Gut Bacterial Communities in the Ground Beetle Carabus convexus

Area of Science:

• Microbial ecology
• Insect biology
• Evolutionary biology

Background:

• Biological interactions, especially symbiotic ones, are crucial for ecological and evolutionary processes.
• The gut microbiome significantly impacts host fitness and competitiveness, but research on wild invertebrates, like ground beetles, is limited.
• Previous studies on the Carabus genus focused on Asian species, leaving a knowledge gap for European species.

Purpose of the Study:

• To investigate the gut bacterial microbiome of a widespread European Carabus species.
• To characterize the bacterial diversity and identify dominant taxa within the gut of C. convexus.
• To explore the potential functional role of identified symbionts in host nutrition.

Main Methods:

• Utilized next-generation high-throughput sequencing targeting the V3 and V4 regions of 16S ribosomal RNA genes.
• Analyzed the gut bacterial microbiome composition of wild C. convexus individuals.
• Identified operational taxonomic units (OTUs) and assigned them to bacterial phyla, families, and genera.

Main Results:

• Identified 1138 OTUs across 21 bacterial phyla, 90 families, and 197 genera.
• Prevotellaceae, a carbohydrate-degrading family, was the most abundant symbiont in the gut microbiome of C. convexus.
• This family had not been previously detected in ground beetles.

Conclusions:

• The gut microbiome of European Carabus species is diverse and dominated by novel bacterial symbionts.
• The abundance of Prevotellaceae suggests that C. convexus may consume and digest plant materials, such as fruits.
• These findings highlight the importance of gut symbionts in mediating host-diet interactions and host adaptation.