Expression analysis of up- and down-regulated genes in zSPs and zMPs. (A-C) Semiquantitative RT-PCR was performed in zSPs and zMPs. The expression levels of up-regulated genes (apoe, egr1, f11r, gata2, id1, krt18, meis1, and timp2) (A) and down-regulated genes (eif1ay, h2afz, pola1, and rfc4) (B) were compared between zSPs and zMPs. cd45 and ef1α were used as a blood cell marker and an internal control, respectively (C). NC indicates negative control. (D-E) A qPCR assay was performed in zSPs, zMPs, and zebrafish kidney. Expression of the ef1α gene was used to normalize the amount of the investigated transcripts. Relative expression levels in zSPs and zMPs were calculated from the expression levels in zebrafish kidney. Results are presented as an average expression level ± SD (n = 4). There are significant differences between zSPs and zMPs (*P < .001).