| Defense against microbes that become pathogenic and/or parasitic, and the need to maintain genetic integrity of self in the face of allogeneic contact are evolutionary pressures implicated in shaping the molecules that act to detect these assaults and the subsequent molecular complex that comprise animal immune systems. Cnidarians have been often used as research models to study the repertoire of developmental genes underlying the evolution of eumetazoan body plans. In a similar way, the composition of immune components in cnidarians can illuminate the evolutionary origins of animal immune systems. It is to this endeavor that my dissertation research contributes, using the hydrozoan Cnidaria model Hydractinia symbiolongicarpus. With this dissertation, I have addressed selective pressures that may have led to the evolution of self/nonself recognition molecules in Hydractinia and have identified and characterized immune related genes from which two broad conclusions can be drawn: the cnidarian immune gene repertoire shows apparent novel innovation in addition to containing the evolutionary origins of immune genes that have been well conserved across eumetazoan taxa, including humans. |
