Fruit fly phylogeny imprints bacterial gut microbiota

Area of Science:

• Ecology
• Microbiology
• Evolutionary Biology

Background:

• Insect gut microbiota influence host fitness, impacting development, immunity, nutrition, and behavior.
• Understanding the factors that determine gut microbiota composition, such as host phylogeny and ecology, is crucial but remains poorly understood.

Purpose of the Study:

• To investigate the contributions of fruit fly phylogeny, ecological specialization, and sampling environment to the composition and structure of their gut bacterial microbiota.
• To analyze a community of eight sympatric fruit fly species from the Tephritidae family, including specialists and generalists.

Main Methods:

• 16S metabarcoding using Oxford Nanopore Technology to generate bacterial genus-level inventories.
• Analysis of bacterial community composition and structure using network-based clustering techniques.
• Comparison of field and laboratory samples for each fly species.

Main Results:

• Gut microbiota were dominated by the Enterobacteriaceae family across all samples.
• Microbial profiles varied significantly based on fly identity and sampling environment.
• Alpha diversity differed between fly tribes, with Dacinae showing higher diversity than Ceratitinae.
• Network analyses revealed strong congruence between microbial profiles and host phylogeny, with sampling environment as a significant modulator.
• Fly specialization had a minimal impact on gut microbiota composition.

Conclusions:

• Host phylogeny is a primary determinant of gut microbiota composition in sympatric fruit flies, even when sharing host plants.
• The findings suggest significant host control over gut microbiota, likely through vertical transmission and/or environmental filtering.
• Sampling environment also plays a notable role in modulating microbial community structure.