Rempel Lea A, Parrish John J, Miles Jeremy R
USDA, ARS, US Meat Animal Research Center, Clay Center, NE, United States.
Department of Animal Science, University of Wisconsin-Madison, Madison, WI, United States.
Front Genet. 2020 Sep 23;11:1019. doi: 10.3389/fgene.2020.01019. eCollection 2020.
Seasonal reproductive inefficiency is still observed in modern swine facilities. We previously reported global placental methylation activity was reduced from summer breedings and tended to be less from semen collected during cooler periods. The objective of the current study was to evaluate chromatin modification marks within swine placenta in relationship to breeding season, semen collection season, and semen storage. White composite gilts were artificially inseminated in August or January using single-sire semen that was collected during warm or cool periods and stored as either cryopreserved or cooled-extended. Gilts were harvested 45 days post-breeding, and placental samples from the smallest, average, and largest fetus in each litter were collected and stored at -80°C until RNA extraction. An RT Profiler assay featuring 84 known chromatin modification enzyme targets was performed using placental RNA pooled by litter. Real-time quantitative polymerase chain reaction results were analyzed using the MIXED procedure, and values were Hochberg corrected using the MULTTEST procedure in SAS. The complete model included the fixed effects of breeding season (winter or summer), semen collection season (cool or warm), semen storage (cooled-extended or cryopreserved), interactions; boar as repeated effect; and plate as random effect. If interactions were not significant, only the main effects were tested. The genes, , , and , were different ( 0.05) by interaction of breeding season, semen collection season, and semen storage. In general, the greatest ( 0.05) expression was in placentas derived from summer breedings. Expression of was also influenced by semen collection and storage. Expression of placental from winter breedings was also greater ( 0.05) from semen collected during cool periods. Placental expressions of , , , , , , , and were greater ( 0.05) from summer breedings. Increased expressions of known chromatin modification genes, from placentas derived from summer breedings, are likely responsible for differences in gene transcription between summer- or winter-derived placentas.
在现代养猪场中，季节性繁殖效率低下的情况仍然存在。我们之前报道过，夏季配种时胎盘的整体甲基化活性降低，并且在较凉爽时期采集的精液中，这种活性往往更低。本研究的目的是评估猪胎盘内染色质修饰标记与配种季节、精液采集季节和精液储存之间的关系。白色复合后备母猪于8月或1月接受人工授精，使用的单头公猪精液是在温暖或凉爽时期采集的，并分别储存为冷冻保存或低温保存。配种后45天宰杀母猪，从每窝最小、平均和最大的胎儿中采集胎盘样本，并储存在-80°C直至进行RNA提取。使用按窝混合的胎盘RNA进行了一项包含84个已知染色质修饰酶靶点的RT Profiler分析。使用MIXED程序分析实时定量聚合酶链反应结果，并使用SAS中的MULTTEST程序对值进行霍奇伯格校正。完整模型包括配种季节（冬季或夏季）、精液采集季节（凉爽或温暖）、精液储存（低温保存或冷冻保存）、交互作用的固定效应；公猪作为重复效应；以及板作为随机效应。如果交互作用不显著，则只测试主效应。基因 、 、 和 因配种季节、精液采集季节和精液储存的交互作用而存在差异（ 0.05）。一般来说，最大（ 0.05）表达出现在夏季配种的胎盘。 的表达也受精液采集和储存的影响。冬季配种的胎盘 表达在凉爽时期采集的精液中也更高（ 0.05）。 、 、 、 、 、 、 和 的胎盘表达在夏季配种时更高（ 0.05）。夏季配种胎盘来源的已知染色质修饰基因表达增加，可能是夏季或冬季来源胎盘之间基因转录差异的原因。
