U.S. Department of Agriculture, ARS, U.S. Meat Animal Research Center, Clay Center, Nebraska.
Department of Animal Science, University of Wisconsin, Madison, Wisconsin.
Mol Reprod Dev. 2019 Apr;86(4):465-475. doi: 10.1002/mrd.23125. Epub 2019 Feb 14.
Epigenetics includes the study of external factors that can influence the expression of genes by altering the accessibility of DNA through methylation. To investigate the epigenetic influence of season, sperm head shape, and semen storage on placental and fetal tissues, pregnancies were generated in the summer or winter using boar semen from either least or most sperm head shape change, collected during cool or warm seasons, and stored as cooled-extended or cryopreserved. The lowest (p < 0.05) ratios of 5-methylcytosine to 5-hydroxymethylcytosine activity (5mC:5hmC) in fetal liver were from summer breedings and in placental tissues from winter breedings. The relative expression of placental CDH1 tended ( p < 0.10) to be greater in placenta generated from cryopreserved semen or semen collected during cool periods. The relative expression of placental GNAS was affected ( p < 0.05) by the interaction of breeding and semen collection seasons. Cryopreserved semen increased ( p < 0.05) the placental relative expression of GNAS. Placental MEST and RHOBTB3 tended ( p < 0.10) to have a greater relative expression from pregnancies generated using semen collected during cool periods used during winter breedings. Within fetal liver, the relative expression of GNAS and HGF was greater ( p < 0.05) from winter breedings. Interaction of winter breedings and least sperm head shape change tended ( p < 0.10) to have the greatest fetal liver expression of CDH1. Seasonality of semen collection, breeding, and the effect on sperm head shape change had an influence on the expression of genes with known differentially methylated regions or response to methylation activity from embryonic and extraembryonic tissues.
表观遗传学包括研究外部因素对 DNA 可及性的改变，从而影响基因表达的甲基化。为了研究季节、精子头部形状和精液储存对胎盘和胎儿组织的表观遗传影响，使用来自夏季或冬季的公猪精液进行繁殖，这些精液来自精子头部形状变化最小或最大的公猪，在凉爽或温暖的季节采集，并以冷却延长或冷冻保存的方式储存。胎儿肝脏中 5-甲基胞嘧啶与 5-羟甲基胞嘧啶活性（5mC：5hmC）的最低比值（p<0.05）来自夏季繁殖，而胎盘组织则来自冬季繁殖。胎盘 CDH1 的相对表达在冷冻精液或凉爽时期采集的精液产生的胎盘组织中趋于更大（p<0.10）。胎盘 GNAS 的相对表达受到繁殖和精液采集季节相互作用的影响（p<0.05）。冷冻精液增加了胎盘 GNAS 的相对表达（p<0.05）。胎盘 MEST 和 RHOBTB3 的相对表达在冬季繁殖期间使用凉爽时期采集的精液产生的妊娠中趋于更大（p<0.10）。在胎儿肝脏中，冬季繁殖时 GNAS 和 HGF 的相对表达更高（p<0.05）。冬季繁殖和精子头部形状变化最小的相互作用倾向于具有最大的胎儿肝脏 CDH1 表达（p<0.10）。精液采集、繁殖和精子头部形状变化的季节性对胚胎和胚胎外组织中已知差异甲基化区域或对甲基化活性有反应的基因的表达有影响。
