Coat protein I genes are essential for the morphogenesis of the intestinal tract in Locusta migratoria

Abstract

The coat protein I (COPI) complex is crucial in several significant physiological processes in eukaryotes. The assembly of COPI vesicles is initiated by the recruitment of adenosine diphosphate-ribosylation factor 1 (Arf1) to the membrane. Previous studies have primarily focused on the roles of COPI in yeast, humans, insects, and beyond Drosophila. However, the function of COPI during the development of insects remains largely unknown. In this study, we first identified eight COPI assembly genes, including α-, β-, β'-, γ-, δ-, ε-, ζ-COPI, and Arf1 in Locusta migratoria. Quantitative reverse-transcription polymerase chain reaction revealed that these genes were uniformly expressed in multiple tissues, including wing pads, leg, foregut, midgut, hindgut, and gastric cecum, and on all developmental days in 5th-instar nymphs. The injection of double-stranded RNAs (dsRNAs) against LmCOPI and LmArf1 induced high silencing efficiency in the 3rd- and 5th-instar nymphs. Locusts treated with dsLmCOPIs and dsLmArf1 exhibited feeding cessation, leading to 100 % mortality. LmCOPIs and LmArf1 knockdown resulted in midgut and gastric cecum atrophy. Histological observation and hematoxylin-eosin staining indicated that the midgut and gastric cecum exhibited deformed structures, with defective microvilli and midgut peritrophic matrix. These results suggest that LmCOPIs and LmArf1 significantly affect the intestinal tract morphogenesis in locust nymphs. Thus, COPI assembly genes are promising RNA interference targets for managing L. migratoria, reducing the dependence on chemical pesticides for pest control.