— Archaeologists find new evidence of animals being introduced to prehistoric Caribbean — An archaeological research team from North Carolina State University, the University of Washington and University of Florida has found one of the most diverse collections of prehistoric…
— Microscopic worms could hold the key to living life on Mars — The astrophysicist Stephen Hawking believes that if humanity is to survive we will have up sticks and colonise space. But is the human body up to the challenge?…
— Chemical warfare of stealthy silverfish — A co-evolutionary arms race exists between social insects and their parasites. Army ants (Leptogenys distinguenda) share their nests with several parasites such as beetles, snails and…
— Stinky frogs are a treasure trove of antibiotic substances — Some of the nastiest smelling creatures on Earth have skin that produces the greatest known variety of anti-bacterial substances that hold promise for becoming new weapons in the battle…
— Genetic code of first arachnid cracked — An international team of scientists - including Ghent VIB scientists - has succeeded in deciphering the genome of the spider mite. This is also the first known genome of an arachnid.…
— How bats 'hear' objects in their path — By placing real and virtual objects in the flight paths of bats, scientists at the Universities of Bristol and Munich have shed new light on how echolocation works. Their research is…
— Counting cats: The endangered snow leopards of the Himalayas — The elusive snow leopard (Panthera uncia) lives high in the mountains across Central Asia. Despite potentially living across 12 countries the actual numbers of this beautiful large…
— Surprise role of nuclear structure protein in development — Scientists have long held theories about the importance of proteins called B-type lamins in the process of embryonic stem cells replicating and differentiating into different varieties…
— Pregnancy is a drag for bottlenose dolphins — Lumbering around during the final weeks before delivery is tough for any pregnant mum. Most females adjust their movements to compensate for the extreme physical changes that accompany…
Warning lights mark shellfish that aren't safe to eat
Red tides and similar blooms can render some seafood unsafe to eat, though it can be difficult to tell whether a particular batch harbours toxins that cause food poisoning.
A new kind of marker developed by chemists at the University of California, San Diego, and reported in the journal ChemComm makes it easier to see if shellfish are filled with toxin-producing organisms.
Mussels and oysters accumulate single-celled marine creatures called dinoflagellates in their digestive systems as they filter seawater for food. Usually dinoflagellates are harmless, but sometimes they produce dangerous toxins. The trick is figuring out when.
Scientists think symbiotic bacteria that live on the surface of dinoflagellates probably help synthesise the toxins, but no one is sure how. Genetic tools often used to sort out such relationships don't work for dinoflagellates, which have enormous genomes that are not well understood.
So chemistry professor Michael Burkhart's group took a different approach. They set up a system to add a fluorescent tag to an enzyme that makes one kind of toxin, okadaic acid, but with a twist. By handing the tag to a the molecule that turns the enzyme on, they ensured that only those parts of cells that are capable of making the toxin would glow.
Specks glow brightly on the surface of dinoflagellates incubated with both the marker and symbiotic bacteria, and the toxin accumulates in the culture. Those lights go off, and toxin production ceases, if the chemists add antibiotics to the mix.
The new marker proved useful in live mussels as well. Their guts glowed with toxin-producing dinoflagellates even before the poison transferred to the mussel tissue itself.
This technique may could be the basis of an early warning system for aquaculturists and in theory it could lower the risk of shellfish poisoning.
Right now, the method requires a relatively expensive fluroscence microscope to view the tagged cells, but Burkhart's team is optimistic that rapidly developing technology will soon make the tag easy to detect with a handheld device.
Or subscribe for our Newsletter, a free e-mail publication. It is published practically every day.
Plant biologists discover gene that switches on 'essence of male'
New technique used to profile anthrax genome
Researchers identify a process that regulates seed germination
UCR scientists identify stem-cell genes that help form plant organs