CYTOKINE GENES OF JAPANESE FLOUNDER

¹ Laboratory of Genome Science, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477, Japan

The fish immune system comprises of the non-specific and specific immune defences,�@having both humoral and cellular mechanisms�@to resist against infectious diseases. Prominent among these molecules are cytokines. Cytokines are a diverse group of soluble proteins and peptides which act as humoral regulators at small concentrations and which, either under normal or pathological conditions, modulate the functional activities of individual cells and tissues. However, the cytokine network system of fish are poorly understood at the molecular level. We have cloned full length cDNAs for Interleukin 1, Interleukin 8, tumor necrosis factor (TNF), Fas ligand, G-CSF, TGF-beta, four different types of CC chemokines, CXC chemokine, IL1 receptor type II, IL6 receptor, IL8 receptor, TNF receptor type 1 and type 2, G-CSF receptor and chemokine receptors. Identities between Japanese flounder cytokines and those of mammal or chicken ranged from 30 � 60 %. Currently the expression pattern for these genes, from LPS or ConA/PMA treated peripheral blood leukocytes are characterized by cDNA microarray and quantitative real-time fluorescence RT-PCR. The expression patterns and the amount of expressed mRNAs of these genes were different in the various genes examined, stimulations and time points. From our analysis we concluded that the cDNA microarray and real-time fluorescence RT-PCR should be the standard method for any experiments requiring sensitive and specific quantification of mRNAs.