Accelerated differentiation of RARα−/− granulocytes in GM-CSF–dependent clonogenic cultures.
We plated 5 × 104 BM cells in methylcellulose medium containing 50 ng/mL GM-CSF. (A-D) Pooled cells from all the colonies developing on a dish (about 70 colonies) were cytocentrifuged onto a glass slide and stained with May-Grünwald-Giemsa. Arrowheads in panel A indicate promyelocytes that are numerous on slides from day-5 WT cultures, but are less frequent in mutant samples. The inset in panels A and B corresponds to the scoring of approximately 400 cells of the granulocyte lineage for each case. (E,F) Typical colonies from culture dishes at day 8; note the reduction in the number and size of dense cellular aggregates (arrows), which correspond to granulocytes.
