Plant studies are plant studies and animal studies are animal studies and never the twain shall meet. Though few biologists would endorse that description as a desirable state of affairs, many would agree that it is a fairly accurate one. To help bridge the gap between the two kingdoms, or, more accurately, between the two groups of researchers, a conference on pattern formation in plants and animals was organized by the John Innes Institute, in collaboration with the British Society for Developmental Biology. The 'Molecular and Cellular Basis of Pattern Formation' took place in September, the 3rd to the 6th, at the University of East Anglia (Norwich, UK) and was attended by 230 participants, predominantly from the UK and the US, but with significant participation from continental Europe and some attendees from other countries.
Saturation Mutagenesis and Analysis of Pattern
The conference opened with the 14th Bateson Memorial Lecture from C. Nusslein-Volhard (Tubingen), who described the work from her laboratory on the strict maternal effect mutants of Drosophila that identify genes essential for organizing the early embryonic pattern of the fruit fly. This analysis has identified 30 genes to date, whose actions define four functional groups of maternal effect genes required for pattern formation in four fairly distinct spatial domains. Three of these gene groups are required for organizing the antero-posterior axis (the anterior, posterior, and terminal groups) and the fourth, the dorso-ventral (d-v) axis. Each group is involved with the production of a localized signal but there are significant differences in molecular mechanisms associated with each of these signals. Strikingly, both the d-v system and the terminal system involve membrane transduction systems that mediate localized reactions to external signals originating in the perivitelline fluid.
There is, as yet, no plant model system that has been analyzed with the same genetic scrutiny as Drosophila, but Arubidopsis, possessing a small genome and a short generation time, may have the same potential. G. Jurgens (Munich), a former colleague of Nusslein-Volhard's, presented the work of his laboratory on the search for mutants affecting pattern in the early embryo of Arubidopsis. Of MOO0 separate lines, derived from