Identification of up- and down-regulated genes in zSPs. Hematopoietic cells from zebrafish kidney were stained with Hoechst 33342 (Hoechst) and analyzed by FCM. (A) Scatter profile of kidney hematopoietic cells. Gated region indicates lymphoid cells (forward scatter [FS]low; side scatter [SS]low). (B) Hoechst fluorescence of the lymphoid cells. The lymphoid cells were subdivided into 2 populations, zSPs and zMPs. (C) The numbers of up- and down-regulated genes of zSPs. A total of 10 971 genes is present on the GeneChip Zebrafish Genome Array. Among them, 1077, 8981, and 913 genes were up-regulated, unchanged, and down-regulated in zSPs, respectively.