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July 9, 1998
Squid Attract Scientists to Woods Hole
Researchers at the Marine Biological Laboratory announce the successful culture of new biomedical model
Woods Hole, MA - In April tens of thousands of Loligo pealei, the Woods Hole squid, will begin their migration to the waters off Cape Cod. They come to the shores of Woods Hole each spring like clockwork, like the swallows to San Juan Capistrano.
Soon the waters off Woods Hole will teem with squid and fishing boats. And soon the laboratories of the Marine Biological Laboratory's Whitman building will teem with scores neurobiologists who, while the squid are running nearby, make their own pilgrimage to Woods Hole. Researchers come to the MBL each summer from universities and medical schools as close as New Haven and Cambridge and as far away as Germany and Argentina to spend night and day in the laboratory, using the Woods Hole squid as a model for understanding basic neurobiological processes.
For sixty years the Woods Hole squid's giant nerve cell (axon) has helped scientists answer many basic questions about how electrical charges are transmitted from nerve cell to nerve cell; how nutrients and other important particles are transported from one end of a cell to another; and how certain cells maintain the body's pH level. This basic research on the squid has provided researchers and clinicians with vital information that has helped them develop a better understanding of such debilitating human diseases as cancer, Alzheimer's Disease, and kidney disease.
Now there's a new squid in town, and it promises to be yet another important biomedical model, says Roger Hanlon, director of the MBL's Marine Resources Center. For the first time in the continental U.S., MRC scientists have successfully cultured this squid, a Hawaiian species called Euprymna scolopes, throughout its life cycle, paving the way for its use as a model research system.
What interests scientists most about Euprymna is not its nerve cell but the animal's unique symbiosis with the luminous marine bacterium Vibrio fischeri. Vibrio enjoys a mutually beneficial relationship with Euprymna, living within the large light organ found in the squid's mantle cavity. Although scientists are still mystified by the squid-bacterium relationship, they do know that Vibrio produces 1000 times more light when it exists within the squid's light organ than it does when cultured outside of the organism. Scientists believe that the light produced by Vibrio within the light organ may help disguise the squid, through a light-diffusing behavior known as counterillumination, from predators swimming below them. How the bacterium benefits from its relationship with the squid remains unclear, although studies show that this symbiosis does have an effect on Vibrio's growth rate and life cycle.
Scientists, including Paul Dunlap of the Woods Hole Oceanographic Institution and Margaret McFall-Ngai and Ned Ruby of the University of Southern California, believe that understanding how this curious symbiosis works will have a biomedical benefit for human health as well. Although the species of bacterium living within Euprymna is harmless, many species of Vibrio are not. In fact, some species of Vibrio, including the one that causes cholera and the species that causes paralytic shellfish poisoning, can be deadly. Understanding how the Euprymna/Vibrio symbiosis works will provide scientists, including immunologists, with information about how all bacteria and other microbes—whether harmless or pathogenic—are able to recognize and colonize specific tissues in its host.
Scientists' ability to develop this model has been enhanced considerably, thanks to the Marine Biological Laboratory's recent success in culturing Euprymna from egg to egg. Now investigators can study both the squid and the bacterium in culture separately to learn how each organism functions independently of the other, as well as how they live successfully together as a symbiotic pair. And, again thanks to the MBL's ability to culture Euprymna, scientists can come to Woods Hole to do so at any time of year.
The Marine Biological Laboratory is an independent scientific institution, founded in 1888, that undertakes the highest level of creative research and education in biology, including the biomedical and environmental sciences.
Visuals: Woods Hole and the Marine Biological Laboratory are extremely photogenic, especially during the late spring and summer. Visuals include collecting squid offshore on the RV Gemma, a squid axon dissection in the laboratory, culturing and holding squid—both Loligo and Euprymna—in the 32,000-square-foot state-of-the-art Marine Resources Center, and scores of scientists from a wide variety of institutions world-wide working on a number of different marine models (availability of specific scientists depends on time of year).
A variety of other stories are also available at the Marine Biological Laboratory this summer, including cell communication and cancer (using sea urchins and surf clams as models); looking for anti-tumor drugs in the world of marine microbes; and training the world's best and brightest biologists through our world-class courses in physiology, embryology, neurobiology, and parasitology, and microbiology. |
