关键词: 果蝇, 转基因, 靶基因, 翅芽; wingless, 表达水平, 温度

Abstract:  【Aim】 Flexibly controlling the expression levels of target genes is critical for the study of gene function. Gal4/UAS system has been intensively used to manipulate gene expression and to study complex biological problems of model organisms such as Drosophila. Affected by the properties of transposon vector constructs and the insertion site in the transgenic stock, the ability of Gal4 or UAS transgenic lines to regulate target genes is roughly predefined after construction. This study aims to develop a new strategy based on the conventional GAL4/UAS system to flexibly modulate the expression level of wingless (wg) gene in Drosophila wing discs. 【Methods】 UAS-wg and UAS-wg-RNAi transgenes of Drosophila melanogaster were recombined into the same D. melanogaster line by genetic approach. And this line was crossed with dpp-Gal4 line to co-express UAS-wg and UAS-wg-RNAi in larval wing discs. The progeny larvae were cultured at different temperatures (18, 25 and 30℃). The larval wing discs were dissected and stained by immunohistochemistry. The fluorescence intensity was measured to analyze the expression level of wg in the wing discs. 【Results】 UAS-wg played a dominant role in the regulation of gene expression at low temperature (18℃). In this case, the efficiency of overexpression of wg was attenuated effectively by UAS-wg-RNAi. On the contrary, UAS-wg-RNAi predominated in the regulation of gene expression, and the expression of wg was inhibited at high temperature (30℃). Besides, by switching temperature, the wg expression could be transformed between overexpression and repression in wing disc at different developmental stages, and the expression of wg could be modulated flexibly in wing disc. 【Conclusion】 By this approach, we can flexibly modulate the expression of wg in wing disc of Drosophila. It has great significance in target gene regulation.

Key words: Drosophila, transgene, target gene, wing disc, wingless; expression level, temperature