Effect of TCDD exposure in adult female and male mice on the expression of miRNA in the ovaries and testes and associated reproductive functions. Effect of TCDD exposure in adult female and male mice on the expression of miRNA in the ovaries and testes and associated reproductive functions

The current study demonstrates for the first time that exposure of adult male and female mice to TCDD results in significant alterations in a large number of miRNAs in the ovaries and the testes. These findings suggest that environmental contaminants such as TCDD may alter reproductive functions through alterations in the expression of miRNAs. Future studies will focus on whether such miRNA changes also occur in the germ cells which would explain how TCDD exerts transgenerational effects on the reproductive system by regulating epigenetic pathways involving miRNA Overall design: Mice were dosed at 10µg/kg body weight. Male and female mice were either treated with TCDD or vehicle, the latter consisting of an equal amount of DMSO in corn oil, On day 3, ovaries and testes were harvested and single cell suspensions were prepared. miRNA arrays were performed using total RNAs including microRNA and using Affymetrix microarray platform

本研究首次证实，成年雄性与雌性小鼠暴露于2,3,7,8-四氯二苯并对二噁英（TCDD）后，其卵巢与睾丸内大量微小RNA（miRNA）的表达出现显著改变。上述结果提示，诸如TCDD这类环境污染物可通过调控miRNA的表达水平，进而改变生物体的生殖系统功能。后续研究将聚焦于此类miRNA表达变化是否同样存在于生殖细胞中，以此阐明TCDD如何通过调控涉及miRNA的表观遗传通路，对生殖系统产生跨代影响。整体实验设计如下：小鼠以10μg/kg体重的剂量进行染毒处理，分为TCDD处理组与溶剂对照组，其中溶剂对照组为在玉米油中添加等量二甲基亚砜（DMSO）。于染毒后第3天采集卵巢与睾丸组织并制备单细胞悬液；采用包含miRNA在内的总RNA，依托Affymetrix微阵列平台完成miRNA芯片检测。