Backboner

A couple of years ago, I went to the meeting of the Society for the Study of Reproduction (SSR) where J. Tilly presented his paper on the repopulation of germ cells in the ovary by a circulating stem cell in the blood. It was the first time that I saw both a standing ovation and grumbling from skeptics at a scientific talk. It went against everything we knew about female germ cells, and raised the possibility that woman with bone marrow tranplants or blood transfusion may not be the biological mothers of their own child. I am still not 100% convinced, but the idea that the niche can dictate what a stem cell will become is becoming more and more supported by evidence. This recent report that bone marrow cells injected in the testes can give rise to sperm further substantiates that claim. So maybe females can become, biological fathers? And it is good news for my friend who's spontaneously grown ovaries after watching too much dancing with the stars...