School of Biological Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
Biochem Biophys Res Commun. 2010 Mar 12;393(3):397-403. doi: 10.1016/j.bbrc.2010.01.130. Epub 2010 Feb 6.
Despite the known importance of long-chained polyunsaturated fatty acids (LC-PUFA) during development, very little is known about their utilization and biosynthesis during embryogenesis. Combining the advantages of the existence of a complete range of enzymes required for LC-PUFA biosynthesis and the well established developmental biology tools in zebrafish, we examined the expression patterns of three LC-PUFA biosynthesis genes, Elovl2-like elongase (elovl2), Elovl5-like elongase (elovl5) and fatty acyl desaturase (fad) in different zebrafish developmental stages. The presence of all three genes in the brain as early as 24 hours post fertilization (hpf) implies LC-PUFA synthesis activity in the embryonic brain. This expression eventually subsides from 72 hpf onwards, coinciding with the initiation of elovl2 and fad expression in the liver and intestine, 2 organs known to be involved in adult fish LC-PUFA biosynthesis. Collectively, these patterns strongly suggest the necessity for localized production of LC-PUFA in the brain during in early stage embryos prior to the maturation of the liver and intestine. Interestingly, we also showed a specific expression of elovl5 in the proximal convoluted tubule (PCT) of the zebrafish pronephros, suggesting a possible new role for LC-PUFA in kidney development and function.
尽管长链多不饱和脂肪酸 (LC-PUFA) 在发育过程中的重要性已为人所知，但人们对其在胚胎发生过程中的利用和生物合成知之甚少。结合存在完整的 LC-PUFA 生物合成所需酶和斑马鱼中成熟的发育生物学工具的优势，我们检查了三种 LC-PUFA 生物合成基因（Elovl2 样延长酶 (elovl2)、Elovl5 样延长酶 (elovl5) 和脂肪酸去饱和酶 (fad)）在不同斑马鱼发育阶段的表达模式。在受精后 24 小时 (hpf) 时，这三个基因都存在于大脑中，这意味着胚胎大脑中存在 LC-PUFA 合成活性。这种表达最终从 72 hpf 开始减弱，与肝脏和肠道中 elovl2 和 fad 表达的开始时间一致，肝脏和肠道是已知参与成年鱼类 LC-PUFA 生物合成的两个器官。总的来说，这些模式强烈表明，在肝脏和肠道成熟之前，胚胎早期大脑中需要局部产生 LC-PUFA。有趣的是，我们还在斑马鱼前肾的近端卷曲小管 (PCT) 中特异性表达了 elovl5，这表明 LC-PUFA 在肾脏发育和功能中可能有新的作用。
