Li Haolin, Kong Xue, Fang Yan, Hou Jiangan, Zhang Wenjie, Zhang Yongheng, Wei Jiguang, Li Xuesheng
Guangxi Key Laboratory of Agric-Environment and Agric-Products Safety, College of Agriculture, Guangxi University, Nanning, China.
Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China.
Insect Sci. 2025 Aug;32(4):1311-1330. doi: 10.1111/1744-7917.13450. Epub 2024 Oct 4.
Juvenile hormones (JHs) play a crucial role in regulating development and reproduction in insects. Most insects predominantly synthesize JH III, which typically involves esterification followed by epoxidation, lepidopteran insects use a pathway of epoxidation followed by esterification. Although hemipteran insects have JH III and JH skipped bisepoxide III (JH SB3), the synthesis pathway and key epoxidases remain unclear. This study was conducted on Aphis craccivora, and demonstrated that corpora allata, microsomes, Ac-CYP15C1, and Ac-JHAMT catalyze JH III production in vitro, establishing the pathway of epoxidation followed by esterification. These findings were further confirmed through RNA interference and molecular docking. The presence of JH III and JH SB3 in A. craccivora was identified, and their synthesis pathway was elucidated as follows: Ac-CYP15C1 oxidizes farnesic acid to JH A, followed by methylation to JH III by Ac-JHAMT, possibly providing an epoxidation site on the second carbon for JH SB3. This alteration may significantly contribute to the differentiation and functional diversification of JH types in insects.
保幼激素（JHs）在调节昆虫的发育和繁殖中起着至关重要的作用。大多数昆虫主要合成JH III，其过程通常包括酯化，然后是环氧化，而鳞翅目昆虫则采用先环氧化后酯化的途径。虽然半翅目昆虫具有JH III和跳过双环氧的JH III（JH SB3），但其合成途径和关键环氧化酶仍不清楚。本研究以豆蚜为对象，证明了咽侧体、微粒体、Ac-CYP15C1和Ac-JHAMT在体外催化JH III的产生，确立了先环氧化后酯化的途径。这些发现通过RNA干扰和分子对接得到了进一步证实。确定了豆蚜中JH III和JH SB3的存在，其合成途径如下：Ac-CYP15C1将法尼酸氧化为JH A，随后由Ac-JHAMT甲基化为JH III，可能为JH SB3在第二个碳原子上提供了一个环氧化位点。这种改变可能对昆虫中JH类型的分化和功能多样化有显著贡献。
