Many invertebrate species possess the metabolic ability to synthesize long-chain ω3 polyunsaturated fatty acids (PUFA) de novo. Due to their diverse effects on membrane architecture, neuroplasticity, growth and reproduction, PUFA have a high potential to positively influence the fitness of an organism. But how and when do these supposed advantages actually come into play? Other species, that are often closely related, pass natural selection without this special metabolic ability. The ω3-PUFA rich model organism Caenorhabditis elegans (Nematoda) and its mutant fat-1(wa9), lacking these PUFA, are a suitable test system. We analyzed potential impairments in reproduction and growth in a soil assay. Further, chemotaxis after aversive olfactory, associative learning and integration of a second sensory signal were assessed on agar plates. Moreover, we analyzed the phospholipid pattern of both C. elegans strains and further free-living nematodes species at different temperatures. While the phenotypic effects were rather small under standard conditions, lowering the temperature to 15 or even 10 °C or reducing the soil moisture, led to significant limitations, with the investigated parameters for neuroplasticity being most impaired. The ω3-PUFA free C. elegans mutant strain fat-1 did not adapt the fatty acid composition of its phospholipids to a decreasing temperature, while ω3-PUFA containing nematodes proportionally increased this PUFA group. In contrats, other ω3-PUFA free nematode species produced significantly more ω6-PUFA. Thus, the ability to synthesize long-chain ω3-PUFA de novo likely is fundamental for an increase in neuroplasticity and an efficient way for regulating membrane fluidity to maintain their functionality.

许多无脊椎动物物种具有从头合成长链ω3多不饱和脂肪酸（PUFA）的代谢能力。由于多不饱和脂肪酸对膜结构、神经可塑性、生长和繁殖具有多种影响，因此具有对生物体健康产生积极影响的巨大潜力。但这些所谓的优势如何以及何时真正发挥作用呢？其他通常密切相关的物种在没有这种特殊代谢能力的情况下通过了自然选择。富含 ω3-PUFA 的模式生物秀丽隐杆线虫(Nematoda) 及其缺乏这些 PUFA 的突变体fat-1(wa9)是合适的测试系​​统。我们通过土壤测定分析了繁殖和生长的潜在损害。此外，在琼脂平板上评估厌恶嗅觉后的趋化性、联想学习和第二感觉信号的整合。此外，我们分析了线虫菌株和其他自由生活的线虫物种在不同温度下的磷脂模式。虽然在标准条件下表型效应相当小，但将温度降低至 15 甚至 10 °C 或降低土壤湿度会导致显着的限制，所研究的神经可塑性参数受到最大程度的损害。不含 ω3-PUFA 的线虫突变株fat-1并未调整其磷脂的脂肪酸组成以适应A温度降低，而含有线虫的 ω3-PUFA 则按比例增加了该 PUFA 组。相比之下，其他不含 ω3-PUFA 的线虫物种产生明显更多的 ω6-PUFA。因此，从头合成长链 ω3-PUFA 的能力可能是增加神经可塑性的基础，也是调节膜流动性以维持其功能的有效方法。