Elavl1 regulates gata1 transcript levels. Shown are representative embryos following in situ hybridization for hematopoietic markers at the 5-somite (A-F) or 15-somite (G-L) stages in embryos that had been injected with 4 ng of control MO (left panels) or elavl1a Mo1 (right panels). Transcripts were analyzed for lmo2, scl, and gata1 as indicated, and embryos were flat-mounted, shown dorsal with anterior to the left. For each sample, n > 20, and the loss of gata1 transcripts (indicated by the arrows) was reproducible in independent experiments.