Identification of Spermatogonial Stem Cells and Genetic Control of All Stages of Spermatogenesis
An ability to identify SSCs by their transcriptome analysis would greatly benefit future treatment of male infertility. If you could determine the RNA expression of every stage of spermatogenesis, that would be a more reliable identification of cell type by gene expression than just histology. It would mean the elucidation of the total genetics of spermatogenesis. The identification of spermatogonial stem cells (SSCs) in particular in the human would help us better understand the origin of testicular cancers such as teratoma, choriocarcinoma, embryonal carcinoma, and seminoma, which arise in the testis from germ cells [1–5]. It is known that primordial germ cells (PGCs) arise from the fetal epiblast at the time of gastrulation and migrate eventually to the gonadal ridge to become spermatogonial stem cells (SSCs) in the male gonad. Any pluripotent stem cells that have not fully differentiated into PGCs when they enter the fetal testis could become a testis cancer. In fact cancers of the adult testis are composed of differentiated cells which represent all basic somatic cell types, much like what ES cells develop into if not suppressed in culture or in a niche. So the origin of testis cancer is most likely embryonic stem cells rests that entered the testis before fully converting to PGCs.
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