He was one of the first foreign students to be educated at MIT and later, as president of the Japan Steel Works, he initiated and maintained close research ties with The Institute.
Katsuma Dan returned to Japan in the late 1930s and worked at the Misaki Marine Biological Station in Morioso Bay.
There was, however, an awful side to it too.” Near the end of the war the Japanese Navy took over the Misaki Marine Station and converted it into a base for miniature submarines.
[1] Dan's scientific work focused on using marine invertebrates as model organisms to study fundamental questions in cell biology and embryonic development.
He and his students focused on direct observation of cell behavior using light microscopy and discovered many of the fundamental aspects of fertilization, development, and morphogenesis (e.g., Dan and Okazaki, 1956).
To settle a long-standing debate over the existence of the mitotic spindle, he encouraged his student, Shinya Inoue, to construct polarized light microscopes and look for evidence of organized polymer networks in living cells.
A fellowship honoring Katsuma and Jean Clark Dan was established in 1979 for cultural exchange between the United States and Japan.