New eggs from old mice?

The paper:

J. Johnson et al., "Oocyte generation in adult mammalian ovaries by putative germ cells in bone marrow and peripheral blood," Cell, 122:303-15, 2005. (Cited in 81 papers)

The finding:

Jonathan Tilly, director of the Vincent center for reproductive biology at Massachusetts General Hospital, and colleagues showed in 2005 that mice sterilized by chemotherapy or lacking a key gene for making oocytes could be prompted to develop immature oocytes after bone marrow transplantation.

The controversy:

Subsequent studies appeared suggesting that bone marrow stem cells couldn't possibly produce mature fertilizable eggs, and Tilly had to counter claims that he overinterpreted results.

The new finding:

Now, an in-press study in the Journal of Clinical Oncology reveals that in a mouse model of chemotherapy-induced ovarian failure, bone marrow transplant restored fertility. But, the offspring are not derived from donor stem cells.

The optimism:...