Ix73microscope

Worms were paralysed in 10 mM levamisole and imaged as described
previously^{37 (link)}. To
assess the intensity of GFP fluorescence, 6–7 worms of the same group
were placed onto a single slide and imaged using an Olympus IX73 epifluorescence
microscope with LAS software (Leica). The GFP images shown within each figure
panel were collected using the same acquisition setting. GFP fluorescence was
quantified using ImageJ software (National Institutes of Health). To examine the
spatial expression and subcellular localization, GFP and differential
interference contrast (DIC) images were obtained using Zeiss LSM710 confocal
microscope and processed using ZEN software (Zeiss). To monitor the worm growth
and lethality, brightfield images were collected using the Olympus IX73
microscope with LAS software (Leica).

Zebrafish larvae were fixed with 4% paraformaldehyde and dehydrated with
increasing concentrations of ethanol. After embedding in paraffin, tissues were
sectioned to 3-μm thickness and were stained with haematoxylin and eosin.
Images were acquired on an Olympus IX73 microscope with LAS software
(Leica).

Haemoglobin in MEL cells and zebrafish embryos was stained with
o-dianisidine following the described method^{35 (link)}. MEL cells were stained with
o-dianisidine (0.68 mM o-dianisidine, 14
mM acetic acid, 73 mM H₂O₂) at day 3 after DMSO-induced
differentiation. Zebrafish embryos were stained with
o-dianisidine (2.54 mM o-dianisidine, 11 mM
sodium acetate, 0.22 M H₂O₂) at 48 and 72 h
post-fertilization (hpf). The stained samples were analysed with an Olympus IX73
microscope or Leica M165 FC microscope connected to a Leica DFC310 FX camera.
Images were acquired and processed using LAS software (Leica).