Gabriella Ficz, Rainer Heintzmann and Donna J. Arndt-Jovin Development132,3963-3976.

The e-press version of this article that was published on the 3rd August contains an error in Equation 1 and the preceding sentence on p. 3965.

Both the published print and online versions of this article are correct.

We apologise to the authors and readers for this mistake.