Supplemental materials and methods
Zebrafish husbandry
Wild-type AB and pu.1G242D mutant zebrafish were maintained as described
previously. 1, 2
Whole-mount in situ hybridization (WISH)
Antisense digoxigenin (DIG)-labeled RNA probes and WISH were performed
according to standard protocols.2 Images were captured using a Nikon AZ100
microscope. For WISH, probes of cebpa,3 cebp1,4 mpx,5 lyz,6 mfap4,7 ande1-globin8
were prepared as reported.
Sudan Black Staining
Fixed embryos incubated in Sudan black (SB; Sigma-Aldrich) solution as described.9
The SB-stained embryos washed by 70% ethanol, and signal were detected under
microscope.
Tyramide-based detection of endogenous peroxidase activity
Tyramide-based detection of endogenous peroxidase activity performed essentially as
described previously.9
Cytological analysis
Hematopoietic cell were isolated as described previously.10 Zebrafish were euthanized
with tricaine. PB of fish was obtained by gill puncture with a 10-μl heparinized glass
microhematocrit tube. Blood cells were isolated from the kidney marrow (KM). Both
PB and KM were re-suspended in ice-cold PBS with 5% FBS, followed by cytospins
at 400 rpm for 3 minutes and subjected to May-Grunwald Giemsa (Merck) staining
according to the manufacturer's instructions. Blood cells of KM and PB in WT and
pu.1G242D fish were calculated manually based on their morphology.10
For 2-month-old fish, 2 groups were analyzed. Every group of PB and KM from
wild-type or pu.1G242D was collected from 4 fishes. For older than 2-month-old fish,
more than 9 groups were analyzed. Each group of PB and KM was collected from 1
fish.
Chemotherapy treatment of pu.1G242D embryos
Embryos (1 dpf) were soaped in egg water containing 103 mg/L cytarabine or 30 mg/L
daunorubicin for 4 days. The treated larvae (5 dpf) were collected for Sudan Back B
(SB) staining.
BrdU and TUNEL labeling
Bromodeoxyuridine (BrdU) labeling was performed as described11 with minor
modifications12. pu.1G242D/Tg(lyc:dsred) intercross embryos at 72 hpf were incubated
in 10 mM BrdU (Sigma-Aldrich) for 2 h, fixed in 4% paraformaldehyde, stained with
mouse-anti-BrdU (Roche) and goat-anti-dsred Abs (Abcam), followed by Alexa Fluor
488 anti–mouse (Abcam) and Alexa 555 anti-goat (Abcam) for fluorescent
visualization. TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling)
assay was carried out as described,13 followed by goat-anti-dsred Abs (Abcam) and
Alexa 555 anti-goat (Abcam). Images were captured using a Zeiss LSM 510 confocal
microscope.
Statistical analysis
Fisher exact tests were used to determine the differences between categorical
variables. T-tests were applied to compare continuous variables. ALL Statistical data
were tested for significance by 2-tailed analysis.
Supplemental references
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the zebrafish, Dev Dyn 1995, 203:253-310
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Westerfield M: The zebrafish book. A guide for the laboratory use of zebrafish (Danio rerio).
Edited by Eugene, Univ. of Oregon Press, 2000,
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Lyons SE, Shue BC, Lei L, Oates AC, Zon LI, Liu PP: Molecular cloning, genetic mapping, and
expression analysis of four zebrafish c/ebp genes, Gene 2001, 281:43-51
4.
Lyons SE, Shue BC, Oates AC, Zon LI, Liu PP: A novel myeloid-restricted zebrafish
CCAAT/enhancer-binding protein with a potent transcriptional activation domain, Blood 2001,
97:2611-2617
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Lieschke GJ, Oates AC, Crowhurst MO, Ward AC, Layton JE: Morphologic and functional
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gene functions in Spi1-directed innate immunity, Blood 2010, 116:e1-11
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pattern of transcription during embryogenesis, Development genes and evolution 1999, 209:126-131
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Le Guyader D, Redd MJ, Colucci-Guyon E, Murayama E, Kissa K, Briolat V, Mordelet E, Zapata A,
Shinomiya H, Herbomel P: Origins and unconventional behavior of neutrophils in developing zebrafish,
Blood 2008, 111:132-141
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multilineage engraftment in zebrafish bloodless mutants, Nature immunology 2003, 4:1238-1246
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zebrafish, Mechanisms of development 2005, 122:157-173
12. Zhang Y, Jin H, Li L, Qin FX, Wen Z: cMyb regulates hematopoietic stem/progenitor cell
mobilization during zebrafish hematopoiesis, Blood 2011, 118:4093-4101
13. Du L, Xu J, Li X, Ma N, Liu Y, Peng J, Osato M, Zhang W, Wen Z: Rumba and Haus3 are essential
factors for the maintenance of hematopoietic stem/progenitor cells during zebrafish hematopoiesis,
Development 2011, 138:619-629
Supplemental Figure Legends
Figure S1 Expansion of immature myeloid cells in larvae, juvenile and adult pu.1G242D
fish. (A) WISH ofβe1-globin expression in 5 dpf (Fisher exact tests, n≥17, P=0.497,
no statistical significance). (B-I) blood cell counts of KM and PB. KM blood cells (B,
F) and peripheral blood (PB) cells (D, H) in 2 month-old (B, D) and 12 month-old (F,
H) WT and pu.1G242D fish stained with May-Grunwald/Giemsa staining. Arrowheads,
arrows, and asterisks indicate progenitors, myeloid cells, and lymphocytes
respectively. Original magnification is 100x. Blood cell counts of KM (C, G) and PB
(E, I) in 2 month-old (C, E) and 1 year (G, I) WT (blue bars) and pu.1G242D (red bars)
fish were calculated manually based on their morphology (t-test, n≥7, mean±SD,
*P≤0.05, **P≤0.01).