Project description:Human adult spermatogenesis involves a balance of spermatogonial stem cell self renewal and differentiation, alongside complex germline-niche interactions. To better understand, we performed single cell RNA sequencing of ~7000 testis cells from three healthy men of peak reproductive age. Our analyses revealed multiple distinctive transcriptional ‘states’ of self-renewing and differentiating spermatogonia, the cellular stages of gametogenesis, five niche cells (Leydig, Myoid, Sertoli, Endothelial, macrophage) and insights into germline-niche communication. Spermatogenesis was reconstructed computationally, which identified sequential coding, noncoding, and repeat-element transcriptional signatures. A new, developmentally early and likely quiescent spermatogonial state is identified (GFRA1-/ETV5-/ID4+/UTF1+/FGFR3+). Notably, certain epigenetic features combined with nascent transcription analyses suggest considerable plasticity within certain spermatogonial populations/states. Key findings were validated via RNA and protein staining. Taken together, we provided the first “Cell Atlas” of the adult human testis, and provide multiple new insights into germ cell development and germ cell – niche interaction.
Project description:Human testis development in prenatal life involves complex changes in germline and somatic cell identity. To better understand, we profiled and analyzed ~32,500 single-cell transcriptomes of testicular cells from embryonic, fetal and infant stages. Our data shows that at 6-7 weeks post-fertilization as the testicular cords are established, the Sertoli and interstitial cells originate from a common heterogeneous progenitor pool, which then resolves into fetal Sertoli cells (expressing tube-forming genes) or interstitial cells (including Leydig-lineage cells expressing steroidogenesis genes). Almost ten weeks later, beginning at 15-16 weeks post-fertilization, the male primordial germ cells exit mitosis, downregulate pluripotent transcription factors and transition into cells that strongly resemble the ‘State 0’ spermatogonia originally defined in the infant and adult testes. Therefore, we termed these fetal spermatogonia ‘State f0’. Taken together, we reveal multiple insights into the coordinated and temporal development of the embryonic, fetal and postnatal male germline together with the somatic niche.
Project description:Human adult spermatogenesis involves a balance of spermatogonial stem cell self renewal and differentiation, alongside complex germline-niche interactions. To better understand, we performed single cell RNA sequencing of ~7000 testis cells from three healthy men of peak reproductive age. Our analyses revealed multiple distinctive transcriptional ‘states’ of self-renewing and differentiating spermatogonia, the cellular stages of gametogenesis, five niche cells (Leydig, Myoid, Sertoli, Endothelial, macrophage) and insights into germline-niche communication. Spermatogenesis was reconstructed computationally, which identified sequential coding, noncoding, and repeat-element transcriptional signatures. A new, developmentally early and likely quiescent spermatogonial state is identified (GFRA1-/ETV5-/ID4+/UTF1+/FGFR3+). Notably, certain epigenetic features combined with nascent transcription analyses suggest considerable plasticity within certain spermatogonial populations/states. Key findings were validated via RNA and protein staining. Taken together, we provided the first “Cell Atlas” of the adult human testis, and provide multiple new insights into germ cell development and germ cell – niche interaction.
Project description:Human adult spermatogenesis involves a balance of spermatogonial stem cell self renewal and differentiation, alongside complex germline-niche interactions. To better understand, we performed single cell RNA sequencing of ~7000 testis cells from three healthy men of peak reproductive age. Our analyses revealed multiple distinctive transcriptional ‘states’ of self-renewing and differentiating spermatogonia, the cellular stages of gametogenesis, five niche cells (Leydig, Myoid, Sertoli, Endothelial, macrophage) and insights into germline-niche communication. Spermatogenesis was reconstructed computationally, which identified sequential coding, noncoding, and repeat-element transcriptional signatures. A new, developmentally early and likely quiescent spermatogonial state is identified (GFRA1-/ETV5-/ID4+/UTF1+/FGFR3+). Notably, certain epigenetic features combined with nascent transcription analyses suggest considerable plasticity within certain spermatogonial populations/states. Key findings were validated via RNA and protein staining. Taken together, we provided the first “Cell Atlas” of the adult human testis, and provide multiple new insights into germ cell development and germ cell – niche interaction.
Project description:The human testis undergoes dramatic developmental and structural changes during puberty, including proliferation and maturation of niche/somatic cells, and the onset of spermatogenesis. Here, we profiled and analyzed single-cell transcriptomes of ~10,000 testicular cells from four boys spanning puberty, and compared to infants and adults. During puberty, undifferentiated spermatogonia first expand and then differentiate, prior to gametogenesis. Notably, we identify a common pre-pubertal progenitor for Leydig and myoid cells, and reveal candidate factors/pathways for pubertal differentiation. Furthermore, pre-pubertal Sertoli cells form two states that differ in mitochondrial/metabolic transcription, which converge to a single mature population during puberty. Roles for testosterone in Sertoli cell maturation, antimicrobial peptide secretion and spermatogonial differentiation are revealed through analyses of testosterone-suppressed transgender female testis and via in vitro seminiferous tubule culturing. Overall, our transcriptional atlas of the developing human testis provides major insights into developmental changes and key factors/pathways that accompany male puberty.