Figure 4. Benefits of social behavior.

(A) Cell density signaling mechanisms enable synchronization of cellular activities thus preserving group level behaviors (blue circles) for when they are most advantageous. Additionally, not all individuals are equally receptive to the signals thus allowing for differentiation within a population (white among blue circles). (B) Cell-cell communication and cooperative motility facilitate colonization of tissue surfaces and navigation through specific host compartments. (C) Group defensive strategies protect against environmental agonists. (D) Social interactions facilitate genetic exchange. (E) While the current review has primarily considered social behavior in the context of parasite-parasite signaling, cell-cell communication also occurs between the parasite and vector, host, and host microbiome, all of which will impact parasite transmission and pathogenesis. Studying these interactions is also expected to provide insight into the signal transduction pathways utilized by parasites.