The symposium of which this book is a record was first suggested in the autumn of 1982. At that time, all members of the BSDB committee were persons who were primarily concerned with studies of animal development, and the initial tendency was to think along these lines.
The cytology laboratory in the University of Leicester has a long tradition in studies of the lampbrush chromosomes that are found in the growing oocytes of most animals as well as in certain stages of the life cycle of at least one simple plant, the giant unicellular alga Acetabularia mediterranea (Callan, 1982). At some stage in very early diplotene of oogenesis of an amphibian, the oocyte nucleus begins to enlarge and many regions of the nuclear chromatin begin to transcribe RNA. RNA polymerase molecules attach to hundreds of sites along the chromosomes and move progressively along the DNA strand, synthesizing long and complex molecules of RNA as they go.