Hybrid capture RNA-seq defines temporal gene expression in Rickettsia.

Area of Science:

• Microbiology
• Genomics
• Molecular Biology

Background:

• Rickettsia species are obligate intracellular bacteria with poorly understood gene regulatory networks.
• Transcriptional profiling of Rickettsia is challenging due to host RNA contamination, especially during early infection stages.
• Existing methods limit comprehensive analysis of dynamic gene expression changes during Rickettsia infection.

Purpose of the Study:

• To adapt and apply the pathogen hybrid capture (PatH-Cap) method for Rickettsia transcriptional analysis.
• To investigate temporal gene expression trends during the first 24 hours of Rickettsia infection.
• To establish a comprehensive analysis of Rickettsia gene expression for future research.

Main Methods:

• Adapted the pathogen hybrid capture (PatH-Cap) technique for Rickettsia species.
• Enriched bacterial transcripts and depleted host/rRNA molecules for improved library preparation.
• Performed transcriptional profiling throughout the first 24 hours of infection, including infection initiation.

Main Results:

• Identified temporal expression trends for gene cohorts, including those involved in growth and pathogenesis.
• Revealed diverse temporal expression patterns for translation, cell division, secreted effectors, and secretion system components.
• Discovered 639 antisense RNA molecules, many exhibiting significant temporal expression trends.

Conclusions:

• PatH-Cap is a sensitive method for dissecting gene expression in intracellular pathogens.
• This study provides the most comprehensive temporal gene expression analysis of Rickettsia to date.
• The findings lay the groundwork for future studies on Rickettsia gene regulation under various conditions.