May NUI Galway study finds a role for a chromosomal protein in stem cell division that has potential to improve fertility

Researchers from the Centre for Chromosome Biology at NUI Galway, who study the genetics of fruit flies as a way to understand human health, have investigated mechanisms of how stem cell divisions are regulated. Cell division has been found to have implications in areas such as fertility, ageing, cancer and regenerative medicine and this research has found that the function of a particular chromosomal protein, called CENP-C, is important to keep a pool of dividing stem cells in a tissue.

The study examined how stem cells divide in the ovary of the fruit fly, Drosophila melanogaster. The fruit fly serves as an ideal model for understanding how human stem cells divide, given that 60 per cent of its genes are also found in humans and they can also regenerate stem cells to repair and replace old or damaged cells.

Stem cells are unique in that they have the ability to regenerate themselves. They can also undergo cell division to give rise to a cell that can take on a new function. In the testes and ovaries, specialised stem cells, called germline stem cells, give rise to cells that differentiate to form the gametes, eggs and sperm. Defects in germline stem cell divisions can lead to infertility and sterility.

The study found that when the chromosomal protein CENP-C was removed from germline stem cells in the fly ovary, the production of eggs was interrupted and could lead to infertility. Specifically, the research found that over time the pool of germline stem cells was depleted in the ovary. These results suggest that CENP-C is important in the division of stem cells and can help scientists understand more on how stem cells work. The study also showed that the level of this chromosomal protein present in older stem cells is reduced compared to younger stem cells, and shows that it can also be used to mark stem cell age.

The gene that encodes the chromosomal protein CENP-C in the fruit fly also exists in humans and these findings suggest it is possible that it might function similarly in human stem cells. Restoring this gene in defective stem cells could potentially allow stem cells to function better or to improve fertility.

Dr Elaine Dunleavy, lead author of the study from the Centre for Chromosome Biology at NUI Galway, said: "Our work in fruit flies allows us to manipulate genes to understand their function in stem cells in the ovary that would not be possible to carry out in humans. Through this approach we hope to uncover genes that might be important for human fertility.”

The study has been published in the international journal PLoS Genetics and can be read in full at: https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1009247.

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