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Hopkins Marine Station has 100-year legacy
STANFORD -- The establishment of Hopkins Marine Station in 1892 was forged by two historic developments - one widely known, the other little noticed.
The celebrated event was the meeting of two worlds, Europe and the Americas, in 1492. The meeting triggered a spate of biological exploration that continues today, and has yielded such biological riches as domesticated corn, potatoes and tomatoes.
The less well known development was the revolutionary teaching of Louis Agassiz of Harvard University, who in 1873 irrevocably altered American biology by emphasizing the study of nature.
One of Agassiz's first students was David Starr Jordan, the first president of Stanford University. When he came to Stanford, Jordan wanted the university to have a school dedicated to the intensive study of marine organisms, similar to a school that Agassiz had established on an island off Cape Cod. Supporters for the venture quickly were found, and land provided in Pacific Grove on the Monterey Peninsula.
From the beginning, important research was done at Hopkins. One of its most famous early visitors was Jacques Loeb, who worked in the seaside laboratory in the winter of 1900. While at Hopkins he completed the work, begun that summer at Woods Hole, that led to a classic study of parthenogenesis, the ability to activate eggs artificially to begin development without sperm.
Twenty years after its founding, the station was so popular that it outgrew its original site. Through a land swap with the University of California-Berkeley, the station moved to its current site on China Point in 1917 and a new, larger building was constructed.
The station faculty at that time included scientists engaged in studies of hydrography and oceanography, led by Tage Skogsberg, and embryology, led by Harold Heath. The two scientists personified the two major areas of biological study at Hopkins, both then and now. One area (studied by Skogsberg) is the biology of marine organisms, which focuses on questions of classic marine biology. The other (studied by Heath) is the use of marine organisms as a model to learn about biological phenomena in general.
In the 1960s, under the directorship of John Phillips, Hopkins researchers conducted major studies on marine pollution in Monterey Bay. In the 1990s, with the leadership of current director Dennis Powers, the station has begun to apply the modern techniques of molecular biology and biotechnology to fundamental questions about marine organisms and their environment.
CURRENT HOPKINS FACULTY
Barbara A. Block, Assistant Professor
Ecological and Cellular Physiology, Molecular Biology, Biochemistry
Block, co-director of the Tuna Research and Conservation Center (TRCC), is an expert on the physiology of tunas and two closely related species, marlins and swordfish. She and her students work closely with the scientists and animal husbandry experts of the Monterey Bay Aquarium. Tunas are among the world's few warm- blooded fish. By comparing them with their cold-blooded cousin, the bonito, Block's work is providing new insights into the origins of warm-bloodedness. Studies of the "brain heater" - a muscle that generates heat instead of strength - in marlins and swordfish may help explain some types of human disease. Her studies of tissue samples from marlins and swordfish from many oceans led to DNA analyses that showed that marlins developed as two distinct populations in the Atlantic and Pacific, while swordfish roam both oceans - information that could influence international treaties to protect these populations of fish from depletion.
Mark W. Denny, Associate Professor Biomechanics
Denny looks at the way in which intertidal organisms are designed and engineered. On the one hand, he is interested in figuring out the underlying factors that led to the ways in which mussels, crabs and kelp are designed. At the same time he keeps his eyes peeled for new solutions to basic engineering problems that nature has evolved. Wave-swept shores are an ideal place to conduct research of this type because, next to flight, they place the strictest constraints on how organisms are designed. Denny's studies of limpets and mussels have determined how much wave pounding they can withstand. Using basic information on the average size of waves in an area, Denny can calculate what fraction of mussel beds will be ripped out in a given year, a figure that is very important for scientists who are studying the community structure of intertidal communities. He also is studying the way that waves interact with kelp in an attempt to understand how these flexible and seemingly fragile plants survive.
David Epel, Professor Cell and Developmental Biology
The sea is a hostile environment. Reproduction there is no easy task. Epel studies both the critical early events of fertilization and the methods that marine animals use to protect themselves from toxic materials. Epel's investigations of fertilization using sea urchins have added important new understanding of how cell division is triggered and how the development process is initiated within the egg. His group also studies the means by which both egg and sperm remain dormant under most conditions and what turns on their metabolisms to enable fertilization. Sperm only become motile when they are released into the environment, while the egg only turns on its biosynthetic machinery upon contact with a sperm. This work is proving applicable to the regulation of human fertility. Another research area is the biology of fertilization in the marine environment: There is much information about fertilization in the test tube, but little about how it occurs in nature. In particular, how do pollution and other human intrusions affect embryo development in the ocean? Using marine worms, Epel also is studying mechanisms that organisms use to physically expel toxic materials. Although this is an organism's first line of defense, it has not been studied nearly as extensively as the immune system and other defensive systems that organisms employ for this purpose.
William F. Gilly, Associate Professor
Neurobiology, Cell Biology, Behavior
Understanding how individual nerve cells control sophisticated behaviors is the goal of Gilly's research. He approaches this problem by studying the manner in which the nervous systems of newly hatched squid grow in complexity as the animals respond to their environment. More specifically, he measures these changes in special giant nerve cells that are active when squid flee from predators using jet propulsion. Such responses are controlled by the way in which the squid's neurons transmit information in the form of electrical impulses. The electrical characteristics of the nerve cells, specifically their excitability, are strongly influenced by the common sodium and potassium ions that flow into and out of the cells through special protein gates, called channels. In the brains of mammals, there are probably hundreds of different kinds of channels located in tiny nerve cells. The giant neurons of the squid are much simpler, however, with only one or two types of sodium and potassium channels. Gilly's students have developed several methods to map different types of squid channel proteins and are exploring how these maps are established. They also have discovered that the giant neurons involved in escape responses also play a role in prey capture: The neurons of baby squid raised exclusively on slow, easy-to-catch prey fail to develop normal excitation patterns. As a result, not only do the squid have trouble catching faster prey but they also respond poorly to disturbing stimuli. Determining the molecular mechanisms that cause these changes in excitation patterns is a major focus of Gilly's work.
R. Paul Levine, Research Professor Biochemistry and Molecular Biology
In one project, Levine is shooting Chinook salmon cells with microscopic gold particles. The purpose is to determine if particle bombardment can be used to immunize the salmon against bacterial kidney disease that has decimated a number of different fish populations, including the Chinook salmon in the Sacramento River. The gold particles first are covered with circular strands of DNA, called plasmids, that carry genes that encode bacterial proteins. Then they are shot into the fish cells. The purpose is to generate antibodies and other cellular protective responses against the bacteria involved. So far, Levine has determined that one of the injected bacterial genes has been expressed in the fish cells. Next, he and his students must ascertain whether the process triggers an immune response. In a second, related area of research, Levine is studying the symbiosis between sea anemones and algae. The microscopic green plants live between the cells of the anemone and feed on chemicals that the anemone provides. In return, they produce other chemicals by photosynthesis that the anemone cannot provide for itself. Most information about such relationships is limited to the symbiosis of nitrogen-fixing bacteria and their host plants. Levine's efforts center on identifying the genes and gene products involved in initiating, maintaining and causing this symbiosis to break down. So far, the researchers have identified a number of genes and gene products that appear to be associated with the symbiosis and are in the process of sequencing the genes to determine the structure and function of the proteins that they encode.
Dennis A. Powers, Professor and Director Marine Biology, Biochemistry, Molecular Evolution, Physiological Ecology
Dennis A. Powers, Professor and Director Marine Biology, Biochemistry, Molecular Evolution, Physiological Ecology
Stuart H. Thompson, Associate Professor Neurophysiology, Biophysics, Signal Transduction
Nerve cells process information in two different ways: electrical and chemical. Thompson's work centers on the chemical processes, particularly the role of intracellular calcium. At the cellular level, both birth and death are moderated by calcium. When a sperm contacts an egg, the egg's first response is to change its calcium level, a signal that turns on a number of cellular processes. Cell death is associated with the loss of control over internal calcium levels. Using video microscopy, Thompson can watch calcium waves and oscillations within individual nerve cells and study the internal changes that they trigger. He does so in the large neurons of the sea slug nudibranch that he collects from the intertidal region next to the research station, and in mammalian neuron cell cultures. Calcium changes also are thought to play a central role in cellular learning. He recently has determined that changes in cell shape possibly leading to new synaptic connections with neighboring nerve cells are caused by a calcium-mediated process: Certain neurotransmitters trigger a change in calcium level that turns on the production of gaseous nitric oxide, which, in turn, produces a cascade of molecular events that results in the growth of new dendrites.
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