The production of docosahexaenoic acid (DHA) in transgenic plants: a sustainable source of omega-3 fish oils

鱼油历来与有益健康的特性联系在一起，在过去的几年里，大量的科学研究已经证明了富含鱼油的饮食的好处。特别是，鱼油中发现的一些脂肪酸似乎在预防心脏病发作和其他循环系统问题方面发挥作用。这些脂肪酸是omega-3长链多不饱和脂肪酸（简称omega-3 LC-PUFAs），它们现在被广泛认为是人类饮食的重要组成部分。鱼油omega-3 LC-PUFAs不仅能够预防疾病，对人体生长发育也非常重要。例如，母乳含有这些脂肪酸，正因为如此，配方奶（替代奶）现在富含这些脂肪。omega-3 LC-PUFAs的主要来源是鱼油，但不幸的是，全球鱼类资源现在严重下降（主要是由于几十年来的过度捕捞）。这不仅代表了一场生态危机，而且可能在未来严重妨碍维持健康饮食所需的鱼油的供应。此外，人们越来越担心目前的野生鱼类种群受到重金属、增塑剂和二恶英等污染物的污染。因此，迫切需要找到这些非常重要的脂肪酸的新的可持续来源。我们正在尝试的一种方法是在植物中制造鱼油。这需要一种合适的植物（最好是油籽）的基因工程，因为目前还没有已知的高等植物合成omega-3 LC-PUFAs的例子。为了开展这项工作，需要在植物中引入指导omega-3 LC-PUFAs合成的基因。这些基因来自生活在海洋中的微小微生物（如藻类），它们可以合成omega-3 LC-PUFAs，因此该项目需要将这些基因转移到植物中，以便以清洁和可持续的方式合成这些重要的脂肪酸。

Fish oils have been historically associated with health-beneficial properties and over the last few years a large number of scientific studies have demonstrated the benefits of a diet rich in these oils. In particular, some of the fatty acids found in fish oils seem to play a role in preventing heart attacks and other circulatory problems. These fatty acids are the omega-3 long chain polyunsaturated fatty acids (abbreviated to omega-3 LC-PUFAs), and they are now widely viewed as vital constituents of human diet. As well as being able to play a role in preventing diseases, fish oil omega-3 LC-PUFAs are also very important in human growth and development. For example, breast milk contains these fatty acids, and it is for this reason formula (replacement) milks are now enriched in these fats. The primary source of omega-3 LC-PUFAs is fish oils, but unfortunately global fish stocks are now in severe decline (mainly due to decades of over-fishing). This not only represents an ecological crisis, but may also, in the future, severely hamper the availability of fish oils to maintain a healthy diet. Moreover, there are growing concerns about the contamination of current wild fish stocks with pollutants such as heavy metals, plasticizers and dioxins. Therefore, there is an urgent need to find a new sustainable source of these very important fatty acids. One approach that we are undertaking is to try and make fish oils in plants. This requires genetic engineering of a suitable plant (ideally an oilseed), because there are no known examples of higher plants which synthesise omega-3 LC-PUFAs. To carry out this work, the genes which direct the synthesis of omega-3 LC-PUFAs need to be introduced in a plant. These genes come from the tiny microbes (such as algae) which live in the ocean and synthesise omega-3 LC-PUFAs, so the project involves moving these genes into plants, to allow the synthesis of these important fatty acids in a clean and sustainable manner.