CROSBY, Kevin C.; BURIAN, Richard M.; WOJCIK, Edward J.; Virginia Polytechnic Institute and State University; Virginia Polytechnic Institute and State University; Virginia Polytechnic Institute and State University: Donald Poulson and the Consolidation of Drosophila Developmental Genetics

We examine Donald Poulson�s work on the genetics of early development of Drosophila in the 1930s-1950s. This work, not very influential at the time, later influenced the expansion of Drosophila developmental genetics. Poulson studied the effects on early development of lethal deletions on the X chromosome. His ideal, achieved with the notch gene, was to study the effects of single genes. He established that the effects of different genes depended, in part, on differences in the timing of their activation and proposed testing whether cytoplasm from normal embryos could rescue embryos with a lethal deficiency. Given the available techniques, this work was extremely slow and few investigators were ready to pursue it, especially when more rapid molecular techniques came to be used with more tractable microorganisms. Yet in the 1960s Eric Wieschaus, Alan Garen, and Walter Gehring, all at Yale, took up these ideas. Wieschaus joined Gehring�s group on Poulson�s advice. Poulson encouraged Garen and Gehring to work on molecular studies of development, using techniques beyond his reach. Gehring, in particular, had been trained by Ernst Hadorn, a student of Alfred K�hn, in turn a student of Theodor Boveri, in a tradition that had long considered it crucial to understand the role of development in evolution and to understand how the genes function in development. Indeed, this tradition thought such work to be a key to understanding both genetics and evolution. We suggest that it was not only the new techniques, but also the marrying of different traditions that helped the resulting lines of work to flourish.