Conclusions
CELF1 and CELF2 may underlie conserved, developmentally regulated, tissue-specific processes in vertebrate embryos. Different tissues likely have unique profiles of nuclear and cytoplasmic CELF1- and CELF2-mediated functions.
Results
We found that CELF1 and CELF2 protein levels are regulated independently of transcript levels during heart development, and these proteins exhibit nuclear and cytoplasmic isoforms in the embryonic heart. We found that the subcellular distribution of CELF1 differs between heart, liver, nervous system, and eye, and identified tissue-specific isoforms of both CELF1 and CELF2 in these tissues. CELF1 and CELF2 are largely co-expressed, but are found in mutually exclusive territories in several organs, including the heart and eye. Finally, we show that the expression patterns observed in embryonic chicken were mostly recapitulated in the developing mouse, suggesting that the roles of these proteins in the tissues and cells of the developing embryo are conserved as well. Conclusions: CELF1 and CELF2 may underlie conserved, developmentally regulated, tissue-specific processes in vertebrate embryos. Different tissues likely have unique profiles of nuclear and cytoplasmic CELF1- and CELF2-mediated functions.