Competition for Mitogens Regulates Spermatogenic Stem Cell Homeostasis in an Open Niche.
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Competition for a limited pool of growth factors determines the fate of stem cells in the testes, a mouse study has found.
A team, which included five scientists from the University of Tsukuba, studied the dynamics of mouse stem cells found in the seminiferous tubules of the male reproductive system.
They discovered that when fibroblast growth factors are limited, the cells tend to go down the path towards differentiated sperm, whereas abundant levels of the signalling protein tend to keep the cells in a state of self-renewal.
The researchers also found that the dosage of growth factor is tightly linked to cell density in the tissue microenvironment of the testes.
Backed by mathematical modelling, the team proposed that competition for resources can explain the regulation of the pool size of stem cells. It remains to be seen whether this holds outside of mouse gonadal tissue.
- Cell Stem Cell 24, 79–92 (2019). doi: 10.1016/j.stem.2018.11.013