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Quasi-metagenomic Analysis of Salmonella from Food and Environmental Samples
Published on: October 25, 2018
Genomic comparison between Salmonella Gallinarum and Pullorum: differential pseudogene formation under common host
Ye Feng1, Randal N Johnston, Gui-Rong Liu
1Genomics Research Center (one of The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, China.
Plos One
|April 5, 2013
Summary
Host restriction rapidly drives genomic degradation in Salmonella, leading to pseudogene formation. This study compares Salmonella Gallinarum and Pullorum, revealing significant genomic differences due to poultry adaptation.
Area of Science:
- Microbiology
- Genomics
- Evolutionary Biology
Background:
- Salmonella Enteritidis is host-promiscuous, while Salmonella Gallinarum is poultry-restricted.
- Salmonella Gallinarum shows extensive genomic degradation compared to Enteritidis.
- Salmonella Gallinarum comprises two biovars: Gallinarum (typhoid) and Pullorum (dysentery), both poultry-specific.
Purpose of the Study:
- Investigate the evolutionary processes behind host-restricted Salmonella pathogens.
- Compare genomic pseudogenes of Salmonella Gallinarum and Pullorum to understand host adaptation.
- Elucidate the role of host restriction in Salmonella genomic evolution.
Main Methods:
- Sequenced the complete genome of Salmonella Pullorum strains.
- Compared gene and pseudogene content of Gallinarum, Pullorum, and other Salmonella lineages.
- Analyzed pseudogene inactivation mutations to infer functional loss.
Main Results:
- Gallinarum and Pullorum share similar gene content but differ significantly in pseudogenes.
- Shared pseudogenes in Gallinarum and Pullorum, intact in Enteritidis, suggest ancestral poultry restriction.
- Unique or differently inactivated pseudogenes reflect adaptation to poultry-specific functions.
Conclusions:
- Host restriction initiated and facilitated the divergence of Gallinarum and Pullorum.
- Pseudogene formation, not gene deletion, is the primary mode of genomic degradation.
- Host restriction causes rapid and substantial genomic degradation in Salmonella, continuing to shape its evolution.
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