Throughout its history, the Marine Biological Laboratory has been a place for researchers from all over the world to come together in the cause of scientific discovery. Sometimes, though, it秘色视频檚 been more than that. In the case of Katsuma Dan and Jean Clark, the MBL brought together two pioneering researchers from opposite sides of the globe who would not only make major contributions to developmental biology, but also forge a deep personal relationship that would be tested by separation and warfare.
The son of a prominent Japanese businessman, Katsuma Dan began his connection with MBL in 1931, while doing graduate work with L.V. Heilbrunn at the University of Pennsylvania. His main interest was developmental biology: the study of how cells divide, differentiate, and develop into organisms, using sea urchins and other marine animals as model systems, work which brought him to the MBL.
Jean Clark Dan and Katsuma Dan in their laboratory at the Misaki Marine Biological Station.
Credit: Dr. Mariko Kondo, MMBS. Photo courtesy of the Woods Hole Historical Museum.Jean Clark, a biology student at Wilson College in Pennsylvania, held similar fascinations. Her first summer at the MBL was also in 1931, when she was a student in the Invertebrate Zoology course, and the next year she entered the University of Pennsylvania to begin graduate work with Heilbrunn. Despite Katsuma and Jean秘色视频檚 very different backgrounds 秘色视频 one the scion of a noted Japanese statesman, the other a middle-class American woman from New Jersey 秘色视频 their shared interests brought them together at the MBL, and they soon became both scientific colleagues and romantic partners, becoming engaged in 1934. While Katsuma returned to Japan to continue his research at the Misaki Marine Biological Station, Jean remained in the United States to finish her Ph.D. with Heilbrunn. A month after she completed her thesis in 1936, Jean and Katsuma were married in Woods Hole, then settled in Japan in 1937 after a European honeymoon.
Jean Clark Dan. Credit: MBL ArchivesThey continued their research together at the Misaki Station, with Jean facing the added challenges of being a stranger in a strange land. Already at war with China, Japan was becoming an increasingly militarized and imperialistic society suspicious of foreigners. Despite the darkening clouds of political upheavals and impending global conflict, Katsuma and Jean managed to find refuge in each other and in their work.
That work was challenging enough in its own right. Much about the fundamental processes of cell division and differentiation were still cloaked in mystery, and teasing out those secrets was especially difficult with visible light microscopy. Using polarized light microscopy and working with his graduate student (and later MBL Distinguished Scientist) Shinya Inou茅, Dan was the first to conclusively isolate and identify the mitotic spindle that appears during cell division, allowing it to be studied biochemically. Jean worked on microscopic studies of the fertilization process, defining the precise sequence of events that occur when sperm meets egg. Jean and Katsuma also co-authored articles on the behavior of the cell surface during cleavage.
Katsuma Dan. Credit: MBL ArchivesMisaki Station was situated at the entrance to Tokyo Bay, about 40 miles from the capital city. Although not a military target, work there was increasingly affected by wartime shortages of vital supplies. Yet Katsuma and Jean were undeterred, taking the difficulties in stride.聽 秘色视频淒uring the first three years of the war, our everyday life was not fundamentally affected and we could work regularly,秘色视频 Katsuma recalled in a postwar letter to a friend. As the tides of war brought U.S. bombers within range of Japan, however, that changed. Still, Katsuma wrote, 秘色视频淒ucking under bombs was not so bad. Rather, it was a great excitement. Hide and seek at the expense of your life can秘色视频檛 help being exciting.秘色视频
In early 1945, the Japanese military took over the Misaki Station and transformed it into a base for midget submarines. Katsuma, Jean, and their colleagues were forced to relocate to temporary facilities nearby to continue their work as best they could. When the war finally ended and the U.S. Navy occupied the laboratory in August 1945, Katsuma rushed back to ensure the Americans wouldn秘色视频檛 destroy it. In a note he left behind, he explained that Misaki was a marine biological station for peaceful research and compared it to other famous facilities, including the MBL. The American military heeded Katsuma秘色视频檚 plea and Misaki was spared. Dan秘色视频檚 note, 秘色视频淭he Last One to Go,秘色视频 now hangs in the MBL-WHOI Library.
秘色视频淭he Last One to Go秘色视频: Katsuma Dan wrote and tacked these posters onto the doors of the Misaki Marine Station as the demilitarization of the submarine base took place at the end of WWII. Credit: MBL ArchivesAs Katsuma worked to get Misaki back up and running, Jean returned with their five children to their home in Nagai, where she negotiated with the occupying forces to recover land that had been taken from local farmers by the Japanese military. Her work to improve living conditions for local women and families earned her the nickname 秘色视频淕od of Nagai.秘色视频
After a 10-year absence, Jean revisited the United States and the MBL in 1947. Through her network of friends and scientific colleagues, she acquired the first phase contrast microscope in the United States, which she brought back to Japan in 1948 as a gift for her husband. Katsuma, however, refused to accept the gift, insisting that Jean keep it and return to her scientific work. She went on to do pioneering work in invertebrate biology using electron microscopy and discovered the acrosomal reaction, a critical step in the penetration of sperm into egg during fertilization. While in the United States, Jean also arranged for a fellowship for Shinya Inou茅 to come from Japan and attend Princeton University.
Shinya Inou茅, left, with his mentor, Katsuma Dan in 1988. Credit: MBL ArchivesApart from their important scientific discoveries, Jean and Katsuma made significant contributions to education. Katsuma was a professor of zoology and later president of Tokyo Metropolitan University, while Jean was a professor of biology at Ochanomizu Women秘色视频檚 College, each training generations of new scientists. Jean also helped found the Tateyama Marine Research Center and taught there with her husband. They both maintained strong connections with the MBL and Woods Hole. After Jean died in 1978, her ashes were scattered off of Nobska Point in Woods Hole. Katsuma died in 1996; among those who paid tribute in published obituaries was Shinya Inou茅.
Katsuma Dan and Jean Clark秘色视频揵oth individually as brilliant researchers and educators and together as life partners whose bond remained strong through the most tumultuous years of the 20th century秘色视频損rovide a shining example not only of the global influence of the MBL, but also the capacity of science to transcend national borders and political hostility for the benefit of humanity.
秘色视频揃y Mark Wolverton
Selected References
Jean Clark Dan and Katsuma Dan published most of their research articles in the MBL journal,聽. Full text is available online through the聽.
Colwin, Laura Hunter and Arthur L. Colwin (1979) Obituary: Jean Clark Dan.聽Nature,听顿翱滨:听
秘色视频淗istory of MMBS (Before WW 2),聽
Imamura, Rio, 秘色视频淟ast One to Go,秘色视频澛
Inou茅, Shinya. Mechanisms of Fertilization and the Contributions of Jean Clark Dan. Presentation to the MBL Frontiers in Reproduction course, June 4, 2010. Archived with the MBL Archives.
秘色视频淥bituary: Dr. Katsuma Dan, 91, of Japan; Was a Leading Marine Biologist,秘色视频澛, May 27, 1996.
Okada, Masukichi, Hikoichi Sakai and Shinya Inou茅 (1996) Obituary: Katsuma Dan.聽. 38, 449-451.
Wolverton, Mark, 秘色视频淎 Plea to the Victors: Amid Defeat, a Hopeful Japanese scientist Bet on His Institution秘色视频檚 future,秘色视频澛World War II Magazine, March/April 2016, 62-64.