In the meantime, Van Gilst and colleagues will continue to study the tiny worm to better understand the basic mechanisms that control fertility. One question their research may help address is how in some cases women recovering from radiation and bone marrow transplantation - which damages or destroys much of the germline, including mature and immature eggs - can regain their fertility.

"There is controversy over how this occurs," Van Gilst said. "On the one hand, it has been argued that new eggs are generated from the woman's germline stem cells through a process that may mirror the germline regeneration we observed in C. elegans. In fact, there is controversy over whether or not germline stem cells exist in adult women. We believe that our work in C. elegans throws another hat in the ring, raising the possibility that germline stem cells may indeed be present in women and that their activity may surface under conditions of nutrient deprivation or stress," he said.

This work may also shed new light on cancer. "Cancer cells, when starved, are very susceptible to cell death. However, cancer stem cells, or progenitor cells, often thrive and flourish during starvation in cell-culture experiments. When nutrition is restored, these cells can trigger rapid regrowth. Consequently, understanding how germline stem cells in C. elegans survive starvation may help appreciate how cancers survive treatments aimed at starving tumors," he said.

For the study, the researchers withheld food from two types of nematodes: those that were genetically normal and those that lacked a functioning NHR-49 gene. The worms were monitored every few days by microscopy to observe changes in their reproductive system, including ovulation, cell death and germline stem cell survival. After different periods of starvation, food was restored and the worms were again monitored by microscopy to assess the recovery of their reproductive system. Fertility was determined by counting offspring after mating.

Source: Fred Hutchinson Cancer Research Center