Helmholtz Centre for Ocean Research Kiel, Evolutionary Ecology of Marine Fishes, Germany.
Am Nat. 2012 Dec;180(6):802-14. doi: 10.1086/668081. Epub 2012 Oct 31.
In vertebrates, maternal transfer of immunity via the eggs or placenta provides offspring with crucial information on prevailing pathogens and parasites. Males contribute little to such transgenerational immune priming, either because they do not share the environment and parasite pressure of the offspring or because sperm are too small for transfer of immunity. In the teleost group of Syngnathids (pipefish, seahorses, and sea dragons), males brood female eggs in a placenta-like structure. Such sex-role-reversed species provide a unique opportunity to test for adaptive plasticity in immune transfer. Here, males and females should both influence offspring immunity. We experimentally tested paternal effects on offspring immunity by examining immune cell proliferation and immune gene expression. Maternal and paternal bacterial exposure induced offspring immune defense 5 weeks after hatching, and this effect persisted in 4-month-old offspring. For several offspring immune traits, double parental exposure (maternal and paternal) enhanced the response, whereas for another group of immune traits, the transgenerational induction already took place if only one parent was exposed. Our study shows that sex role reversal in connection with male pregnancy opens the door for biparental influences on offspring immunity and may represent an additional advantage for the evolution of male pregnancy.
在脊椎动物中，母体通过卵子或胎盘将免疫力传递给后代，为其提供有关流行病原体和寄生虫的关键信息。雄性在这种跨代免疫启动中贡献甚少，要么是因为它们不与后代共享环境和寄生虫压力，要么是因为精子太小而无法传递免疫力。在硬骨鱼纲的海龙目（海龙、海马和叶海龙）中，雄性在胎盘状结构中孵化雌性卵子。这种性别反转的物种为测试免疫传递中的适应性可塑性提供了独特的机会。在这里，雄性和雌性都应该影响后代的免疫力。我们通过检查免疫细胞增殖和免疫基因表达来实验性地测试父本对后代免疫力的影响。母本和父本细菌暴露在孵化后 5 周诱导了后代的免疫防御，这种效应在 4 个月大的后代中仍然存在。对于一些后代的免疫特征，双亲暴露（母本和父本）增强了反应，而对于另一组免疫特征，如果只有一个亲本暴露，就已经发生了跨代诱导。我们的研究表明，与雄性怀孕相关的性别角色反转为双亲对后代免疫力的影响打开了大门，并且可能是雄性怀孕进化的另一个优势。
