Single-Cell RNA-seq Transcriptome Profiling from Male Germ Cells Isolated from Late Fetal and Neonatal Mouse Testes

To better understand the underlying dynamics driving formation of the spermatogonial stem cell (SSC) pool during development, we performed single-cell RNA-sequencing on mouse germ cells isolated from testes during late fetal and early postnatal development. Transcriptome profiling revealed that a subset of prospermatogonia during late fetal development becomes preprogrammed to adopt the SSC fate in postnatal life. Further computational analysis mapped the transcriptional dynamics of the SSC trajectory through developmental time to identify novel pathways and regulators involved in formation of the foundational SSC pool. Paired with in vivo gene expression analysis via a multi-transgenic mouse model and functional assessment of germ cell fate via transplantation, the findings of our study present a model for which stem cell fate is preprogrammed in the spermatogenic lineage. Overall design: Testicular germ cells from a total of eight different mice across four developmental ages (E16.5, P0, P3, and P6) were used in this study.