Supplementary data - Maternal from Maternal modulation of paternal effects on offspring development.

The paternal transmission of environmentally induced phenotypes across generations has been reported to occur following a number of qualitatively different exposures and appear to be driven, at least in part, by epigenetic factors that are inherited via the sperm. However, previous studies of paternal germline transmission have not addressed the role of mothers in the propagation of paternal effects to offspring. We hypothesized that paternal exposure to nutritional restriction would impact male mate quality and subsequent maternal reproductive investment with consequences for the transmission of paternal germline effects. In the current report, using embryo transfer in mice, we demonstrate that sperm factors in adult food restricted males can influence growth rate, hypothalamic gene expression and behaviour in female offspring. However, under natural mating conditions females mated with food restricted males show increased pre- and postnatal care, and phenotypic outcomes observed during embryo transfer conditions are absent or reversed. We demonstrate that these compensatory changes in maternal investment are associated with a reduced mate preference for food restricted males and elevated gene expression within the maternal hypothalamus. Therefore, paternal experience can influence offspring development via germline inheritance, but mothers can serve as a modulating factor in determining the impact of paternal influences on offspring development.

跨代传递环境诱导表型的父系传播现象，已在多种不同性质的暴露情境中被报道，且其发生至少部分由通过精子遗传的表观遗传因子（epigenetic factors）所驱动。然而，既往针对父系生殖系传递的研究，尚未探讨母亲在父系效应传递至子代的过程中所发挥的作用。我们提出如下假说：父代暴露于营养限制环境，会影响雄性的交配质量，进而改变后续母体的生殖投资模式，最终对父系生殖系效应的传递产生影响。本研究通过小鼠胚胎移植（embryo transfer）实验证实，成年经食物限制处理的雄性个体的精子因子（sperm factors），可影响雌性子代的生长速率、下丘脑（hypothalamic）基因表达与行为表现。但在自然交配情境下，与经食物限制处理的雄性交配的雌性个体，其产前与产后抚育行为会增强，而胚胎移植实验中观察到的表型结果则不复存在或发生逆转。我们进一步证实，母体投资的这类代偿性变化，与雌性对经食物限制处理雄性的交配偏好降低，以及母体内下丘脑基因表达上调存在显著关联。综上，父代的经历可通过生殖系遗传影响子代发育，但母亲可作为调节因子，决定父系因素对子代发育的影响强度。