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Archive - Mar 20, 2019

Mobile DNA Element Found in Mosquito Parasite (Wolbachia) Has Potential for Infectious Disease Control

Controlling mosquito-borne illnesses, such as Dengue or West Nile virus, has historically been difficult due to a lack of effective vaccines and concerns about the environmental impact of insecticides. Thus, scientists have turned to manipulating Wolbachia, a parasitic bacterium within mosquitoes, as a way to control the reproductive fitness of mosquito populations that transmit human disease. In a new study published on March 5, 2019 in Nature Communications, an international team, including scientists from the Marine Biological Laboratory (MBL) and the University of Chicago, identified a new mobile DNA element in Wolbachia, which may contribute to improved control strategies for mosquito vectors of disease. The open-access article is titled “The Wolbachia Mobilome in Culex pipiens Includes a Putative Plasmid.” Led by former MBL scientists Julie Reveillaud, PhD, of INRA, France, and Sarah Bordenstein of Vanderbilt University (USA), the researchers reconstructed near-complete genomes of Wolbachia isolated from individual ovaries of four Culex pipiens mosquitoes. In the process, the scientists identified a novel plasmid -- a circular piece of DNA that can replicate independently of the chromosomes. Because a plasmid is a mobile DNA element, it can transfer from one cell to another and can have great implications for the fitness and evolution of a microbial species. Mobile genetic elements that can spread through different Wolbachia cells, and thus across a Wolbachia population, hold promise for controlling mosquito populations that may carry disease. "Our data show that this novel plasmid is widespread across natural Wolbachia populations that infect C. pipiens mosquitoes throughout the world, which implies it has an essential role.

Guided by Human “Super Smeller,” Scientists Use Mass Spectrometry to ID Volatile Biomarkers for Parkinson’s Disease; Novel Findings May Enable Development of Noninvasive, Biomarker-Based Test That Will Permit Early Detection of Parkinson’s

Parkinson's disease (PD) is a neurodegenerative disorder that leads to progressive brain cell death and extensive loss of motor function. Despite much research being conducted on this disease, there are no definitive diagnostic tests currently available. Now, researchers report the identification of compounds that make up the signature odor of the disease with the help an individual who can detect PD through smell. They reported their findings on March 20, 2019 in ACS Central Science, published by the American Chemical Society. The open-access article is titled “Discovery of Volatile Biomarkers of Parkinson’s Disease from Sebum.” Ancient physicians, including Hippocrates, Galenus, and Avicenna, used scent as a diagnostic tool, and although olfactory tests are not common in modern medicine, diseases such as diabetes are often associated with a particular smell. However, there has been little evidence to tie scent to neurodegenerative disorders. Enter Joy Milne (photo), a "Super Smeller," a grandmother whose late husband Les was diagnosed with PD in 1986. Milne has an extremely sensitive sense of smell, and this enables her to detect and discriminate odors not normally detected by those of average olfactory ability. Milne can distinguish the unique odor of PD, which she can detect in subjects' sebum long before clinical symptoms appear. Sebrum is a light yellow, waxy, lipid-based biofluid that is secreted by the sebaceous glands and moisturizes and protects the hair and the skin, particularly the skin on the forehead and upper back. Sebum is made up of triglycerides, free fatty acids, wax esters, squalene, cholesterol esters, and cholesterol. Excessive production of sebrum is a known symptom of PD.