Abstract：Through PCR amplification, 5’-flanking region and partial open reading frame of the β-actin gene of Nile tilapia（Oreochromis niloticus）was obtained. The sequence includes 1643 bp regulatory sequence and 90 bp of partial ORF which encodes a 30 amino acids peptide. The 1643 bp regulatory sequence which contains 108bp 5’ proximal promoter，the first untranslated exon and the first intron of β-actin gene. The proximal promoter region contains elements that were critical for transcription activity, including the CCAAT Box，TATA Box，CArG Box which respectively located at -92，-29，-62bp upstream of transcription initiation site. The regulatory sequence was inserted into the promoterless pDsRed2-1 vector. The linearized recombinant plasmid was microinjected into the fertilized eggs of white cloud mountain minnow. DsRed2 expressed in transgenic fish and red fluorescence could be observed by micro fluoroscope and anatomical lens. The results showed that the β-actin gene promoter possess effective transcription activity. The present study lays a foundation for the further autotransgene nile tilapia research.
