In a study published online this week in Nature, an international team of researchers report the first complete sequence of the Atlantic cod genome and an unexpected discovery of the unique immune system of this important species.
Led by researchers from the University of Oslo, a consortium of Norwegian universities and aquaculture institutions turned to 454 Sequencing Systems from Roche (SIX: RO, ROG; OTCQX: RHHBY) to obtain a comprehensive de novo assembly of the highly complex cod genome at a fraction of the time and cost of traditional sequencing methods. Strikingly, the researchers found that Atlantic cod has lost genes that are essential for a critical component of its immune system. The findings call to question fundamental ideas on the evolution of the immune system in all vertebrate species.
"The overall aim of this initiative was to obtain the entire genome sequence of the Atlantic cod utilizing cutting edge sequencing technology," said study lead Professor Kjetill S. Jakobsen from the Centre for Ecological and Evolutionary Synthesis, University of Oslo. "We had not expected to find that the Atlantic cod had lost such a crucial component of its immune system." Despite lacking genes essential for the function of the major histocompatibility (MHC) II pathway, the Atlantic cod appears to function normally and relies on an increased number of MHC I genes and Toll-like receptor genes for its immune response. This finding will potentially allow for the development of more targeted vaccine development — aiding disease management and the process of domestication of Atlantic cod.
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