Fig. 2

 Transiently overexpressed IL-34 in liver led to macrophage enrichment in liver. A total of 1.8 nL (30 ng/μL) of the pBLK-fabp10a-il34-sv40 construct was microinjected into one-cell stage Tg (mpeg1: GFP) (A)and Tg (lyz: EGFP) (B) zebrafish embryos. (A, B) WISH of il34 expression and whole-mount antibody staining of GFP expression in 4 dpf embryo (6 × ). The whole body picture of the fish is made up of two separate images taken by confocal and stitched together in the Photoshop. Insets are high magnification (20 × ) of the corresponding boxed regions (gray dotted areas). (C, D) Quantitative analysis of macrophage or neutrophil cell numbers in uninjected and construct-injected embryos' liver (shown in white dotted area) and CHT tail region (approximately between the 13th and 17th somite, shown between two white dotted lines). Data were analyzed by Mann–Whitney U test, **p < 0.01 compared to control. n = 5, 5 for the 4 dpf injected and control fish. Bars: 200 μm (the line on 6 times objective pictures); 50 μm (the line on 20 times objective pictures). fabp10a, fatty acid binding protein 10a.