Sessions centered on neurobiology, cell membrane traffic, gene transcription, cell signaling and cycling, and plant defense and pathogenesis. For example, the scatter factors described by Paolo Comoglio, of the Institute for Cancer Research in Turin, are needed for development of many types of tissue. Additionally, Comoglio's lab has demonstrated that certain point mutations in these specialized factors can transform healthy growth into malignancy, showing that they play a role in pathogenesis, as well. In a presentation that helped explain the workings of whole organisms rather than tissues, Charles Weitz, assistant professor of neurobiology at HMS, described the molecular mechanisms of endogenous, self-sustaining clocks that have been found in everything from bacteria and fungi to plants, invertebrates, and humans. Only a year ago, researchers at Northwestern University identified the first mammalian circadian gene.
Further experiments indicate that teamwork is the key.
Now that it is clear that these two proteins turn on per , Weitz said, the next challenge is to figure out what turns the gene off during normal circadian rhythms. Speakers at a session on plant defense and pathogenesis took an even broader view, blurring traditional boundaries by demonstrating that the animal and plant kingdoms are more alike, in at least some regards, than previously thought. Frederick Ausubel, professor of genetics at HMS and MGH, described how novel pathogens made in his lab can cause disease in certain model plants, flies, nematodes, and mice. Strains that are especially virulent in plants, Ausubel said, are often even more pathogenic in animals. Felice Cervone and Giulia De Lorenzo, plant biologists from the University of Rome, made the case that plants, like animals, readily identify nonself molecules that may pose a threat to them.