Expansion of marrow cells and emergence of the hematon during perinatal ages.

The femoral inner mass was recovered from 8 to 12 embryos or little mice. Half of each tissue was used to prepare a single-cell suspension for quantitative colony assays and the other half to count hematons and native cobblestone colonies at day 7 in LTC. The numbers of TNC (○), total GM-CFC and HPP-CFC (●), and day 7 CAFC (⋄) increased logarithmically from E17. Day 35 LTC-IC/CAFCs (♦) appear at day 2, and hematon units containing native CA (■) emerge from days 5 to 7.