Genome-wide in vitro and in vivo RNAi screens reveal Fer3 to be an important regulator of kkv transcription in Drosophila


Xiangzhao Yue, Yongkang Liang, Zhishuang Wei, Jun Lv, Yongjin Cai, Xiaobin Fan, Wenqing Zhang, and Jie Chen. 2021. “Genome-wide in vitro and in vivo RNAi screens reveal Fer3 to be an important regulator of kkv transcription in Drosophila.” Insect Sci.


Krotzkopf verkehrt (kkv) is a key enzyme that catalyzes the synthesis of chitin, an important component of the Drosophila epidermis, trachea, and other tissues. Here, we report the use of comprehensive RNA interference (RNAi) analyses to search for kkv transcriptional regulators. A cell-based RNAi screen identified 537 candidate kkv regulators on a genome-wide scale. Subsequent use of transgenic Drosophila lines expressing RNAi constructs enabled in vivo validation, and we identified six genes as potential kkv transcriptional regulators. Weakening of the kkvDsRed signal, an in vivo reporter indicating kkv promoter activity, was observed when the expression of Akirin, NFAT, 48 related 3 (Fer3), or Autophagy-related 101(Atg101) was knocked down in Drosophila at the 3rd-instar larval stage; whereas we observed disoriented taenidial folds on larval tracheae when Lines (lin) or Autophagy-related 3(Atg3) was knocked down in the tracheae. Fer3, in particular, has been shown to be an important factor in the activation of kkv transcription via specific binding with the kkv promoter. The genes involved in the chitin synthesis pathway were widely affected by the downregulation of Fer3. Furthermore, Atg101, Atg3, Akirin, Lin, NFAT, Pnr and Abd-A showed the potential complex mechanism of kkv transcription are regulated by an interaction network with bithorax complex components. Our study revealed the hitherto unappreciated diversity of modulators impinging on kkv transcription and opens new avenues in the study of kkv regulation and chitin biosynthesis. This article is protected by copyright. All rights reserved.
Last updated on 08/09/2021