Analysis of cpsf6 expression during zebrafish development. a) cpsf6 expression levels were monitored by RT-qPCR on cDNA from embryos of the indicated stages: 1–2 cell, 1 k-cell, 60% epiboly, 21 somites, prim-5, prim-16, long-pec and protruding-mouth. Data was normalized using gapdh mRNA levels as internal control and is shown as relative abundance comparing with 1–2 cell stage. b) Analysis of cpsf6 mRNA levels by semi quantitative RT-PCR on 1–2 cell, 1 k-cell, 20 somites and prim-5 stages. As an internal control, ef1α mRNA levels were determined on the same RNA samples. c) cpsf6 mRNA distribution in embryos at 60% epiboly and prim-5 stages analysed by whole mount in situ hybridization (scale bars: 200 μm). S: sense RNA probe (negative control), AS: antisense probe. d) Western blot analysis on extracts from 1 k-cell, 20 somites, prim-5, long-pec and protruding-mouth stages using CPSF6 antibody.