Three days after cRNA injection, we injected oocytes with 23 nl nuclease-free H2O or 50 ng of commercially purchased CA (C3934, Sigma, derived from bovine erythrocytes) dissolved in 23 nl nuclease-free H2O. Injection volume and bCA quantity replicate the parameters used by the Deitmer laboratory (Becker & Deitmer, 2007 (link); Schueler et al., 2011 (link)).