Wang Dan, Ning Chao, Xiang Hai, Zheng Xianrui, Kong Minghua, Yin Tao, Liu Jianfeng, Zhao Xingbo
1National Engineering Laboratory for Animal Breeding; Ministry of Agricultural Key Laboratory of Animal Genetics, Breeding and Reproduction; College of Animal Science and Technology, China Agricultural University, Beijing, 100193 China.
2School of Life Science and Engineering, Foshan University, Foshan, 528225 China.
J Anim Sci Biotechnol. 2018 Nov 26;9:86. doi: 10.1186/s40104-018-0299-0. eCollection 2018.
Mutations in mitochondrial tRNA genes have been widely reported association with human reproductions. It is also important to explore the effect on the number of piglets born alive (NBA). Here, 1017 sows were used to investigate the association between polymorphisms in mitochondrial tRNA genes and NBA.
In total, 16 mutations were found in mitochondrial tRNA genes, of which 13 mutations were significantly associated with NBA ( < 0.05). The reproductions of mutant carriers were significantly greater than that of wild carriers by 0.989 piglets born alive/sow farrowing. To test whether the mutations altered the structure of mitochondrial tRNAs, the secondary and tertiary structures were predicted. In result, C2255T changed the secondary structure of tRNA-Val by elongating the T stem and shrinking the T loop, and C2255T and G2259A in the tRNA-Val gene, C6217T and T6219C in the tRNA-Ala gene, and T15283C in the tRNA-Glu gene altered the tertiary structure of their tRNAs, respectively by changing the folding form of the T arm, and C16487T in the tRNA-Thr gene changed the tertiary structure of mitochondrial tRNA-Thr by influencing the folding form of the acceptor arm.
Results highlight the effect of mitochondrial tRNA genes on the number of piglets born alive, and suggest that polymorphic sites of the tRNA genes be genetic markers for selection of pig reproduction.
线粒体tRNA基因的突变与人类生殖的关联已有广泛报道。探究其对产活仔数（NBA）的影响也很重要。在此，使用1017头母猪来研究线粒体tRNA基因多态性与NBA之间的关联。
在线粒体tRNA基因中总共发现了16个突变，其中13个突变与NBA显著相关（<0.05）。突变携带者的繁殖力比野生携带者显著高出0.989头产活仔数/产仔母猪。为了测试这些突变是否改变了线粒体tRNA的结构，对其二级和三级结构进行了预测。结果显示，C2255T通过延长T茎和缩短T环改变了tRNA-Val的二级结构，tRNA-Val基因中的C2255T和G2259A、tRNA-Ala基因中的C6217T和T6219C以及tRNA-Glu基因中的T15283C分别通过改变T臂的折叠形式改变了其tRNA的三级结构，tRNA-Thr基因中的C16487T通过影响受体臂的折叠形式改变了线粒体tRNA-Thr的三级结构。
结果突出了线粒体tRNA基因对产活仔数的影响，并表明tRNA基因的多态性位点可作为猪繁殖选择的遗传标记。
