Lyu Zihao, Chen Jingxiang, Li Zhixing, Cheng Jie, Wang Chunyan, Lin Tong
College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China.
Arch Insect Biochem Physiol. 2019 Aug;101(4):e21561. doi: 10.1002/arch.21561. Epub 2019 Jun 19.
β-N-acetylglucosaminidase (NAG) is a key enzyme in insect chitin metabolism and plays an important role in many physiological activities of insects. The HvNAG1 gene was identified from the Heortia vitessoides Moore (Lepidoptera: Crambidae) cDNA library and its expression patterns were determined using quantitative real-time polymerase chain reaction. The results indicated that HvNAG1 mRNA levels were high in the midgut and before molting, and 20E could induce its expression. Subsequently, the HvNAG1 gene was knocked down via RNA interference to identify its functions. We found that 3 μg of dsNAG1 resulted in optimal interference at 48 and 72 hr after injection, causing a decrease in NAG1 protein content, which resulted in abnormal or lethal phenotypes, and a sharp decrease in the survival rate. These results indicate that HvNAG1 plays a key role in the molting process of H. vitessoides. However, the silencing of HvNAG1 had no significant effect on the chitin metabolism-related genes tested in this study. Our present study provides a reference for further research on the utility of key genes involved in the chitin metabolic pathway in the insect molting process.
β-N-乙酰氨基葡萄糖苷酶（NAG）是昆虫几丁质代谢中的关键酶，在昆虫的许多生理活动中发挥重要作用。从大螟（鳞翅目：草螟科）的cDNA文库中鉴定出HvNAG1基因，并使用定量实时聚合酶链反应确定其表达模式。结果表明，HvNAG1 mRNA水平在中肠和蜕皮前较高，并且20E可以诱导其表达。随后，通过RNA干扰敲低HvNAG1基因以鉴定其功能。我们发现，注射3μg dsNAG1在注射后48和72小时导致最佳干扰，导致NAG1蛋白含量降低，这导致异常或致死表型，以及存活率急剧下降。这些结果表明，HvNAG1在大螟的蜕皮过程中起关键作用。然而，HvNAG1的沉默对本研究中测试的几丁质代谢相关基因没有显著影响。我们目前的研究为进一步研究几丁质代谢途径中的关键基因在昆虫蜕皮过程中的作用提供了参考。
