Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Ås, Norway.
Epigenetics. 2024 Dec;19(1):2305079. doi: 10.1080/15592294.2024.2305079. Epub 2024 Jan 28.
An earlier study of ours investigating the effect of dietary lipid levels on the choline requirement of Atlantic salmon showed increasing severity of intestinal steatosis with increasing lipid levels. As choline is involved in epigenetic regulation by being the key methyl donor, pyloric caeca samples from the study were analysed for epigenetic effects of dietary lipid and choline levels. The diets varied in lipid levels between 16% and 28%, and choline levels between 1.9 and 2.3 g/kg. The diets were fed for 8 weeks to Atlantic salmon of 25 g of initial weight. Using reduced representation bisulfite sequencing (RRBS), this study revealed that increasing dietary lipid levels induced methylation differences in genes involved in membrane transport and signalling pathways, and in microRNAs important for the regulation of lipid homoeostasis. Increasing choline levels also affected genes involved in fatty acid biosynthesis and transport, lipolysis, and lipogenesis, as well as important immune genes. Our observations confirmed that choline is involved in epigenetic regulation in Atlantic salmon, as has been reported for higher vertebrates. This study showed the need for the inclusion of biomarkers of epigenetic processes in studies that must be conducted to define optimal choline levels in diets for Atlantic salmon.
我们之前的一项研究调查了膳食脂质水平对大西洋鲑胆碱需求的影响，结果表明随着脂质水平的升高，肠道脂肪变性的严重程度也随之增加。由于胆碱作为关键的甲基供体参与表观遗传调控，因此从研究中提取幽门盲囊样本，分析了膳食脂质和胆碱水平对其的表观遗传影响。这些饮食的脂质水平在 16%到 28%之间变化，胆碱水平在 1.9 到 2.3 g/kg 之间变化。这些饮食喂养了初始体重为 25 克的大西洋鲑 8 周。通过简化代表性亚硫酸氢盐测序（RRBS），本研究揭示了增加膳食脂质水平会诱导参与膜转运和信号通路的基因以及对脂质稳态调节至关重要的 microRNA 的甲基化差异。增加胆碱水平也会影响参与脂肪酸生物合成和转运、脂肪分解和脂肪生成的基因，以及重要的免疫基因。我们的观察结果证实了胆碱在大西洋鲑中的表观遗传调控中的作用，正如在高等脊椎动物中所报道的那样。本研究表明，在研究中必须包括对大西洋鲑饲料中胆碱最佳水平进行定义的研究中，需要包括对表观遗传过程的生物标志物的研究。
