scanning electron microscope Viola venice Swallowing cryptophytes’ favorite prey (Photo courtesy of Vince Lovko, VIMS),
In James Fraser’s classic 1962 “Natural Drifting – The Story of Ocean Plankton” The author points out that “poisonous Dinoflagellates live in British waters: it is Gymnodinium and is cultured at Plymouth Marine Biological Station. The authors refer to the work of BC Abbott and D. Ballantine, who described the partial purification and characterization of toxins from . Gymnodinium and concluded that the mode of action is “due to membrane depolarization.” The new footnotes are as follows:“The conclusions of this paper are necessarily preliminary and need to be verified with purified toxin samples.”
We provide this validation in the current manuscript, where its structure, mode of action, and sterol specificity are presented.
Researchers led by Professor Allen R. Place of the University of Maryland Center for Environmental Science have discovered important details about this potent toxin first discovered in the 1950s. This toxin is called steroid hemolysin and is produced by Cardinella venezia (formerly known as Gymnodinium)Microscopic algae notorious for killing large numbers of fish. The study, published in the journal Scientific Reports, examined how steroidolysins create harmful pores, or openings, in cell membranes, solving a mystery that has persisted for more than seven decades.
Cardinella veneziaOriginally collected near Plymouth Bay, England in the late 1940s, it is known for its deadly effects. The researchers studied live cultures of the species that had been kept at a Plymouth laboratory for decades. They discovered two poisonous substances, abotoxins and chloroabotoxins, which belong to a group of chemicals called carrotoxins. These are natural toxins that damage cells by targeting specific molecules. The researchers showed that these toxins caused gill damage in fish larvae, consistent with symptoms observed in experiments in the early 1950s. “Our results confirm that the toxin described by Abbott and Ballantine in 1957 is indeed a carrotoxin homologue,” said Professor Place, who emphasized the enduring importance of long-term culture preservation.
The study breaks new ground by showing how sterolysins specifically target sterols, fat molecules found in cell membranes that help maintain their structure. This targeting allows the steroidolysin to punch holes in the membrane, disrupting its function. Using modern methods such as surface plasmon resonance (a technique that measures molecular interactions) and artificial membranes (laboratory-created models of natural cellular barriers), the team showed how toxins bind tightly to these molecules and cause damage. This supports the early view in 1957 that toxins disrupt cell function by damaging cell membranes. As Professor Price explains, “The strength of the steroidolysin’s binding to these membrane molecules ensures its effectiveness, making it a key factor in the toxin’s lethal effect.”
Further experiments revealed how these toxic pores in the membrane behave. Professor Place’s team found that steroidolysins do not cause harm to those who produce them. Viola venicebecause it cannot act on specific sterols in the organism’s own cells. This self-preservation is a clever natural defense that shows how the species avoids poisoning itself while using the toxins to attack other species in the environment.
In addition to providing answers to long-standing questions, this research offers potential benefits to medicine and science. The toxin’s ability to target cells rich in the appropriate sterols could inspire new treatments or technologies to fight certain forms of cancer. It also highlights the value of revisiting earlier studies using today’s advanced tools to confirm theories and expand our understanding.
Summarizing their work, Professor Place and colleagues explain how the toxin’s unique properties make it a model for studying other toxins that damage cell membranes, the protective barrier around cells. By combining historical knowledge with state-of-the-art science, they paint a complete picture by linking past discoveries to current advances. Carotinella Poisonous abilities.
Journal reference
Place, AR, Ramos-Franco, J., Waters, AL, Peng, J., & Hamann, MT (2024). “Sterolysins from 1950s cultures of Karlodinium veneficum (aka Gymnodinium veneficum Ballantine) form lethal sterol-dependent membrane pores.” Scientific Reports, 14, 17998.
About the author
Professor Alan Plath is a distinguished scientist and educator known for his contributions to marine biology and toxicology. Holds a Ph.D. from Johns Hopkins University, where he is a professor at the Institute of Marine and Environmental Technology (IMET) and serves as director of the Molecular and Chemistry Core Facility. Throughout his extensive career, Professor Press has worked to understand the molecular mechanisms of harmful algal blooms, particularly the toxins produced by dinoflagellates such as Carodina. His research has revealed groundbreaking insights into the structure and function of carrotoxins, compounds with potential biomedical applications.
In addition to research, Professor Place is an advocate for education, contributing to the BioQUEST program to enhance undergraduate biology learning. Recognized for his leadership, he has chaired major scientific conferences and received multiple awards, including the UMCES Presidential Award for Excellence in the Application of Science. Professor Price continues to explore the ecological and medical impacts of marine toxins.
