Identification and expression profiles of prdm1 in medaka Oryzias latipes.

Mouse Prdm1, also known as Blimp1, plays important roles in maturation and survival of lymphoid cells, as well as in organogenesis of muscle, limb, sensor organs and primordial germ cells. The homologues of mouse prdm1 have been identified in a diverse of animals including zebrafish and fugu. Here, we report the identification and expression profiles of two homologues of prdm1, namely prdm1a and prdm1b in medaka, Oryzias latipes. The transcripts of prdm1a and prdm1b were detectable in all the tissues including immune organs such as gill, spleen, kidney, liver and intestine that we have checked on. The transcripts of prdm1a could be detected in the embryonic shield at mid-gastrula stage and later in the somite, eye, otic vesicle, branchial arches, fin, intestine and cloaca during embryogenesis using in situ hybridization. Moreover, the expression of prdm1a in the liver of both medaka and zebrafish could be up-regulated by the immune stimuli including lipopolysaccharide, polyI:C and the grass carp reovirus, similarly to the up-regulation of IL1B. These results indicate that Prdm1a may play important roles in embryogenesis and also in immune response in fish.