Key Lab of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education and Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, People's Republic of China.
PLoS One. 2012;7(8):e43325. doi: 10.1371/journal.pone.0043325. Epub 2012 Aug 24.
Imprinted genes play important roles in placental and embryonic development. Neuronatin (NNAT), first identified as an imprinted gene in human and mouse brains, played important roles in neuronal differentiation in the brain and in glucose-mediated insulin secretion in pancreatic β cells. In the pig, NNAT was reported to be imprinted in eleven tissues. Our previous microarray hybridization study showed that NNAT was differentially expressed in Yorkshire and Meishan pig placentas, but the imprinting status and function of NNAT in the placenta have not been investigated. We demonstrated for the first time that NNAT was monoallelically expressed in the placenta. Immunochemistry analysis showed that NNAT was located in the uterine luminal and glandular epithelium in placentas. We also confirmed the differential expression of NNAT in Meishan and Yorkshire pig placentas by qPCR. Using IPA software and the published literature, we created a model network of the possible relationships between NNAT and glucose transporter genes. A dual luciferase reporter assay demonstrated that the crucial promoter region of NNAT contained a CANNTG sequence in the +210 to +215 positions, which corresponded to the E-box. Our findings demonstrated important roles of NNAT in placenta function.
印迹基因在胎盘和胚胎发育中发挥重要作用。神经氨酸酶（NNAT）最初在人和小鼠大脑中被鉴定为一个印迹基因，在大脑中的神经元分化和胰腺β细胞中葡萄糖介导的胰岛素分泌中发挥重要作用。在猪中，NNAT 被报道在 11 种组织中被印迹。我们之前的微阵列杂交研究表明，NNAT 在约克夏和梅山猪胎盘中差异表达，但 NNAT 在胎盘中的印迹状态和功能尚未得到研究。我们首次证明 NNAT 在胎盘中单等位基因表达。免疫化学分析表明，NNAT 位于胎盘的子宫腔和腺上皮中。我们还通过 qPCR 证实了 NNAT 在梅山和约克夏猪胎盘中的差异表达。使用 IPA 软件和已发表的文献，我们创建了一个 NNAT 与葡萄糖转运基因之间可能关系的模型网络。双荧光素酶报告基因检测表明，NNAT 的关键启动子区域在+210 到+215 位置含有一个 CANNTG 序列，与 E 盒相对应。我们的研究结果表明 NNAT 在胎盘功能中发挥重要作用。
