Comment

Breakthroughs in microscopy technology provide new in-sights into cell biology. Early microscopes allowed Robert Hooke to see cells. Improved staining techniques enabled Camillo Golgi to see the apparatus that bears his name, and Robert Feulgen to visualize DNA in chromosomes. Similarly, EM allowed Keith Porter to visualize the en-domembrane system. More recently, transgenic technol-ogy using fluorescent reporter proteins has enabled us to visualize cryptic or ephemeral processes and structures in living cells. The latest revelation with this technology is in chloroplast biology. On page 945 of this issue, Kiessling et al. show that fusion of green fluorescent protein (GFP) 1 with the FtsZ (filament temperature sensitive Z) protein targeted to chloroplasts of the mos