Paralytic shellfish toxins cause mutation that allows clams to accumulate 100 times more toxin

Exposure to toxins that cause paralytic shellfish poisoning can result in a mutation that makes clams much more resistant to the toxin than other clams, making them more dangerous to humans, according to a study published this week in the journal Nature. Paralytic shellfish toxins (PSTs) are produced by algae that appear in certain coastal areas in the United States in an event known as an algal bloom, commonly called a "red tide." People who eat clams exposed to the PSTs can suffer the paralytic effects of the toxins, and there is no cure for the poisoning.

Researchers found that softshell clams in areas frequently affected by harmful algal blooms are more resistant to PSTs than clams from other areas. They knew from earlier work that the toxins block the function of the sodium ion channel, a molecular switch that generates the nerve impulse and therefore is vital to neural and muscular activity. What they did not know was why some clams were more resistant than others.

The collaborative team of scientists from Washington, Maine, and Nova Scotia determined that the toxins cause a small mutation that prevents them from binding to the sodium ion channels in the clam's nerve tissue. Instead of binding to the ion channels and causing paralysis and later death, the toxins build up in the clam, accumulating about 100 times more toxin than in clams without the mutation. The resistance allows them to continue feeding during the harmful algal bloom and accumulate levels of toxins that increase risk of paralytic shellfish poisoning in humans.

Scientists and public health officials knew that clams carrying the toxins could survive after an algal bloom, which is why clams are tested well after a "red tide" event to reduce the risk of poisoning in humans. But no one knew until now why the clams were accumulating the toxins.

"It is quite surprising that the toxins could serve as selective agents for a mutation in the sodium ion channel, and that the mutation

Contact: Justin Reedy
University of Washington

Page: 1 2

Related biology news :

1. Overfishing large sharks impacts entire marine ecosystem, shrinks shellfish supply
2. Still shellfish after 425 million years: Clam-like creature preserved perfectly in ancient fossil
3. Mutation in clams protects against paralytic shellfish poisoning but raises human health risk
4. Scripps research scientists: Compounds show significant promise against potential bioweapon toxins
5. Red tide toxins leave beachgoers breathless
6. Study of toxins in Houston air warrants new standards
7. A new understanding of how cells defend themselves against bacterial pore-forming toxins
8. Environmental toxins may cause bodys defenses to worsen lung disease
9. Water filtration technique removes dangerous freshwater algae toxins
10. Patent awarded for LSUHSC-developed peptide that blocks lethal toxins of anthrax
11. Yale researchers find environmental toxins disruptive to hearing in mammals

Post Your Comments:

(Date:7/2/2020)... ... July 01, 2020 , ... AltruBio Inc. http://www.altrubio.com , ... biologic for the treatment of steroid-refractory acute graft-versus-host disease (SR-aGVHD), at European Hematology ... Martin of the Fred Hutchinson Cancer Research Center, this single-arm, open-label Phase 1 ...
(Date:6/28/2020)... ... June 25, 2020 , ... ... today announced that it has entered into a multi-year contract with Merus ... support their translational and clinical research strategy to discover and develop ground-breaking ...
(Date:6/23/2020)... ... June 23, 2020 , ... ... healthcare, and Renovagen Ltd, a UK supplier and manufacturer of innovative portable renewable ... testing operations in the fight against the COVID-19 pandemic in Zambia. , One ...
Breaking Biology News(10 mins):
(Date:7/31/2020)... , ... July 29, 2020 , ... eSource has long ... This webinar will cover the history of eSource, the reasons it did not take ... to wearables, to site source, the industry is moving towards capturing data electronically for ...
(Date:7/18/2020)... ... ... After research model surgery and catheter implantation, the long journey of catheter maintenance and ... successful study, while protecting and accessing the catheter or device post-surgery is often undervalued ... Envigo in a live webinar on Wednesday, August 5, 2020 at ...
(Date:7/10/2020)... ... July 08, 2020 , ... Bode Technology, ... of laboratory operations through its COVID-19 testing service, Bode-CARES . Bode-CARES combines ... Bode-CARES provides a turnkey solution that includes a comprehensive collection and ...
(Date:7/7/2020)... ... , ... R3 International is now offering stem cell therapy for Alzheimers dementia ... on the patient's condition, treatment may be offered IV, intrathecal or with a combination. ... Alzheimers dementia, and the incidence continues to increase as individuals live longer. There is ...
Breaking Biology Technology:
Cached News: