The localization of Toll and Imd pathway and complement system components and their response to Vibrio infection in the nemertean Lineus ruber.

Background: Innate immunity is the first line of defense against pathogens. In animals, the Toll pathway, the Imd pathway, the complement system, and lectins are well-known mechanisms involved in innate immunity. Although these pathways and systems are well understood in vertebrates and arthropods, they are understudied in other invertebrates.

The evolution of the metazoan Toll receptor family and its expression during protostome development.

Background: Toll-like receptors (TLRs) play a crucial role in immunity and development. They contain leucine-rich repeat domains, one transmembrane domain, and one Toll/IL-1 receptor domain. TLRs have been classified into V-type/scc and P-type/mcc TLRs, based on differences in the leucine-rich repeat domain region.

Molecular and morphological analysis of the developing nemertean brain indicates convergent evolution of complex brains in Spiralia.

Background: The brain anatomy in the clade Spiralia can vary from simple, commissural brains (e.g., gastrotrichs, rotifers) to rather complex, partitioned structures (e.