Elavl1a is the major isoform expressed during zebrafish embryogenesis. (A) A 322-bp fragment of cDNA derived from both elavl1a and elavl1b mRNA (total, T) was amplified from embryos harvested from the 1-cell (1c) stage to 120 hpf embryos, as indicated, and digested by Sca1 (S) or Bfa1 (B) restriction enzymes, which recognize polymorphisms specific to each gene. The elavl1a cDNA is cut into 120- and 200-bp fragments by Sca1, whereas elavl1b cDNA is cut into 100-bp and 220-bp fragments by Bfa1. (B) Quantification of elavl1a and elavl1b relative transcript abundance according to the data in panel A. (C) Representative embryos are shown at different embryonic stages as indicated, following in situ hybridization with the elavl1a antisense probe. No signal was detected using a control sense probe (not shown). (D) Representative embryos are shown following immunohistochemistry of Elavl1 protein at approximately the same stages. All are lateral views, other than 1- to 2-cell stages with anterior to the left. For both ISH and IHC, n > 20 embryos per sample. IHC, immunohistochemistry; ISH, in situ hybridization.