G-csf encourages myeloid differentiation as assayed by morphology and gene expression of isolated colonies. (A) Cytocentrifuged colonies isolated from precursor (top) and lymphoid (bottom) fraction methylcellulose cultures were stained with May-Grünwald-Giemsa. Tight colonies were isolated from cultures with only carp serum and Epo (left column), whereas ruffled and spread colonies were isolated from cultures containing carp serum and G-csf (right column). All images were photographed at magnification 1000×; scale bar in bottom right is 20 μm. After photographing, cells were cut and pasted from multiple fields to create a composite image. (B) Reverse transcription-PCR analysis of colonies isolated from precursor (top) and lymphoid (bottom) fraction of methylcellulose cultures. Colony morphology is listed on left, and genes assayed are listed along top of gel images.