Abstract: 【Aim】To explore the functions and molecular mechanisms of the chromatin remodeling factor Toutatis (Tou) in the wing development of Drosophila melanogaster, so as to provide new insights into the regulatory network of insect wing development and identify potential molecular targets for manipulating the flight ability of agricultural pests.【Methods】Phylogenetic analysis was performed to evaluate the evolutionary conservation of Tou among insects. The expression levels of Tou in the egg stage, 24, 48, 72 and 84 h of the larval stage, and 24, 32, 40, 48, 56, 64 and 72 h of the prepupal stage, and in different tissues (imaginal disc, salivary gland, gut, fat body and Malpighian tubules) during the prepupal stage of D. melanogaster were examined by qRT-PCR. Using the GAL4/UAS system of D. melanogaster combined with RNAi technique, Tou expression was specifically knocked down in the wing imaginal discs. The expression changes of the cell proliferation marker phosphorylated histone H3 (pH3) and the axial developmental signaling factor Wingless (Wg) were observed by immunofluorescence staining. In addition, the adult wing area was measured to assess the effect of Tou on wing morphology. 【Results】Tou proteins are highly conserved across various insect species. The expression level of Tou peaked at 32 h of the prepupal stage and was highly expressed in the wing imaginal discs at the prepupal stage. After Tou knockdown, both the area of the female and male adult wings was significantly smaller than that of the control group, while the density of pH3-positive cells showed no significant change, suggesting a limited effect on cell proliferation. However, the normal spatial expression pattern of Wg signaling pathway genes was disrupted. 【Conclusion】This study reveals that Tou participates in wing axial development of D. melanogaster by regulating the spatiotemporal expression of the Wg signaling pathway genes, playing a crucial role in this process. These findings lay a foundation for further understanding the insect wing development and provide an experimental basis for future studies on the specific functions of Tou.

Key words: Drosophila melanogaster, chromatin remodeling factor, Toutatis, GAL4/UAS system, RNAi, wing area measurement, Wingless signaling pathway