A scaleable inducible knockout system for studying essential gene function in the malaria parasite.

Area of Science:

• Genetics
• Parasitology
• Molecular Biology

Background:

• Malaria parasites require numerous genes for survival within red blood cells.
• Studying essential gene functions necessitates inducible gene expression interference systems.
• Current DiCre-lox systems lack scalability for simultaneous analysis of multiple genes.

Purpose of the Study:

• To develop a scalable strategy for studying essential gene functions in malaria parasites.
• To overcome limitations of existing DiCre-lox systems for high-throughput genetic screening.
• To enable inducible phenotypic screening of multiple genes concurrently.

Main Methods:

• Developed SHIFTiKO (frameshift-based trackable inducible knockout), a novel scalable strategy.
• Utilized short, barcoded repair templates to insert loxP sites around target gene regions.
• Induced DiCre-mediated excision causing frameshift mutations for genetic ablation.
• Employed dual DNA barcodes for verification and collective phenotyping.

Main Results:

• Successfully applied SHIFTiKO to screen malarial rhomboid proteases.
• Identified blood stage-specific essentiality of screened rhomboid proteases.
• Demonstrated SHIFTiKO's capability for assessing growth fitness and specific impairments.

Conclusions:

• SHIFTiKO provides a powerful, scalable platform for inducible phenotypic screens in malaria parasites.
• Facilitates large-scale study of essential gene functions, crucial for understanding parasite biology.
• Aids in identifying critical genes for parasite propagation and potential therapeutic targets.