Taipale Sami J, Kers Erwin, Peltomaa Elina, Loehr John, Kainz Martin J
Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35 (YA), 40014 Jyväskylä, Finland.
Lammi Biological Station, University of Helsinki, Pääjärventie 320, 16900 Lammi, Finland.
Biomolecules. 2021 Mar 23;11(3):478. doi: 10.3390/biom11030478.
Gammarid amphipods are a crucial link connecting primary producers with secondary consumers, but little is known about their nutritional ecology. Here we asked how starvation and subsequent feeding on different nutritional quality algae influences fatty acid retention, compound-specific isotopic carbon fractionation, and biosynthesis of ω-3 and ω-6 polyunsaturated fatty acids (PUFA) in the relict gammarid amphipod . The fatty acid profiles of closely matched with those of the dietary green algae after only seven days of refeeding, whereas fatty acid patterns of were less consistent with those of the diatom diet. This was mainly due to suffering energy limitation in the diatom treatment which initiated the metabolization of 16:1ω7 and partly 18:1ω9 for energy, but retained high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) similar to those found in wild-caught organisms. Moreover, α-linolenic (ALA) from green algae was mainly stored and not allocated to membranes at high levels nor biosynthesized to EPA. The arachidonic acid (ARA) content in membrane was much lower than EPA and was able to biosynthesize long-chain ω-6 PUFA from linoleic acid (LA). Our experiment revealed that diet quality has a great impact on fatty acid biosynthesis, retention and turnover in this consumer.
钩虾是连接初级生产者和次级消费者的关键环节，但对其营养生态学却知之甚少。在此，我们研究了饥饿及随后以不同营养质量的藻类为食，对残遗钩虾脂肪酸保留、化合物特异性碳同位素分馏以及ω-3和ω-6多不饱和脂肪酸（PUFA）生物合成的影响。再投喂仅七天后，[某种钩虾]的脂肪酸谱就与所投喂绿藻的脂肪酸谱高度匹配，而[另一种钩虾]的脂肪酸模式与硅藻饲料的脂肪酸模式不太一致。这主要是因为[后一种钩虾]在硅藻处理组中受到能量限制，启动了16:1ω7和部分18:1ω9的代谢以获取能量，但仍保留了与野生捕获生物中相似的高水平二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）。此外，绿藻中的α-亚麻酸（ALA）主要被储存，没有大量分配到细胞膜中，也没有生物合成EPA。细胞膜中的花生四烯酸（ARA）含量远低于EPA，[该种钩虾]能够从亚油酸（LA）生物合成长链ω-6 PUFA。我们的实验表明，食物质量对这种消费者的脂肪酸生物合成、保留和周转有很大影响。
