Lifesparing Ability (In Lethally Irradiated Mice) of W/W v Mouse Marrow with No Macroscopic Colonies

Marrow suspensions from W/Wv genetically anemic mice had 13% the 30-day lifesparing ability of +/+ marrow cells in lethally irradiated recipients, but formed less than 0.01% as many macroscopic spleen colonies. Although 75× 10⁶ W/Wᵛ cells produced no colonies after 9 or 10 days, they increased spleen weights significantly in irradiated recipients, but with less than 1% of +/+ cell efficiency. Nonerythroid cell proliferation (DNA synthesis) measured by125 IUdR uptake in recipients of W/Wv cells was 44% that in recipients of +/+ cells. Erythroid proliferation was insignificant in recipients of W/Wv cells, and substantial (150% of nonerythroid proliferation) in recipients of +/+ cells. Recipients of large doses of W/Wv cells survived as well as +/+ cell recipients for 190 days, but more died between 190 and 372 days. The macrocytic anemia of the W/Wv cell donors was permanently acquired in 2-3 months by 60-80% of W/Wv cell recipients, and recipients saved by W/Wv marrow cel...