Covariation between microeukaryotes and bacteria associated with Planorbidae snails

Area of Science:

• Microbiology
• Eukaryotic Ecology
• Bioinformatics

Background:

• Microbial communities impact host health, but microeukaryotic diversity and interactions with bacteria in hosts are poorly understood.
• Bacteria associated with macroorganisms are well-studied, contrasting with the limited knowledge of microeukaryotes.

Purpose of the Study:

• To characterize microeukaryotic communities in Planorbidae snails.
• To investigate the covariation between microeukaryotic and bacterial communities within snail hosts.
• To develop a method for studying microeukaryote diversity in host-associated microbiota.

Main Methods:

• Developed a blocking primer to minimize host DNA amplification during metabarcoding.
• Analyzed microeukaryotic diversity using 18S rRNA gene sequencing.
• Analyzed bacterial diversity using 16S rRNA gene sequencing.
• Computed alpha and beta diversities for both microbial groups.

Main Results:

• Microeukaryotes were dominated by three phyla (Amoebozoa, Opisthokonta, Alveolata), while bacteria showed higher diversity with five dominant phyla.
• Microeukaryote and bacterial community composition correlated in *Biomphalaria glabrata* but not in *Planorbarius metidjensis*.
• Network analysis revealed covarying taxa, suggesting potential top-down control of bacteria by microeukaryotes and inter-microeukaryote competition.

Conclusions:

• The developed blocking primer facilitates the study of previously hidden microeukaryotic diversity in snail microbiota.
• Findings highlight the potential for microeukaryotes to influence bacterial communities within snail hosts.
• Further research is needed to elucidate the roles and interactions of these microeukaryotes in host-microbe dynamics.