Sequencing and Analysis of Chicken Segmented Filamentous Bacteria Genome Revealed Unique Avian-Specific Features

Area of Science:

• Microbiology
• Genomics
• Immunology

Background:

• Segmented filamentous bacteria (SFB) are key gut microbes influencing host immunity, with known host-specific adaptations.
• Previous SFB genome studies focused on mammals, leaving avian SFB genomes largely uncharacterized.
• Understanding avian SFB is crucial for improving gut health and immune maturation in poultry.

Purpose of the Study:

• To perform metagenomic reconstruction and annotation of SFB genomes from chickens and turkeys.
• To investigate the genetic and metabolic adaptations of avian SFB.
• To identify novel SFB factors involved in host interaction and immune modulation.

Main Methods:

• Metagenomic reconstruction of SFB genome from chicken ileum using Hi-C sequencing.
• Reference-guided consensus assembly and Hi-C scaffolding for high-quality genome assembly.
• Pangenomic analysis, metabolic network analysis, and identification of specific genes like flagellin.

Main Results:

• High-quality genome assembly of Lohmann Select Leghorn (LSL)-SFB and annotation of avian SFB.
• Identification of a distinct gene repertoire in chicken and turkey SFB compared to mammalian strains.
• Demonstrated reduced biosynthetic capacity in avian SFB, indicating host reliance.
• Discovery of a unique flagellin subunit (fliC-2) in chicken SFB interacting with Toll-like receptor 5.

Conclusions:

• This study provides the first comprehensive genome data for chicken and turkey SFB.
• Avian SFB possess unique adaptations for host specificity and nutrient acquisition.
• The findings enhance our understanding of SFB-host interactions and their impact on avian intestinal health and immunity.