Abstract: The aim of this study was to analyze the activity region and transcription factors in the promoter of goose MyoG gene, and to elucidate the transcriptional regulation mechanism. Firstly, the 1 245 bp 5' flanking region of MyoG was amplified by PCR, followed by sequencing and bioinformatics analysis. Secondly, dual luciferase reporter vectors with 4 different deletion fragments of the promoter were constructed, and then transfected into C2C12 cell lines. Furthermore, the key transcription factor in the core promoter region was predicted using online software, site-directed mutagenesis of the transcription factor binding sites HNF4 (—521-—503 bp), USF (—379-—370 bp) and E2 (—296-—281 bp) were carried out, then 3 mutation reporter vectors were constructed, and the key transcription factors of MyoG gene was preliminary identified in C2C12 cell line. Finally, the expression profile of MyoG and key transcription factor in breast muscle, leg muscle, heart, liver, spleen, lung, kidney and hypothalamus of 70-day-old goose were determined through qPCR. The results showed that the amplified 5' flanking region of MyoG gene contained promoter elements. The key cis-regulatory elements was located at —624-—154 bp region using the dual luciferase reporter vector. Combined with site-directed mutation demonstrated that USF was the key transcription regulatory factor of goose MyoG gene. Tissue expression profile studies further revealed that MyoG and USF expressed in 8 tissues, and they were higher co-expressed in goose breast muscle, leg muscle and heart (P<0.01). The 5' flanking region of goose MyoG had promoter transcriptional activity, the core promoter region was detected at -624-+37 bp, and USF was the key transcription regulatory factor. The experimental results can provide a theoretical basis for exploring molecular regulation mechanism of MyoG gene in goose muscle development.

Key words: goose, MyoG gene, promoter activity, site-directed mutation, transcriptional regulation