%0 Journal Article
%T Evolution of innate immunity
%A Cathy Holding
%J Genome Biology
%D 2004
%I BioMed Central
%R 10.1186/gb-spotlight-20040709-01
%X 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 us. "It's no wonder that for so many years it was a big mystery," he added, "because everyone until now more or less linked adaptive immunity with rearranging immunoglobulin genes, as it is from sharks up to man."Experts are uncertain whether the findings illustrate convergent evolution. Pancer believes that at the lamprey level, this is not yet convergent evolution but merely a continuation of the usage of a very ancient motif - the leucine rich repeat - that is conserved in man, invertebrates, and plants.Max D. Cooper, coauthor of the paper, also believes in the common ancestor idea. "I think the strategy of using the kind of building blocks like toll and toll-like receptors and other innate immune receptors was used by many different organisms, but with a single gene," Cooper told us.Cooper fully anticipates that the mechanism will be present in hagfish as well, and the authors had 'hints' that it will still be present going forward into the jawed vertebrates, although he did not know how far. "I would imagine that since every living thing on the planet uses this kind of building block, these leucine rich repeat sequences, for defense, that having the ability to vary them within an indiv
%U http://genomebiology.com/2004/5/7/spotlight-20040709-01