Wang Kejun, Li Wenting, Bai Ying, Yang Wanjie, Ling Yao, Fang Meiying
Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, People's Republic of China.
Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, People's Republic of China; College of Agriculture, Hebei University of Engineering, Handan 056021, People's Republic of China.
Int J Biol Sci. 2017 Jan 17;13(2):189-197. doi: 10.7150/ijbs.17386. eCollection 2017.
Castration of male pigs is a common practice used to reduce boar taint in commercial pork production, but it also significantly results in fat accumulation in carcass. Our previous study revealed a miRNA gene, ssc-miR-7134-3p that was implicated in adipogenesis. However, the relationship between ssc-miR-7134-3p and fat deposition due to castration is unknown. In the present study, we observed that ssc-miR-7134-3p targets the coding sequence (CDS) region of MARK4 based on bioinformatics analysis and dual-luciferase assays. Experiments using silent mutations and sub-cloning showed that ssc-miR-7134-3p binds independently to two adjacent sites in the MARK4 CDS. Subsequently, ssc-miR-7134-3p inhibits MARK4 protein expression in pig fibroblast cells, being consistent with the targeting demonstrated in vitro. We found higher MARK4 protein levels in the back fat of castrated pigs than in intact pigs, providing further evidence that MARK4 is involved in regulation of fat deposition. In addition, one SNP (g.2581A>G) in MARK4 was significantly associated with the back fat trait in Chinese and European pig populations. Taken together, we would conclude that ssc-miR-7134-3p targets the MARK4 gene for fat accumulation in the castrated male pigs.
对公猪进行阉割是商业猪肉生产中减少公猪异味的常用做法，但这也会显著导致猪胴体脂肪堆积。我们之前的研究发现了一个与脂肪生成有关的 miRNA 基因 ssc-miR-7134-3p。然而，ssc-miR-7134-3p 与阉割导致的脂肪沉积之间的关系尚不清楚。在本研究中，基于生物信息学分析和双荧光素酶检测，我们观察到 ssc-miR-7134-3p 靶向 MARK4 的编码序列（CDS）区域。使用沉默突变和亚克隆的实验表明，ssc-miR-7134-3p 独立结合到 MARK4 CDS 中的两个相邻位点。随后，ssc-miR-7134-3p 在猪成纤维细胞中抑制 MARK4 蛋白表达，这与体外实验证明的靶向作用一致。我们发现阉割猪的背膘中 MARK4 蛋白水平高于未阉割猪，这进一步证明 MARK4 参与脂肪沉积的调节。此外，MARK4 中的一个单核苷酸多态性（g.2581A>G）在中国和欧洲猪种群体中与背膘性状显著相关。综上所述，我们得出结论：ssc-miR-7134-3p 通过靶向 MARK4 基因影响阉割公猪的脂肪堆积。
