This scholarly journal article examines aspects of how alliances with prokaryotes may have been integrated into the mechanisms and patterns of host animal developmental programs. Major concepts discussed include: the nature of cooperative associations (community structure, maintenance of community integrity over time-transmission of microbes between host generations, location of the cells of the partners and its relationship to mechanisms of reciprocal signaling), the existing database (germfree and gnotobiotic animals, bacterial pathogens, plant/nitrogen-fixing bacteria symbioses), and the Euprymna/Vibrio cooperative association.
