Ploidy distribution of CFU-Meg progeny.

In their study of the DNA levels (ploidy) of murine megakaryocyte colonies, Chatelain and Burstein evaluated the effects of acute thrombocytopenia upon the ploidy of megakaryocyte colonies derived from mice that had received platelet antiserum.’ They reported that colonies derived from bone marrow, obtained 24 hours after the administration of platelet antiserum, demonstrated the same ploidy distribution as did control colonies, in agreement with our observations when marrow or spleen was cultured 48 hours after the administration of platelet antiserum.2 However, the authors’ sweeping conclusion that “An acute thrombocytopenic environment does not influence the ultimate ploidy of the progeny of CFU-M” is not justified. While they are correct in stating that a similar result was described by us two days following thrombocytopenia,2 they also should have indicated that when colonies were derived from bone marrow or spleen four orfive days