Evolution of innate immunity

A new type of highly variable lymphocyte receptor discovered in the lamprey suggests two distinct evolutionary strategies to generate receptor diversity in vertebrates, according to a Nature paper this week.

The discovery, by Zeev Pancer and Max D. Cooper at the University of Alabama at Birmingham, shows that evolutionarily diverse vertebrates have a similar fundamental strategy of somatic rearrangement of germline receptor units to combat infectious disease.

The fundamentals are similar across species, but in jawed vertebrates, diversity is generated by joining gene segments in the immunoglobulin and T-cell receptor gene loci, while in the sea lamprey Petromyzon marinus (a jawless vertebrate), the Alabama team found a completely different set of molecules that mediate adaptive immunity—with a completely different molecular structure and molecular architecture.

"After more than 40 years of evidence of adaptive immunity in agnathans [jawless fish], we found the molecules," Pancer told The Scientist. "It's no wonder that ...