Abstract: 【Aim】Apterous (Ap) is a developmental regulatory protein belonging to the LIM domain family. This study aims to elucidate the role of the Ap gene in the wing development of the white-backed planthopper, Sogatella furcifera. 【Methods】 Based on the genome and transcriptome databases of S. furcifera, the cDNA sequence of SfAp was verified by RT-PCR and subjected to bioinformatic analysis. RT-qPCR was used to detect the expression levels of SfAp in different developmental stages (1st－5th instar nymphs, and female and male adults) and various adult tissues (head, thorax, abdomen, leg, wing, integument, fat body and gut) of S. furcifera. The growth and development of S. furcifera were observed after silencing SfAp in the 3rd instar nymphs using RNAi, and the survival rate, total mortality rate, and wing deformity rate after RNAi were counted, while the expression levels of the key genes involved in wing development signaling pathways (bursicon genes SfBurs-α and SfBurs-β, Hippo signaling pathway genes SfHippo and SfSal, Wnt signaling pathway gene SfWg, Hedgehog signaling pathway genes SfHh and SfDpp, and SfHOW) were measured using RT-qPCR. 【Results】 The open reading frame of SfAp (GenBank accession no.: PP901867) of S. furcifera was cloned, with the length of 1 287 bp encoding a protein of 428 amino acids. The encoded protein has the predicted molecular weight of 47.41 kD and the theoretical isoelectric point of 8.99. SfAp has the conserved typical LIM domain. SfAp was closely related to NlAp of Nilaparvata lugens, and their amino acid sequence identity was 84.86%. Developmental expression profile result revealed that SfAp exhibited high expression levels before the 4th instar nymph followed by a gradual decline, a significant increase on the 3rd day of the 5th instar nymph, and a subsequent decrease after adult eclosion. Tissue expression profile result showed that the expression level of SfAp in the adult thorax was the highest, followed by those in the abdomen, fat body, and gut. Microinjection of dsSfAp resulted in the impaired wing extension and wing deformation of the eclosed adults, and significantly suppressed the expression of the wing development-related genes SfBurs-α, SfBurs-β, SfHippo, SfSal, SfWg, SfHh, SfDpp and SfHOW. 【Conclusion】 SfAp influences wing expansion and development of S. furcifera by modulating the expression levels of the key genes involved in the wing development signaling pathway.

Key words: Sogatella furcifera, LIM domain family, developmental regulatory protein, Ap gene, expression profiling, wing development