Identification of key events and regulatory networks in the formation process of primordial germ cell based on proteomics.

Currently, studies have analyzed the formation mechanism of primordial germ cell (PGC) at the transcriptional level, but few at the protein level, which made the mechanism study of PGC formation not systematic. Here, we screened differential expression proteins (DEPs) regulated PGC formation by label-free proteomics with a novel sampling strategy of embryonic stem cells and PGC. Analysis of DEPs showed that multiple key events were involved, such as the transition from glycolysis to oxidative phosphorylation, activation of autophagy, low DNA methylation ensured the normal formation of PGC, beyond that, protein ubiquitination also played an important role in PGC formation. Importantly, the progression of such events was attributed to the inconsistency between transcription and translation. Interestingly, MAPK, PPAR, Wnt, and JAK signaling pathways not only interact with each other but also interact with different events to participate in the formation of PGC, which formed the PGC regulatory network. According to the regulatory network, the efficiency of PGC formation in induction system can be significantly improved. In conclusion, our results indicate that chicken PGC formation is a complex process involving multiple events and signals, which provide technical support for the specific application in PGC research.

The Establishment and Optimization of a Chicken Primordial Germ Cell Induction Model Using Small-Molecule Compounds.

In recent years, inducing pluripotent stem cells to differentiate into functional primordial germ cells (PGCs) in vitro has become an important method of obtaining a large number of PGCs. However, the instability and low induction efficiency of the in vitro PGC induction system restrict the application of PGCs in transgenic animal production, germplasm resource conservation and other fields. In this study, we successfully established a two-step induction model of chicken PGCs in vitro, which significantly improved the formation efficiency of PGC-like cells (PGCLCs). To further improve the PGC formation efficiency in vitro, 5025 differentially expressed genes (DEGs) were obtained between embryonic stem cells (ESCs) and PGCs through RNA-seq. GO and KEGG enrichment analysis revealed that signaling pathways such as BMP4, Wnt and Notch were significantly activated during PGC formation, similar to other species. In addition, we noted that cAMP was activated during PGC formation, while MAPK was suppressed. Based on the results of our analysis, we found that the PGC formation efficiency was significantly improved after activating Wnt and inhibiting MAPK, and was lower than after activating cAMP. To sum up, in this study, we successfully established a two-step induction model of chicken PGCs in vitro with high PGC formation efficiency, which lays a theoretical foundation for further demonstrating the regulatory mechanism of PGCs and realizing their specific applications.

Mechanisms of Embryonic Stem Cell Pluripotency Maintenance and Their Application in Livestock and Poultry Breeding.

Embryonic stem cells (ESCs) are remarkably undifferentiated cells that originate from the inner cell mass of the blastocyst. They possess the ability to self-renew and differentiate into multiple cell types, making them invaluable in diverse applications such as disease modeling and the creation of transgenic animals. In recent years, as agricultural practices have evolved from traditional to biological breeding, it has become clear that pluripotent stem cells (PSCs), either ESCs or induced pluripotent stem cells (iPSCs), are optimal for continually screening suitable cellular materials. However, the technologies for long-term in vitro culture or establishment of cell lines for PSCs in livestock are still immature, and research progress is uneven, which poses challenges for the application of PSCs in various fields. The establishment of a robust in vitro system for these cells is critically dependent on understanding their pluripotency maintenance mechanisms. It is believed that the combined effects of pluripotent transcription factors, pivotal signaling pathways, and epigenetic regulation contribute to maintaining their pluripotent state, forming a comprehensive regulatory network. This article will delve into the primary mechanisms underlying the maintenance of pluripotency in PSCs and elaborate on the applications of PSCs in the field of livestock.

DDX5 Can Act as a Transcription Factor Participating in the Formation of Chicken PGCs by Targeting BMP4.

As an RNA binding protein (RBP), DDX5 is widely involved in the regulation of various biological activities. While recent studies have confirmed that DDX5 can act as a transcriptional cofactor that is involved in the formation of gametes, few studies have investigated whether DDX5 can be used as a transcription factor to regulate the formation of primordial germ cells (PGCs). In this study, we found that DDX5 was significantly up-regulated during chicken PGC formation. Under different PGC induction models, the overexpression of DDX5 not only up-regulates PGC markers but also significantly improves the formation efficiency of primordial germ cell-like cells (PGCLC). Conversely, the inhibition of DDX5 expression can significantly inhibit both the expression of PGC markers and PGCLC formation efficiency. The effect of DDX5 on PGC formation in vivo was consistent with that seen in vitro. Interestingly, DDX5 not only participates in the formation of PGCs but also positively regulates their migration and proliferation. In the process of studying the mechanism by which DDX5 regulates PGC formation, we found that DDX5 acts as a transcription factor to bind to the promoter region of BMP4-a key gene for PGC formation-and activates the expression of BMP4. In summary, we confirm that DDX5 can act as a positive transcription factor to regulate the formation of PGCs in chickens. The obtained results not only enhance our understanding of the way in which DDX5 regulates the development of germ cells but also provide a new target for systematically optimizing the culture and induction system of PGCs in chickens in vitro.