Abstract: The germ free and gnotobioticDrosophilamelanogastersystem was constructed, and the effects of different gut microbes on the mating behavior of germ free and conventionalD. melanogasterwere studied. The fertilized eggs ofD. melanogasterwere sterilized in vitro and cultured in sterile condition to obtain germ freeDrosophila.Lactobacillus plantarum,Acetobacterium malorumandSaccharomyces cerevisiaewere inoculated in fly culture medium, respectively, then the germ free and conventional flieswas kept respectively in the culture medium for a certain period of time to obtain different gnotobioticDrosophila.All flies were dissected and the total RNA of the gut was extracted and reverse transcribed, and the abundance of different microbes in the gut of germ free and conventional flies was detected by quantitative real-time PCR (qRT-PCR). Meanwhile, single pair mating assays were carried out to compare the copulation success rate and copulation latency of different treated flies. The results showed that the germ free and gnotobioticDrosophilasystem was successfully constructed, and the specific microbe was successfully enriched in the gut of the germ free and conventional flies after co-cultivation with the single microbe, andL. plantarumcould affect the mating behavior ofDrosophilaby prolonging the copulation latency.

Key words: Drosophilamelanogaster, germ free, gut microbe, copulation, qRT-PCR