In contrast, caauCD2f-3 mRNA was predominantly expressed by the adherent cells. Also, although caauCD2f-2 mRNA expression in three fish was low or undetectable, it seems that caauCD2f-2 was expressed by both populations. SAP was only expressed by the non-adherent cells, suggesting the co-expression of SAP and caauCD2f-1/caauCD2f-4 in a similar cell population. Collectively,

caauCD2f-1, ATR inhibitor caauCD2f-4, and SAP are dominantly expressed in lymphocytes, and caauCD2f-2 and caauCD2f-3 is expressed by lymphocyte as well as monocytes/macrophages. RT-PCR analysis using templates from the purified lymphocyte subsets showed that the caauCD2fs were expressed by various lymphocyte subsets (Fig. 6). http://www.selleckchem.com/products/INCB18424.html caauCD2f-1, caauCD2f-2, and caauCD2f-3 were expressed by CD8α- and Ig-positive cells, suggesting that they are produced in cytotoxic T-cells (CTLs) and B-cells, but not helper T-cells (Th cells). Meanwhile, caauCD2f-4 was expressed by Th cells in addition to CTLs and other lymphocytes. caauCD2f-3 mRNA was detected in CD8- and CD4-negative lymphocytes,

suggesting that it is expressed on B cells, monocytes/macrophages and NK cells. In situ hybridization analysis showed that a part of the round nuclear cells (probably lymphocytes) and the irregular cells with large cytoplasm (probably monocytes or neutrophils) were caauCD2f-positive ( Fig. 7). Hybridizations using a probe capable of detecting all the caauCD2f isoforms showed that caauCD2f-positive cells comprised approximately 17% PBL, and an isoform-specific probe for caauCD2f-1 detected approximately 8.0% of the positive cells. This result indicates that caauCD2f-1-positive cells are a part of the caauCD2f population. To investigate the genomic organization of the teleost CD2f, we surveyed the zebrafish genome

database using BLAST searches with the extracellular domain of caauCD2f-1 as a query. As shown in Fig. 8, six sequences from the Ig domain were found on chromosome 1 (Zv9_scafold Immune system 51) and 29 of the sequences on chromosome 2 (Zv9_scafold 229 and 231), forming clusters within 0.6 Mbp in each chromosome. Searches performed using the sequences of caauCD2f-2, caauCD2f-3, and caauCD2f-3 yielded similar results (data not shown). The zebrafish sequences (zfCD2f-1.2) had 39–94% sequence similarity and 39–86% identity with the caauCD2f-1 sequence. Two putative Ig-like domains in most gene sets were separated with an intron. Synteny conservation was not found between the mammalian CD2 f and zfCD2f-1.2. According to the sequence similarity of their Ig-domain sequences, the zfCD2f-1.2 genes were classified into eight subgroups (I-VIII). As shown by their alignment (Fig. 9), the sequences showed high identity (78.4–97.8%) within each group, and several pairs (group II and VII) located on both chromosomes 1 and 2 shared substantially high (74.3–78.2%) identity (Fig. 9).