Comparative transcriptomics reveals the molecular toolkit used by an algivorous protist for cell wall perforation

Area of Science:

• Microbiology
• Molecular Biology
• Biochemistry

Background:

• Microbial eukaryotes exhibit diverse feeding strategies, including specialized
• protoplast feeders
• that consume prey cell contents after penetrating cell walls.

Purpose of the Study:

• To investigate the molecular mechanisms underlying cell wall penetration by the protoplast feeder Orciraptor agilis.
• To identify enzymes and genetic factors involved in the dissolution of green algal cell walls.

Main Methods:

• Differential gene expression analysis of Orciraptor agilis during algal cell wall attack.
• Bioinformatic identification and characterization of candidate enzymes.

Main Results:

• Upregulation of lytic carbohydrate-active enzymes, including a prominent endocellulase (GH5_5), during prey cell wall penetration.
• Discovery of uncharacterized enzyme families, such as lytic polysaccharide monooxygenases.
• Identification of novel chitin-related factors suggesting an unknown chitin metabolism in Orciraptor agilis.

Conclusions:

• The study provides the first molecular insights into the feeding behavior of protoplast feeders.
• Identified enzymes offer new avenues for exploring enzyme discovery in non-model microeukaryotes.
• The findings open new directions for cell biology research on microbial feeding strategies.