Glycylglycine plays critical roles in the�proliferation of spermatogonial stem cells

Glial cell line‑derived neurotrophic factor (GDNF) is critical for the proliferation of spermatogonial stem cells (SSCs), but the underlying mechanisms remain poorly understood. In this study, an unbiased metabolomic analysis was performed to examine the metabolic modifications in SSCs following GDNF deprivation, and 11 metabolites were observed to decrease while three increased. Of the 11 decreased metabolites identified, glycylglycine was...