Abstract: The aim of this study was to construct the expression profile of adipohenin (ADIG) in different tissues of cattle and to identify its core promoter region and key transcription factors in order to elucidate the molecular mechanism of its transcriptional regulation. Heart, liver, spleen, lung, kidney, muscle and subcutaneous adipose tissues were collected from 3 ((24±2) months old) healthy Nanyang bulls, and the relative expression levels of ADIG gene in each tissue was detected by reverse transcription-polymerase chain reaction (RT-PCR). The 2 245 bp sequence of the upstream promoter region of ADIG gene was cloned, 6 pGL3-WT were constructed and cotransfected with pRL-TK into 293T cells, primary adipocytes and 3T3-L1 cells, and further bioinformatics was used to predict the key transcription factors of their core promoter region. The results showed that ADIG gene was highly expressed in lung (P<0.05), kidney (P<0.05) and subcutaneous fat (P<0.05) tissues of Nanyang cattle; the promoter sequence of ADIG gene with 2 245 bp and its 6 missing fragment sequences were cloned. pADIG-1 621/+59, pADIG-1 288/+59, pADIG-850/+59, pADIG-589/+59, pADIG-321/+59 and pADIG-79/+59 dual luciferase reporter vectors were successfully constructed, and the core region of bovine ADIG gene promoter was detected at -321/-79. Bioinformatics preliminarily predicted that the core region of bovine ADIG gene contained C/EBPα, PPARδ, CREB, STAT5 and AP-2α and other transcription factor binding sites. In summary, the bovine ADIG gene is most highly expressed in subcutaneous adipose tissue with a promoter core region located at -321/-79. Transcription factors such as C/EBPα, PPARδ, CREB, STAT5 and AP-2α have regulatory roles on the transcriptional activity of the ADIG gene. The results of this study provide a theoretical basis for exploring the improved breeding of ADIG gene at the molecular level of beef cattle.

Key words: Nanyang cattle, ADIG gene, promoter, transcriptional regulation, dual luciferase reporter gene