Abstract

CCAAT/enhancer-binding protein beta (C/EBPβ), as an essential transcriptional factor, regulates the differentiation of adipocytes and the deposition of fat. Herein, we cloned the whole open reading frame (ORF) of bovine C/EBPβ gene and analyzed itsputative protein structures via DNA cloning and sequence analysis. Then, theexpression profile of this C/EBPβ gene in fifteen kinds of tissues of Qinchuan cattlewas conducted by real-time polymerase chain reaction (RT-PCR) technology. One significant outside to inside transmembrane structure located in amino acid region from 190 to 208 was observed in the putative protein sequences. Besides, one basic leucine zipper domain (bZIP) in amino acid area from 274 to 337 was found, concurring with the main characteristic of C/EBPs. Homologous comparison of the amino acid sequences from C/EBPβ cloned in this study and those from different species indicated C/EBPβ gene of Qinchuan cattle shared 97, 95 and 91% similarity with Homo sapiens, Sus scrofa and Oryctolagus cuniculus respectively, indicating a good sequence evolutional conservation of C/EBPβ. RT-PCR results revealed bovine C/EBPβ gene mRNA expression level of subcutaneous fat was the highest among all the analyzed tissues, and the relative quantity (RQ) in fat tissue increased as cattle grew. All in all, the present results could be used as basic but important genetic resource and information to inspire additional and specific studies on Qinchuan cattle.

Key words: CCAAT/enhancer-binding protein beta, molecular cloning, expression analysis.