Keywords: 
• 印记基因,DLK1,选择性剪接,组织特性表达,猪

Abstract: In this study, we isolated DNA or RNA samples from parents and F1 animals generated with reciprocal crosses between Large White and Meishan breeds to investigate the alternative splicing isoforms,imprinting status and tissue-specific expression of porcine DLK1 gene with RT-PCR, SNP and relative quantitative PCR. The sequence analysis showed that porcine DLK1 amino acid residues had N-linked glycosylation sites, high similarity to other mammalian species homology and contained epidermal growth factor (EGF) repeat motifs, and secondary structure features closely related to those present in the delta/notch/serrate family of signaling molecules. The new alternative isform, DLK1-A, as well as DLK1-B andDLK1-C2 was found expressed in the liver, heart, tongue, muscle, lung, spleen, fat, small intestine,stomach, and kidney of two-mouth-old pigs. Imprinting analysis showed that the three alternative splicingisoforms were all paternally expressed in the above tissues. The expression levels of DLK1 across tissueswere significantly different (p＜0.01). The lung and skeletal muscle had the highest DLK1 transcript abundance, followed by the tongue, spleen, and fat, which had significantly greater transcript abundance than the heart and liver did (p＜0.05). These results indicate that the DLK1 gene is conserved in mammalians. While DLK1-A or DLK1-B is expressd at some point in development, DLK1-C2 is dominantly expressed throughout the life cycle in the pig. The porcine DLK1 gene is paternally expressed in all tissues examined during development. In addition, the gene plays a necessary role in growth and development of various bodily tissues and has tissue-specific expressions.