Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, People's Republic of China.
PLoS One. 2013 Aug 19;8(8):e71970. doi: 10.1371/journal.pone.0071970. eCollection 2013.
UDP-N-acetylglucosamine pyrophosphorylases (UAP) function in the formation of extracellular matrix by producing N-acetylglucosamine (GlcNAc) residues needed for chitin biosynthesis and protein glycosylation. Herein, we report two UAP cDNA's derived from two different genes (LmUAP1 and LmUAP2) in the migratory locust Locusta migratoria. Both the cDNA and their deduced amino acid sequences showed about 70% identities between the two genes. Phylogenetic analysis suggests that LmUAP1 and LmUAP2 derive from a relatively recent gene duplication event. Both LmUAP1 and LmUAP2 were widely expressed in all the major tissues besides chitin-containing tissues. However, the two genes exhibited different developmental expression patterns. High expression of LmUAP1 was detected during early embryogenesis, then decreased greatly, and slowly increased before egg hatch. During nymphal development, the highest expression of LmUAP1 appeared just after molting but declined in each inter-molting period and then increased before molting to the next stage, whereas LmUAP2 was more consistently expressed throughout all these stages. When the early second- and fifth-instar nymphs (1-day-old) were injected with LmUAP1 double-stranded RNA (dsRNA), 100% mortality was observed 2 days after the injection. When the middle second- and fifth-instar nymphs (3- to 4-day-old) were injected with LmUAP1 dsRNA, 100% mortality was observed during their next molting process. In contrast, when the insects at the same stages were injected with LmUAP2 dsRNA, these insects were able to develop normally and molt to the next stage successfully. It is presumed that the lethality caused by RNAi of LmUAP1 is due to reduced chitin biosynthesis of the integument and midgut, whereas LmUAP2 is not essential for locust development at least in nymph stage. This study is expected to help better understand different functions of UAP1 and UAP2 in the locust and other insect species.
UDP-N-乙酰氨基葡萄糖焦磷酸化酶（UAP）通过产生几丁质生物合成和蛋白质糖基化所需的 N-乙酰氨基葡萄糖（GlcNAc）残基，在细胞外基质的形成中发挥作用。在此，我们报告了从迁飞蝗Locusta migratoria 中的两个不同基因（LmUAP1 和 LmUAP2）中衍生的两个 UAP cDNA。这两个 cDNA 及其推导的氨基酸序列在两个基因之间显示出约 70%的同一性。系统发育分析表明，LmUAP1 和 LmUAP2 源自相对较近的基因复制事件。除含几丁质组织外，LmUAP1 和 LmUAP2 在所有主要组织中均广泛表达。然而，这两个基因表现出不同的发育表达模式。LmUAP1 的高表达在早期胚胎发生期间被检测到，然后大大降低，然后在卵孵化前缓慢增加。在若虫发育过程中，LmUAP1 的最高表达出现在蜕皮后，但在每个蜕皮期之间下降，然后在蜕皮到下一阶段之前增加，而 LmUAP2 在所有这些阶段都表现出更一致的表达。当早期第二龄和第五龄若虫（1 日龄）被注射 LmUAP1 双链 RNA（dsRNA）时，注射后 2 天观察到 100%的死亡率。当中期第二龄和第五龄若虫（3 至 4 日龄）被注射 LmUAP1 dsRNA 时，在它们的下一次蜕皮过程中观察到 100%的死亡率。相比之下，当处于相同阶段的昆虫被注射 LmUAP2 dsRNA 时，这些昆虫能够正常发育并成功蜕皮到下一阶段。据推测，RNAi 导致 LmUAP1 致死是由于表皮和中肠的几丁质生物合成减少，而 LmUAP2 在至少在若虫阶段对蝗虫的发育不是必需的。本研究有望帮助更好地理解 UAP1 和 UAP2 在蝗虫和其他昆虫物种中的不同功能。
