The bacterial relay race takes advantage of an ability to control cellular motility using inducible promoters such as those involved in nutrient catabolism or quorum sensing. “Receiver” bacteria move in response to small-molecule signals either added to the system or originating from motile, “sender” strains. The most significant challenges relating to this project stem from difficulties of tightly controlling the target motility gene motB. Low levels of motB expression result in system failure (constitutive motility), and resolving this issue is essential to developing reliable modular systems that are the hallmark of synthetic biology. If you are interested in joining the team click here.