Enterobacter hormaechei promotes the growth and development of Drosophila melanogaster

Abstract:

[Background] Commensal bacteria can affect host’s physiology, metabolism and neural behavior. Drosophila melanogaster is an excellent genetic model to investigate the mechanism of interaction between host and commensal bacteria. [Objective] To isolate and identify the commensal bacteria from D. melanogaster, and investigate their effects on the growth and development of D. melanogaster. [Methods] The YG agar medium was prepared to isolate bacteria from the intestinal tract of D. melanogaster. Gram-staining, biochemical identification and 16S rRNA gene blast were used to identify the bacteria strain. The commensalism between the bacteria and D. melanogaster was verified by colonization and generation transfer experiments. The sterile and gnotobiotic animal models were established to verify the growth promotion effect of E. hormaechei through the development timing and growth rate. RT-PCR was used to examine the molecular markers; immunofluorescence staining monitored proliferation of intestinal cells in fruit flies. [Results] A bacterial strain that could robustly promote the growth of the flies was isolated from the gut of D. melanogaster and identified as E. hormaechei. It stably colonized the gut of D. melanogaster and medium, and could be delivered to descendant. E. hormaechei promoted the growth of the flies obviously via increasing PTTH secretion and promoting the proliferation of intestinal cells in fruit flies. E. hormaechei decreased the level of glucose compared to germ-free flies. [Conclusion] E. hormaechei is a beneficial commensal bacterium of D. melanogaster to promote the growth and development of D. melanogaster.

Key words:Drosophila melanogaster, Enterobacter hormaechei, Commensal bacteria, Growth, Development