Abstract: The present invention provides a lipoxygenase that enables the highly efficient formation of an oxide of a highly unsaturated fatty acid or an oxide of a highly unsaturated fatty acid derivative from a highly unsaturated fatty acid or a highly unsaturated fatty acid derivative. The present invention provides a lipoxygenase that enables the highly efficient formation of 8-hydroxyeicosatetraenoic acid from arachidonic acid, the highly efficient formation of 8-hydroxyeicosapentaenoic acid from eicosapentaenoic acid, and the highly efficient formation of 10-hydroxy docosahexaenoic acid from docosahexaenoic acid. Specifically, the present invention provides a polynucleotide that comprises the nucleic acid sequence represented by SEQ ID NO: 1 and 3, or a homolog thereof, and a polypeptide that comprises the amino acid sequence represented by SEQ ID NO: 2 and 4, or a homolog thereof.

Abstract: This invention provides a method of gene expression analysis that enables extensive gene expression analysis and simultaneous analysis of multiple samples of organisms for which genomic analysis has not yet been advanced. In this method, tags each comprising an oligonucleotide of more than 25 bp for identifying expressed genes, wherein the 3?-end of the tag is defined by a cleavage site of a type III restriction enzyme and the 5?-end thereof is defined by a cleavage site of another restriction enzyme located closest to the 3?-end of the cDNA of such genes, are immobilized on a solid support, gene-containing samples are hybridized to the solid support, and the signals emitted from the genes hybridized to the tags are detected to analyze the gene expression profiles in the samples.

Abstract: The type III restriction enzyme EcoP15I is used to isolate from cDNA of an expressed gene a tag comprising more than 25 nucleotides and capable of identifying the expressed gene, wherein the 3? end of the tag is defined by a cleavage site of the type III restriction enzyme and the 5? end of the tag is defined by the cleavage site of another restriction enzyme that is closest to the 3? end of the cDNA of the expressed gene. The tag of the invention allows accurate quantitative gene expression analysis and rapid gene expression profiling in any organism for which no expressed sequence tag (EST) database is available.