Natures wonders: microbiome influence an IM? (Introduction)

by David Turell , Tuesday, December 16, 2014, 14:56 (3628 days ago) @ David Turell

Another possibility for an IM mechanism is microbiome influence on the host animal. It is now well recognized that beneficial bacteria help horse digestion, influence human digestion, and that we pack pounds of 'friendly, but foreign' bugs in our bodies. This study looks at the influence of bacteria in insects:-http://www.the-scientist.com//?articles.view/articleNo/41668/title/Communicating-Across-Kingdoms-/-"Wolbachia bacteria live inside the cells of other species and can strongly influence the lives of their hosts. These bacteria manipulate host reproductive biology to increase their own transmission. Wolbachia have been documented in more than 40 percent of terrestrial arthropods.-"Previous studies have shown that Wolbachia can regulate certain microRNAs (miRNAs) in the host Aedes aegypti, resulting in increased production of certain enzymes and decreased production of others, both in favor Wolbachia persistence. Using deep sequencing, Asgari's team found that two miRNAs, WsnRNA-46 and WsnRNA-49, were highly expressed in Wolbachia-infected mosquitoes—and especially in cells where the bacteria dwelled. WsnRNA-46 and WsnRNA-49 are both about 30 nucleotides long, have stem-loop structures, and are far from each other on the genome, governed by independent promoters.-"But Bryan Cullen, a molecular geneticist at Duke University, is skeptical of the role of Wolbachia miRNAs in host gene regulation. “This argument that miRNAs increase target gene expression—not repress—has no precedent,” he told The Scientist in an e-mail.-“The study is very intriguing, and opens up new mechanisms by which Wolbachia and other bacteria could manipulate or more generally interact with their hosts,” said evolutionary geneticist John Werren from the University of Rochester in New York. “I am not sure that I would call this ‘communication,' however,” he added, as the authors have in their paper."