Molecular basis for interactions between protists and other organisms: How protists recognize and capture prey cells

Since protists are single-celled organisms, one might think that these organisms live a solitary life, independent of other organisms. In reality, however, many protists develop complex interrelationships with other unicellular and multicellular organisms. For example, predatory protists recognize and capture other organisms as prey. On the other hand, to escape from predators, they need to recognize their enemies correctly. Some protists recognize cells of the same species of different cell types for sexual reproduction. Some are symbiotic with other eukaryotes or prokaryotes in their cells, and some are symbiotic in the bodies of other larger organisms. There are also protozoa that can infect animals and cause disease. Recent studies have revealed the mechanisms by which protists recognize other organisms. As a result, we have gained many unique insights into the molecular mechanisms of cellular interactions between protists and other organisms, and the aspects of biological evolution driven by these interactions. This review provides an overview of the latest research findings on cell-cell interactions in protist prey recognition, with a particular focus on their molecular and evolutionary perspectives.