Posts Tagged: Graduate School of Biosphere Science

Promoting parasites: Researchers’ quest to identify freshwater fish parasites in Japan

Promoting parasites: Researchers’ quest to identify freshwater fish parasites in Japan

  Hiroshima University scientists have identified a new species of parasite infecting an invasive freshwater fish on the subtropical island of Okinawa, Japan. The results are part of a project to find parasites that have arrived in Japan with their non-native hosts and understand the role of parasites in natural ecosystems.  Tracking parasites can be one scientific method to monitor ecosystem health and attempt to conserve biodiversity. The project began in 2012 when one of the researchers was trying to fill some of his free time.  Masato Nitta, now a second-year PhD student at Hiroshima University, recognized some invasive fish in the stream that runs through the campus of the… Read more

Well-wrapped feces allow lobsters to eat jellyfish stingers without injury

Well-wrapped feces allow lobsters to eat jellyfish stingers without injury

Results advance efforts for sustainable lobster aquaculture Lobsters eat jellyfish without harm from the venomous stingers due to a series of physical adaptations.  Researchers from Hiroshima University examined lobster feces to discover that lobsters surround their servings of jellyfish in protective membranes that prevent the stingers from injecting their venom.  The results are vial for aquaculture efforts to sustainably farm lobsters for diners around the world. Lobsters grow for years before becoming a red-shelled main meal.  In their early life stages, the larvae of slipper and spiny lobsters are nearly transparent and about the size of an adult’s thumb nail.  Lobster larvae ride around the ocean on the bodies of… Read more

New prebiotic identified in fermented Japanese vegetable

New prebiotic identified in fermented Japanese vegetable

Enzyme improves colon health in rats An enzyme produced by fermenting a vegetable common in Japanese cuisine may be responsible for increasing the amount of at least one beneficial bacterium associated with healthy colons in a study using rats.  The results of this prebiotic research study will be presented at the International Conference on Nutraceuticals and Nutrition Supplements in July 2016 by Norihisa Kato, Ph.D., and at the International Nutrition and Diagnostic Conference in October 2016 by doctoral student Yongshou Yang, both from Hiroshima University. The vegetable, called burdock root in English and gobo in Japanese, has a minimal positive effect on colon health when eaten raw or cooked.  Like… Read more

How females store sperm: fertility study in chickens examines fatty acids

How females store sperm: fertility study in chickens examines fatty acids

The science of breeding chickens has revealed part of the mystery of how certain female animals are able to store sperm long-term.  Droplets of fat transferred from female cells to sperm cells may contribute to keeping sperm alive. Females of some types of insects, reptiles, and birds can store sperm from multiple males within specialized sperm storage areas of their reproductive tracts.  Different animals can store sperm for days or years.  Stored sperm can fertilize multiple eggs over time, meaning females do not need to mate again to fertilize additional eggs. “Farmers may be able to more successfully breed their flocks if we could understand how the sperm stays viable… Read more

A microbial metabolite of linoleic acid ameliorates intestinal inflammation

A microbial metabolite of linoleic acid ameliorates intestinal inflammation

Inflammatory bowel diseases (IBDs), including Crohn disease and ulcerative colitis, are hard to completely cure. Globally, IBDs affect more than 4 million people, today. However, Professor Soichi Tanabe (Graduate School of Biosphere Science, Hiroshima University) and his collaborators have demonstrated that 10-hydroxy-cis-12-octadecenoic acid (HYA), a gut microbial metabolite of linoleic acid, has a suppressive effect on intestinal inflammation. HYA is expected to be practically applied as a functional food. The results of this group’s research were published in The Journal of Biological Chemistry as “A gut microbial metabolite of linoleic acid, 10-hydroxy-cis-12-octadecenoic acid, ameliorates intestinal epithelial barrier impairment partially via GPR40-MEK-ERK pathway” DOI: 10.1074/jbc.M114.610733. IBD patients characteristically demonstrate increased expression of tumor… Read more

What are the mechanisms of zooxanthella expulsion from coral?

What are the mechanisms of zooxanthella expulsion from coral?

Coral bleaching, which often results in the mass mortality of corals and in the collapse of coral reef ecosystems, has become an important issue around the world, with the number of coral reefs decreasing annually. Associate Professor Kazuhiko Koike and Ms. Lisa Fujise of the Graduate School of Biosphere Science at Hiroshima University and their collaborators have proposed mechanisms that might cause coral bleaching and damage. This research group demonstrated that corals more actively digest and expel damaged symbiotic zooxanthellae under conditions of thermal stress, and that this is likely to be a mechanism that helps corals to cope with environmental change. On the other hand, if the stressful conditions… Read more