Gallery Tweet Banner above. Left: Arl13b-Fucci2a labelled NIH3T3 cells (Matt Ford). Right H2B-Cerulean and EYFP labelled melanoblasts migrate in embryonic skin (Richard Mort). Live imaging of H2BCerulean-Fucci2a labelled NIH 3T3 nuclei. (Stephanie Wright) Live imaging of Qucci labelled NIH 3t3 cells (Tiernan Briggs) Live image of developing somites of an E11.5 mouse embryo labelled with Arl13bCerulean-Fucci2a. (Mill/Ford). Melanocytes and macrophages in mouse tail skin (Emma Wilkinson) Live image of Arl13bCerulean-Fucci2a labelled NIH 3T3 cells. (Mill/Ford). Live image of developing prosencephalon of an E8.5 mouse embryo labelled with Arl13bCerulean-Fucci2a. (Mill/Ford). Live image of EYFP/H2BCerulean labelled melanoblasts migrating on the dorsal lateral pathway. (Richard Mort) Live image of cKit-sfGFP/mCherry ‘timer tag’ labelled NIH 3T3 cells. (Olivia Harrison) Depth coded stack of mouse melanoblasts as they begin to colonise a developing hair follicle at E14.5 (Richard Mort)