Warming up at the poles.

Introduction This series of meetings (Palazzo, 2002; Stearns & Winey, 1997) began as a joint ASCB/EMBO venture in 1997 with a meeting that was a landmark event, not only because a minor field had grown to fill an entire meeting, but also because key presentations defined the course of the field for years to come. The first biochemical mass spectrometric analysis of the budding yeast spindle pole body (SPB) by John Kilmartin and Matthias Mann marked the dawn of a new era in centrosome and SPB studies (Wigge et al, 1998). Similarly, Jeff Salisbury’s clear demonstration of centrosome amplification in tumour samples, coupled with the work of Bill Brinkley, Stephen Doxsey and others, was part of a resurrection of Theodor Boveri’s turn-of-the-century hypothesis that centrosome amplification could lead to genetic instability and cancer (Brinkley, 2001). However, all was not harmonious, as elegant work describing spindle assembly in centrosome-free Xenopus extracts (Heald et al, 1996), coupled with studies showing Drosophila development in the absence of functional centrosomes, sparked a key debate at the 1997 meeting that persists to this day. The root of this controversy lies in the ability of spindles to form and apparently function without centrosomes. Mass spectrometry continued to set the pace at the second meeting in 2002, as Erich Nigg and Mann’s groups defined a set of centrosome components that have become the staple diet for the community ever since (Andersen et al, 2003). However, more contention arose at the second meeting as a result of the stunning laser ablation studies by Alexy Khodjakov that challenged another of Boveri’s hypotheses—that centrioles can only be made in the presence of an existing centriole template. After a three-year wait, eager ‘pole-heads’ returned to Heidelberg in September 2005, to be swept into another deluge of information and insights provided by a third fast-paced and exciting meeting.