Nature Cell Biology is delighted to welcome you to this special issue, 'Focus on Development', which we hope will be of interest not only to researchers within the field, but also to our readers in other disciplines.

Developmental biologists often define themselves as a subset of researchers according to the organism they study; for example they may be Drosophila geneticists, Xenopus researchers, zebrafish cell biologists or mouse experts. How a specific organism or group of cells develops anteroposterior polarity, how groups of cells differentiate into specific organs, or how regions of a developing embryo are patterned, are all fundamental questions that are tackled by developmental biologists. The answer to all these questions resides within and involves understanding core cell biological concepts and their implications.

We have brought together an exciting selection of commissioned pieces and primary research to reflect the link between cell biology and developmental biology. In recognition of the importance of this field, we are pleased to announce that this issue will be free online during July 2001 at http://cellbio.nature.com. Furthermore, we are launching a new “Focus on Development” site on our homepage that will contain all the previous developmental biology publications from Nature Cell Biology. This new “Focus on Development” site will complement our existing Focus sites on “Membrane Traffic”, “Cytoskeleton” and “Cell Divison”. It will be continuously updated to contain all the work published in this field by Nature Cell Biology. Please see http://www.nature.com/ncb/webfocus/development/ for further details.

History of development

In this special issue, we hope you will enjoy the primary research papers: they include a brief communication from Aaronson and colleagues (p. 683), which reveals the mechanism of action of Dickkopf within the Wingless signalling pathway, and two articles from Raff and colleagues (p. 643) and from Cullen and Ohkura (p. 637), which define how Mini-spindles interacts with D-TACC to regulate microtubule behaviour.

To complement these primary research publications, we have a selection of commissioned pieces. These include a commentary by Peter A. Lawrence, who examines the history of morphogens in developmental biology and analyses the latest work in this field; another commentary by Marcel van den Heuvel, who focuses on signalling proteins that drive cells into proliferation and/or differentiation; an historical perspective by Brigid Hogan and Molly Weaver, who looks at the evolution of techniques in experimental embryology. There are also book reviews and a meeting report from the recent British Society of Developmental Biology symposium.

We would also like to take this opportunity to pay tribute to Rosa Beddington who died on 18 May 2001 after a long battle against cancer. She will be remembered for her pioneering work in mouse embryonic development. In particular, her identification of the organizer region in the mouse embryo, and the role of the antero-visceral mesoderm in the induction of embryonic tissues, permanently altered the field of mammalian development.

Nature Cell Biology strives to be the primary cell biology journal in which to publish the most exciting and influential work in developmental biology. We look forward to hearing your feedback on our focus issue and we hope you enjoy the free online access in July 2001.