State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou 310058, China; Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou 310058, China; Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
Gene. 2020 May 5;737:144446. doi: 10.1016/j.gene.2020.144446. Epub 2020 Feb 5.
The homeotic complex (Hox) gene Ultrabithorax (Ubx) plays pivotal roles in modifying specific morphological differences among the second (T2), the third thoracic (T3), and the first abdomen (A1) segment in several insects. Whether Ubx regulates wing dimorphism and other morphological traits in the delphacid family (order Hemiptera) remains elusive. In this study, we cloned a full-length Ubx ortholog (NlUbx) from the wing-dimorphic planthopper Nilaparvata lugens, and identified two NlUbx isoforms. RNA-interference (RNAi)-mediated silencing of NlUbx in short-winged BPH nymphs significantly induced the development of wing-like appendages from T3 wingbuds, and this effect is likely mediated by the insulin/insulin-like signaling pathway. RNAi knockdown of NlUbx in long-winged BPH nymphs led to a transformation from hindwings to forewings. Additionally, silencing of NlUbx not only dramatically changed the T3 morphology, but also led to jumping defect of T3 legs. First-instar nymphs derived from parental RNAi had an additional leg-like appendages on A1. These results suggest that Ubx plays a role in determining some morphological traits in delphacid planthoppers, and thus help in understanding evolution of morphological characteristics in arthropods.
同源异型复合体（Hox）基因 Ultrabithorax（Ubx）在几种昆虫中对第二（T2）、第三胸（T3）和第一腹（A1）节的特定形态差异的修饰中起着关键作用。Ubx 是否调节半翅目（Hemiptera 目）飞虱科中的翅膀二型性和其他形态特征仍不清楚。在这项研究中，我们从具有翅膀二型性的褐飞虱 Nilaparvata lugens 中克隆了全长 Ubx 直系同源物（NlUbx），并鉴定了两种 NlUbx 异构体。短翅型 BPH 若虫中 NlUbx 的 RNA 干扰（RNAi）介导的沉默显著诱导了 T3 翅芽发育出翅膀状附肢，这种效应可能是由胰岛素/胰岛素样信号通路介导的。长翅型 BPH 若虫中 NlUbx 的 RNAi 敲低导致后翅转化为前翅。此外，NlUbx 的沉默不仅显著改变了 T3 的形态，还导致 T3 腿的跳跃缺陷。来自亲代 RNAi 的第一龄若虫在 A1 上有一个额外的腿状附肢。这些结果表明 Ubx 在决定飞虱科某些形态特征方面起着作用，从而有助于理解节肢动物形态特征的进化。
