Project description:Spermatogenesis is an intricate developmental process occurring in testes by which spermatogonial stem cells (SSCs) self-renew and differentiate into mature sperm. The molecular mechanisms for SSC self-renewal and differentiation, while have been well studied in mice, may differ between mice and domestic animals including pigs. To gain knowledge about the molecular mechanisms for porcine SSC self-renewal and differentiation that have to date been poorly understood, here we isolated and enriched primitive spermatogonia from neonatal porcine testes, and exposed the cells to retinoic acid, a direct inducer for spermatogonial differentiation. We then identified that retinoic acid could induce porcine primitive spermatogonial differentiation into leptotene spermatocyte-like cells, which was accompanied by a clear transcriptomic alteration, as revealed by the RNA-sequencing analysis. We also compared retinoic acid-induced in vitro porcine spermatogonial differentiation with the in vivo process, and compared retinoic acid-induced in vitro spermatogonial differentiation between pigs and mice. Furthermore, we analyzed retinoic acid-induced differentially expressed long non-coding RNAs (lncRNAs), and demonstrated that a pig-specific lncRNA, lncRNA-106504875, positively regulated porcine spermatogonial proliferation by targeting the core transcription factor ZBTB16. Taken together, these results would help to elucidate the roles of retinoic acid in porcine spermatogonial differentiation, thereby contributing to further knowledge about the molecular mechanisms underlying porcine SSC development and, in the long run, to optimization of both long-term culture and induced differentiation systems for porcine SSCs.
Project description:A bioenergetic balance between glycolysis and mitochondrial respiration is particularly important for stem cell fate specification. It however remains to be determined whether undifferentiated spermatogonia switch their preference of bioenergy production during differentiation. In this study, we found that ATP generation in spermatogonia was gradually increased upon retinoic acid-induced differentiation. To accommodate this elevated energy demand, retinoic acid signaling concomitantly switched ATP production in spermatogonia from glycolysis to mitochondrial respiration, accompanied by increased levels of reactive oxygen species. In addition, inhibition of glucose conversion to glucose-6-phosphate or pentose phosphate pathway blocked the formation of c-Kit+ differentiating germ cells, suggesting that metabolites produced from glycolysis are required for spermatogonial differentiation. We further demonstrated that the expression levels of several metabolic regulators and enzymes were significantly altered upon retinoic acid-induced differentiation by both RNA-seq analyses and quantitative proteomics. Taken together, our data unveil a critically regulated bioenergetic balance between glycolysis and mitochondrial respiration which is required for spermatogonial proliferation and differentiation.
Project description:Retinoic acid triggers differentiation of spermatogonial stem cells by activating the expression of differentiating genes. Long noncoding RNAs (lncRNA) are transcripts longer than 200 nucleotides that do not code for proteins, providing a new perspective of RNA species in gene regulation. However, the function of lncRNAs in determining SSC differentiation has not been investigated. Here, we used high-throughput sequencing to profile all lncRNAs in SSCs, and report the dataset of lncRNAs during SSC differentiation.
Project description:Spermatogonial differentiation is a developmental process that is essential for spermatogenesis, but the molecular and cellular changes that germ cells must undergo to transition from undifferentiated spermatogonia to differentiating spermatogonia remain largely undefined. Retinoic acid (RA) is necessary and sufficient for spermatogonial differentiation. Using the postnatal mouse testis, we examine the transcriptome changes that accompany spermatogonial differentiation. Spermatogenesis was synchronized by administration of potent and selective RA synthesis inhibitor; as a result, testes contained only undifferentiated spermatogonia. Then, the inhibitor was discontinued, and mice were given a single dose of exogenous RA to initiate spermatogonial differentiation. We measured transcriptomes in FACS-enriched germ cells either before RA administration, when the cells correspond to Aal spermatogonia (and a minor contribution of spermatogonial stem cells) or at two points after RA administration, when the cells correspond to A1 or A3 differentiating spermatogonia. The results of this study reveal the full transcriptome changes accompanying spermatogonial differentiation in the mouse.
Project description:Among its many roles in development, retinoic acid determines the anterior-posterior identity of differentiating motor neurons by activating Retinoic Acid Receptor (RAR)-mediated transcription. RAR is thought to bind the genome constitutively, and only induce transcription in the presence of the retinoid ligand. However, little is known about where RAR binds to the genome or how it selects target sites. We tested the constitutive RAR binding model using the retinoic acid-driven differentiation of mouse embryonic stem cells into differentiated motor neurons. We find that retinoic acid treatment results in widespread changes in RAR genomic binding, including novel binding to genes directly responsible for anterior-posterior specification, as well as the subsequent recruitment of the basal polymerase machinery. Finally, we discovered that the binding of transcription factors at the embryonic stem cell stage can accurately predict where in the genome RAR binds after initial differentiation. We have characterized a ligand-dependent shift in RAR genomic occupancy at the initiation of neurogenesis. Our data also suggests that enhancers active in pluripotent embryonic stem cells may be preselecting regions that will be activated by RAR during neuronal differentiation. The differentiation of ventral motor neurons is induced by treating embryonic stem cell cultures with retinoic acid. Here, ChIP-seq is used to profile the genome-wide occupancy of RAR isofroms both immediately prior to and during exposure of the cells to retinoic acid. ChIP-seq is also used to profile the genomic occupancy of Pol2 with phosphorylated serine 5 (Pol2-S5P) and phosphorylated serine 2 (Pol2-S2P) after exposure to retinoic acid.
Project description:Functional analysis of transcriptome (mRNA and microRNA) and proteome formation during treatment of cord-blood derived stem cell lines (USSC) with retinoic acid-containing XXL-medium to estimate the impact of microRNAs on final proteome.
Project description:Functional analysis of transcriptome (mRNA and microRNA) and proteome formation during treatment of cord-blood derived stem cell lines (USSC) with retinoic acid-containing XXL-medium to estimate the impact of microRNAs on final proteome.