Abstract: 【Aim】 The Drosophila Dichaete gene is a gene of Sox B subfamily, which is expressed throughout embryogenesis and plays an important role in early development. Dichaete also exists in the leg disc of larvae, but little is known about its function in legs. The aim of this study is to investigate the effect of ectopic expression of Dichaete on leg development of Drosophila and to explore the underlying mechanism. 【Methods】en-Gal4 and UAS-Dichaete of Drosophila melanogaster were crossed, and Dichaete was ectopicly expressed under the control of en-Gal4 in the progeny. Legs of the progeny were cut off and their structure was observed using binocular microscope. Immunohistochemistry was used to detect cell apoptosis and Distal-less (Dll) expression in leg discs. 【Results】 The ectopic expression of Dichaete resulted in distal leg defects of adults, enhanced apoptosis in the 3rd instar larvae, and increased expression of distal-less in D. melanogaster, but had no effect on Wg and Dpp signaling activities. Inhibition of apoptosis could not rescue the leg defects. 【Conclusion】 Ectopic expression of Dichaete interferes with maintenance of distal-less gene, leading to structural defects of adult legof D. melanogaster.

Key words: Drosophila melanogaster, Dichaete, ectopic expression, leg, apoptosis, Distal-less