Modulation of embryonic development due to mating with immunised males.

The modification of pre- and postnatal development conferred by immunogenic stimulation of mothers provides a population-level adaptation mechanism for non-genetic transfer of maternal experiences to progeny. However little is known about the transmission of paternal immune experiences to offspring. Here, we show that immune priming of males 3-9 days before mating affects the growth and humoral environment of developing embryos of outbred (ICR) and inbred (C57BL and BALB/c) mice. Antigenic stimulation of fathers caused a significant increase in embryonic bodyweight as measured on Day 16 of pregnancy and altered other gestation parameters, such as feto-placental ratio. Pregnant females mated with immunised males were also characterised by changes in humoral conditions as shown by measurements of blood and amniotic progesterone, testosterone and granulocyte-macrophage colony-stimulating factor (GM-CSF) cytokine concentrations. These results emphasise the role of paternal effects of immune priming on the in utero environment and fetal growth.