Eight Proteins Turn Mouse Stem Cells into Egglike Cells

The identification of the transcription factors that elicit oocyte growth will aid reproductive biology research and might help women with fertility issues, scientists say.

A core set of eight proteins can transform stem cells from mice into cells that look a lot like immature egg cells called oocytes. The egglike cells could not undergo meiosis to cut the total chromosomes in half as they should, but they could be fertilized by sperm and then divide until they hit the eight-cell stage of embryonic development.

“This demonstrates that you can go directly from stem cells to oocytes. I think that is exciting,” Petra Hajkova, a developmental epigeneticist at Imperial College London who was not involved in the study, tells The Scientist. The work, she notes, will help researchers explore the basic biology of oocyte development.

In the future, says study coauthor Nobuhiko Hamazaki of Kyushu University, the research could aid in cloning endangered animals or helping women with mitochondrial diseases to have healthy children.

Oocytes are a rare cell type in the body and not much is known about them, Hamazaki says, which is what led him and his colleagues to probe how they develop. The experiments revealed eight transcription factors that were essential to oocyte development: NOBOX, FIGLA, TBPL2, SOHLH1, STAT3, DYNLL1, SUB1, and LHX8.