• Numerous international scientific groups have reproduced the finding that bone marrow cells give rise to sperm generating cells
  • Bone marrow stem cells into the testes in small mammals treat a deficiency of germ cells (precursors of sperm cells), Sertoli cells (cells that aid in sperm development) and/or Leydig cells (testosterone-producing cells)
  • 3 international human studies underway

A segment of seminiferous tubule squashed from UBC-GFP transgenic mouse shows GFP-positive cells (A) and spermatozoa (B) visualized under fluorescent microscope. Note green cytoplasmic droplets on spermatozoa (arrows). Scale bars: 0.2 mm (A); 10 μm (B).