1999 Volume 65 Issue 4 Pages 600-605
First-strand cDNA was synthesized from total RNA of larvae at hatching of the carp Cyprinus carpio by reverse-transcription reaction. Subsequently, a cDNA clone encoding E12 transcription factor was isolated by PCR with several combinations of primers. The DNA fragment finally obtained comprised 849 and 593 by of the coding and 3' non-coding regions, respectively, encoding a partial length of carp E12. The deduced amino acid sequence of carp E12 showed high identity with corresponding regions from other vertebrates (51-81%), particularly in the basic helix-loop-helix domain (approximately 90%). In northern blot analysis, carp E12 transcripts were detected at various developmental stages, suggesting that carp E12 is implicated in cell proliferation and differentiation during ontogeny as those of other vertebrates. The mRNA signals were still recognized in the muscle from 7-month-old juveniles, while markedly reduced compared to those in embryos. Therefore, it seems that carp E12 plays an important role in the formation of new myofibers even after hatching. Carp E12 transcripts were also expressed in various tissues, though with small quantities in the muscle, of adult fish aged 2 years, suggesting that this transcription factor is involved in many tissue-specific gene transcriptions.
