Hemopoietic stem cells bear sperm-associated antigens.

A fluorescence-activated cell sorter has been used to sort out enriched populations of murine hemopoietic stem cells from mouse bone marrow, based on fluorescence of cells labeled with various antisera. Significant positive enrichment for stem cells was obtained with rabbit anti-human brain, human anti-human sperm and mouse anti-mouse F9 sera but not with mouse anti-mouse Ia serum. These results support the hypothesis that the hemopoietic stem cell exhibits 'unique' surface antigens cross-reactive with sperm, brain and embryonic antigens.