The actin-bundling protein fascin 1 is expressed at specific times and places during development, and is often expressed in tumours. Fascin 1 has a clear role in cell migration in vitro but what is its role in vivo? To answer this question, Laura Machesky and co-workers have been studying the role of fascin 1 in the mouse melanocyte lineage and in human melanoma cells (p. 2203). They report that fascin 1 knockout mice have hypopigmentation defects that arise from reduced melanoblast migration and proliferation during embryogenesis. By studying live embryo skin explants, they show that fascin 1-null melanoblasts migrate and differentiate in the skin but with a lower efficiency than wild-type melanoblasts. They also show that fascin 1 depletion slows melanoblast proliferation in vivo and human melanoma cell growth in vitro. The researchers suggest, therefore, that transient expression of fascin 1 in mouse melanoblasts during embryogenesis promotes their migration and proliferation, and that fascin 1 expression may aid the proliferation and invasion of some tumour cells.

© 2013. Published by The Company of Biologists Ltd
2013