NNAT and DIRAS3 genes are paternally expressed in pigs Huan-Chen Cheng, Feng-Wei Zhang, Chang-Yan Deng, Cao-De Jiang, Yuan-Zhu Xiong, Feng-E Li and Ming-Gang Lei Genet. Sel. Evol., 39 5 (2007) 599-607 Published online: 27 September 2007 DOI: 10.1051/gse:2007024