Fibroblast growth factor signaling and spermatogonial stem cell self-renewal.

Spermatogonial stem cells (SSCs) serve as the foundational units for all adult male germ cells, playing a critical role in male fertility. These cells are characterized by their unique ability to balance self-renewal and differentiation, ensuring the maintenance of tissue homeostasis while simultaneously producing mature spermatozoa. Recent studies have highlighted the pivotal role of fibroblast growth factor (FGF) signaling in regulating SSC self-renewal, with various FGFs and their corresponding FGF receptors (FGFRs) being implicated in the intricate processes governing SSC homeostasis. This review aims to provide a comprehensive overview of the characteristic expression patterns of FGFs and FGFRs within germ cells and their surrounding somatic cells. In addition, we will conduct in-depth research on the multifaceted functions and regulatory mechanisms of FGF signaling in SSCs and elucidate its potential clinical significance. Understanding these mechanisms not only enhances our knowledge of male reproductive biology but also opens avenues for innovative clinical applications aimed at safeguarding fertility in vulnerable populations.