Tampa, FL (Nov. 10, 2006) -- We're not close kin to the sea urchin, but genetically speaking we may have more in common than we think.
The decoding of the sea urchin genome featured in the Nov. 10 issue of the journal Science is accompanied by a companion article written by scientists from the University of Toronto, George Washington University, and the University of South Florida College of Medicine, including affiliates All Children's Hospital and H. Lee Moffitt Cancer Center.
In "Genomic Insights into the Immune System of the Sea Urchin," the authors, including USF geneticist Gary Litman, PhD, contend that the comprehensive analysis of the sea urchin genome has broad implications for understanding primitive host defense and the genetic underpinnings of immunity in vertebrates. An international team of researchers sequenced the entire genome of the purple sea urchin (Strongylocentrotus purpuratus), which like humans belongs to the evolutionary lineage known as deuterostomes.
The sea urchin has emerged as one of the leading models for analyzing genetic regulatory networks that control development. Sea urchins belong to one side of the deuterostome evolutionary split and a few invertebrates (termed protochordates) as well as vertebrates, including humans, belong to the other side of the split.
The investigators detected in the sea urchin an extraordinarily large number of genes that encode molecules involved in natural or innate immunity, the first line of defense against microorganisms. Innate immunity is preformed and directly inherited.
Surprisingly, the international team also found elements of the more customized adaptive immune system, which in vertebrates produces a complex arsenal of antibodies and T-cell receptors to fend off diverse pathogens and prevent repeated attacks. Adaptive immunity, which is not necessarily inherited and arises uniquely in each individual, was not seen until the emergence of v
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Contact: Anne DeLotto Baier
abaier@health.usf.edu
813-974-3300
University of South Florida Health
9-Nov-2006