Nat. Cell Biol. 17, 558–568 (2015); published online 6 April 2015; corrected after print 1 February 2016

In the version of this Article originally published, the sentence '13% of GFP–Vas granules contain nos mRNAs and 11% contain cycB' in the caption of Fig. 4h–j was incorrect; it should have read '69% of GFP–Vas granules contain nos and 51% contain cycB'. This has been corrected in all online versions of the Article.