This article contains two errors that have come to light after recent updates to the Zebrafish Information Network and the Ensemble databases.

The sequence of the translation blocker morpholino MO detailed on p. 4006 is 5′-TCCACAGG...-3′ and MO1 actually targets the intron 2/exon 3 boundary of the gata4 pre-mRNA, although this does not affect its function.

The authors apologise to readers for these mistakes.

Development132, 4005-4014.