Thünen Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg, Germany.
Thünen Institute of Fisheries Ecology, Wulfsdorfer Weg 204, 22926 Ahrensburg, Germany.
Comp Biochem Physiol Part D Genomics Proteomics. 2021 Sep;39:100838. doi: 10.1016/j.cbd.2021.100838. Epub 2021 Apr 20.
Environmental enrichment is used to increase structural complexity of captive rearing systems and has been shown to provoke a wide range of effects in the kept animals. Here we studied the effects of enrichment on DNA methylation patterns at the whole-genome level in the brain of rainbow trout reared in an aquaculture setting. We investigated the epigenetic effects between different types of enrichment (natural substrate vs. artificial substrate vs. barren) in three developmental stages (egg vs. alevin vs. fry) and as enrichment was discontinued at the fingerling stage by means of the Methylation-Sensitive Amplified Polymorphism (MSAP) technique. While enrichment did not affect growth in body size, we found enrichment to affected global DNA methylation in the brain at the egg and alevin stage, i.e., the period during development where the animals are in close physical contact with the substrate. At these stages, trout reared on the two substrates differed more from the control than the substrates differed from each other. Only minor differences between rearing environments were detected following emergence at the fry stage. When enrichment was discontinued during the rearing of fingerlings, no differences in DNA methylation patterns were observed between the rearing environments. Our results provide further evidence on the effects of enrichment in the captive rearing of fish and show that enrichment can even modulate epigenetic patterns. The effect on the epigenome may be causal for the previously reported effects of enrichment on gene expression, behaviour and brain development.
环境丰容被用于增加圈养繁殖系统的结构复杂性，并且已被证明会在被饲养的动物中引发广泛的影响。在这里，我们研究了丰容对养殖虹鳟鱼大脑全基因组水平 DNA 甲基化模式的影响。我们在三个发育阶段（卵、仔鱼和鱼苗）中研究了不同类型的丰容（天然基质与人工基质与贫瘠）之间的表观遗传效应，以及在鱼苗阶段通过甲基化敏感扩增多态性（MSAP）技术停止丰容时的效应。虽然丰容不会影响体型的生长，但我们发现丰容会影响卵和仔鱼阶段大脑的整体 DNA 甲基化，即动物与基质密切接触的发育阶段。在这些阶段，与对照组相比，在两种基质上饲养的鳟鱼与基质之间的差异更大。在鱼苗阶段出现后，仅在养殖环境之间检测到较小的差异。当在鱼苗的饲养过程中停止丰容时，在不同的养殖环境之间未观察到 DNA 甲基化模式的差异。我们的研究结果进一步证明了丰容对鱼类圈养的影响，并表明丰容甚至可以调节表观遗传模式。对表观基因组的影响可能是丰容对先前报道的基因表达、行为和大脑发育影响的原因。
