Tracking heterochromatin

The Second International Workshop on Drosophila Heterochromatin, held in Honolulu from January 4-7, 1995, brought together about 70 scientists from the US, Canada, Germany, Italy, Russia, and the Netherlands. After the first of these international meetings, five years ago, Mary Lou Pardue and Wolfgang Hennig, in these columns, commented on its proceedings, and on heterochromatin in general. Although the questions that they raised cannot yet be answered exhaustively, important and sometimes surprising new observations have been made, some previously tentative answers have been firmed up, and some theoretical views underwent significant shifts. We wish to reflect here a few of the data presented at the second workshop, and express some thoughts suggested to us by these recent findings.