Press Release

September 29, 2011

Incorporated Administrative Agency, Fisheries Research Agency

Progress in the analysis of nori genome

  • Discovery of a gene involved in high-temperature water resistance
  • Found many useful markers for identifying varieties

Nori seaweed is sensitive to high water temperatures. In autumn 2007, nori harvesting was delayed for one month due to high seawater temperature. Superior new nori varieties that can adjust to such environmental changes need to be developed. Susabi-nori (Pyropia yezoensis), which is the main species for nori cultivation, is a northern species and is thus believed to be sensitive to high temperatures, but its physiological responses at high temperatures have been unknown

The Fisheries Research Agency has generated a draft genome sequence of P. yezoensis jointly with Hitachi Software Engineering Co., Ltd. and Japan Software Management Co., Ltd. This time, we discovered and isolated three genes encoding heat-shock proteins (HSPs) that are likely to be used as a protection measure when the seaweed is exposed to high temperatures. A number of microsatellite DNA marker candidates were also found on the genome, which will help discriminate nori varieties used in products, which are impossible to distinguish from their external appearance.

The information on the location of the HSP genes on the genome will accelerate studies on the gene functions, elucidation of the mechanisms involved in high-temperature resistance, and creation of new high-temperature-resistant varieties. DNA markers for discriminating nori varieties in products will be constructed to help protect the breeding rights of nori varieties in Japan.

The results will be published at the autumn meeting of the Japanese Society of Fisheries Science. Because the genomic information of P. yezoensis was found to be very useful for analyzing the functions of genes, etc., further gene analyses are being conducted, and the results will be published at a meeting of the Japanese Association of DNA Testing

*The results were obtained as part of the study projects “Entrusted study project for developing sustainable technologies for fishery environment and fisheries resources” and “Entrusted study project for developing technologies for assessing the impacts of global warming on coastal fishery environment and adaptive technologies,” commissioned by the Fisheries Agency.