogenetic analysis using operons from plastid ribosomal DNA indicates that this new group is indeed evolutionarily distinct. Furthermore, scientists revealed that the habitat distribution of rappemonads is wide; environmental DNA sequencing in the North Atlantic, North Pacific, and at European fresh water sites suggests an extensive diversity. Although flare-ups of this new species are rare, they are believed to be able to form transient blooms. Quantitative PCR analysis was able to detect large quantities of rappemonads rRNA in the Sargasso Sea. Discoveries of this nature bring to mind the Sorcerer II expedition — launched by Craig Venter in 2004 — where researchers traveled the world’s oceans to discover new microbial species. The field of environmental genomics is in its infancy, and has the potential to help us alleviate some of our environmental issues and elucidate many aspects of biodiversity and evolution.
Novel Vaccine Delivery Formulation Protects Against Respiratory Pathogen Challenge
Institute for Biological Sciences, NRCC ♦ Published in PLoS ONE, Dec. 29, 2011
Mucosal surfaces represent an excellent opportunity for microbial pathogens to invade the body and give rise to infections. Currently many systemic vaccines targeting these pathogens fail to elicit adequate mucosal immunity in the host. It is for these reasons that Dr. Wangxue Chen and his colleagues at the NRCC are developing mucosal vaccines that specifically target these entry points. Creating long lasting and memory boostable immune responses has proven difficult with mucosal vaccines however, and they typically require an adjuvant, or delivery vehicle, to be successful. The team at NRCC has found that intranasal immunization of mice with a cell free extract of Fransicella tularensis has much more pronounced effects when it is paired with archael lipid mucosal vaccine adjuvant and delivery (AMVAD). The technology incorporates cell free extract, from the organism against which immunity is desired, into liposomes which can then be delivered as a vaccine. Mice receiving the AMVAD/extract preparation had lower pathogen burden in the lungs and spleen, longer mean time to death, and significantly greater overall survival than mice that received just the cell free extract or naive mice receiving no vaccination.
Oxidative Stress of Surrogate Tissues Mirrors that of the Prostate
McMaster University ♦ University of Toronto ♦ Published in PLoS ONE, Dec. 28, 2011
Researchers believe that surrogate androgen regulated tissues from the same host can be used to determine the oxidative stress (OS) status of the prostate. Androgens have long been known to drive the formation of prostate cancer. Oxidative stress is regulated by androgens, so reducing OS is a key target in the prevention of prostate cancer. Using a mouse model researchers show that the level of prostatic OS is correlated with the OS of Dermal Papillary Cells, a cell type found in hair follicles, and also the salivary glands – two exocrine glands that express the androgen receptor and are morphologically similar to the prostate. Determining the OS status of the prostate and patient response to prevention strategies directly, would require taking a biopsy sample from the prostate itself. Thus, the findings of Dr. Jehonathan Pinthus and his team at McMaster University could have great implications for the non-invasive and indirect evaluation of prostate OS status and patient response to prevention strategies.