Search

Avian primordial germ cells (PGCs) are important culture cells for the production of transgenic chickens and preservation of the genetic resources of endangered species; however, culturing these cells in vitro proves challenging. Although the proliferation of chicken PGCs is dependent on insulin, the underlying molecular mechanisms remain unclear. In the present study, we explored the expression of the PI3K/AKT signaling pathway in PGCs, investigated its effects on PGC self-renewal and biological properties, and identified the underlying mechanisms. Our findings indicated that although supplementation with the PI3K/AKT activator IGF-1 failed to promote proliferation under the assessed culture conditions, the PI3K/AKT inhibitor LY294002 resulted in retarded cell proliferation and reduced expression of germ cell-related markers. We further demonstrated that inhibition of PI3K/AKT regulates the cell cycle and promotes apoptosis in PGCs by activating the expression of BAXand inhibiting that of Bcl-2. These findings indicated that the PI3K/AKT pathway is required for cell renewal, apoptosis, and maintenance of the reproductive potential in chicken PGCs. This study aimed to provide a theoretical basis for the optimization and improvement of a culture system for chicken PGCs and provide insights into the self-renewal of vertebrate PGCs as well as potential evolutionary changes in this unique cell population.

As an important posttranslational modification, ubiquitination plays an important role in regulating protein homeostasis in eukaryotic cells. In our previous studies, both the transcriptome and proteome suggested that ubiquitination is involved in the formation of chicken primordial germ cells (PGCs). Here, affinity enrichment combined with liquid chromatography–tandem mass spectrometry (MS/MS) was used to analyze the ubiquitome during the differentiation from embryonic stem cells to PGCs, and we identify that 724 lysine ubiquitinated sites were up-regulated in 558 proteins and 138 lysine ubiquitinated sites were down-regulated in 109 proteins. Furthermore, GO and KEGG enrichment analysis showed that ubiquitination regulates key proteins to participate in the progression of key events related to PGC formation and the transduction of key signals such as Wnt, MAPK, and insulin signals, followed by the detailed explanation of the specific regulatory mechanism of ubiquitination through the combined proteome and ubiquitome analysis. Moreover, both the activation and inhibition of neddylation were detrimental to the maintenance of the biological characteristics of PGCs, which also verified the importance of ubiquitination. In conclusion, this study provides a global view of the ubiquitome during the formation of PGCs by label‐free quantitative ubiquitomics, which lays a theoretical foundation for the formation mechanism and specific application of chicken PGCs.This study lays a theoretical foundation for the formation mechanism and specific application of chicken PGCs.Recently, the application potential of chicken primordial germ cells (PGCs) in fields like germplasm resource conservation has been emphasized. However, the incomplete understanding of the regulatory mechanisms during their formation makes it difficult to obtain PGCs in vitro efficiently, limiting their specific applications. As one of the most important posttranslational modifications, ubiquitination is widely involved in biological processes by regulating protein degradation, etc. However, only a few studies on the regulation of chicken PGC formation by ubiquitination have been conducted so far. Here, to explore the specific regulatory role of ubiquitination during PGC formation, we conducted label‐free quantitative ubiquitomics of chicken embryonic stem cells (ESCs) and PGCs. Meanwhile, the in vitro ubiquitination activation and inhibition experiments and the combined proteome and ubiquitome analysis were performed. The results of the ubiquitome analysis showed that ubiquitination plays a crucial role during PGC formation, which was also proved by the in vitro ubiquitination activation and inhibition experiments. Moreover, by combining the proteome and ubiquitome, we screened some key targets of ubiquitination. To sum up, our study suggests that ubiquitination is essential for chicken PGC formation by regulating key proteins to participate in key events or the transduction of key signals.

Germplasm resources are essential for the sustainable development of biodiversity and husbandry of local chickens, as well as for the breeding and industry of superior quality chickens. Unfortunately, many local and indigenous chicken breeds are at risk of declining numbers, emphasizing the need to conserve breed resources for endangered chickens. Primordial germ cells (PGCs) are crucial for preserving germplasm resources by inheriting genetic information from parents to offspring and ensuring stability of genetic material between germlines. In this study, PGCs were isolated from chicken embryos’ gonads and cultured in FAcs medium without feeder cells. Over a period of approximately 40 days, the cells proliferated to a number of up to 106, establishing various cell lines. Particularly, 18 PGC lines were created from Rugao Yellow Chicken and Shouguang Chicken, with an efficiency ranging from 39.1% to 45%. Furthermore, PGCs that had been cultured for 40 passages exhibited typical PGC characteristics, such as glycogen staining reaction, and expression of pluripotency and reproductive markers. These results confirm that PGCs maintain stem cell properties even after long-term in vitroculture. Additionally, PGCs cryopreserved for up to 120 days remained viable, maintained typical PGC morphologies, and possessed stable cell proliferation ability. Through intravascular injection into chicken embryos, green fluorescent protein (GFP)-PGCs were found in the recipient embryos’ gonads and could develop into gametes to produce offspring, indicating that even after extended culture, PGCs retain their migratory and lineage-transmitting capabilities. This research offers valuable insights into the in vitrocultivation and preservation of PGCs of Chinese indigenous chickens. The findings of this study can be applied in transgenic chicken production and the preservation of genetic resources of indigenous chicken breeds.

In the context of industrial CO2capture, the need for efficient solvent regeneration at lower temperatures poses a significant challenge. Catalyst-assisted enhancement of the CO2desorption kinetics has emerged as a potential solution. This study introduces a series of cost-effective and readily available sepiolite clay-based catalysts activated via simple acid treatments. This activation significantly enhances both the surface area and surface acidity, laying the foundation for more effective catalysts. Experimental results at a moderate temperature of 88 °C demonstrate the effectiveness of the prepared catalysts, resulting in remarkable improvements: up to a 163.6% increase in the CO2desorption rate, an up to 83.6% increase in the desorbed CO2quantity, and a reduction of up to 45.6% in heat duty compared with the baseline amine solution. Furthermore, the prepared catalysts exhibit facile separability through filtration and sustained stability over 10 cycles. To shed light on the underlying chemical processes, we also present a plausible reaction mechanism for the acid-activated sepiolite-catalyzed CO2desorption reaction. This research holds promise for environmentally friendly and cost-effective amine regeneration processes in CO2capture applications.

Homocysteine (Hcy) is an intermediate in the one-carbon metabolism that donates methyl groups for methylation processes involved in epigenetic gene regulation. Although poor oocyte quality in polycystic ovarian syndrome (PCOS) patients is associated with elevated Hcy concentration in serum and follicular fluid, whether Hcy directly affects oocyte quality and its mechanisms are poorly understood. Here we show that Hcy treatment impaired oocyte quality and developmental competence, indicated by significantly reduced survival rate, polar body extrusion rate, and cleavage rate. Hcy treatment resulted in mitochondrial dysfunction, with increased production of mitochondrial ROS, reduced mtDNA copy number, and the expression of 7 out of 13 mtDNA-encoded genes and 2 ribosome RNA genes, 12S rRNA and 16S rRNA. Upon Hcy treatment, the expression of one-carbon metabolic enzymes and DNMT1 was enhanced. Interestingly, DNA methyltransferase inhibitor 5'AZA rescued Hcy-induced mitochondrial dysfunction, impaired oocyte quality and developmental competence. Concurrently, expression of one-carbon metabolic enzymes and methylation status of mtDNA coding sequences were also normalized, at least partially, by 5'AZA treatment. Our findings not only extend the understanding about how Hcy induces poor oocyte quality, but also contribute to a novel angle of identifying targets for enhancing the quality of oocyte from PCOS patients.

With the benefits of fast curing under ambient conditions, space, energy efficiency, and high resolution patterns, ultraviolet (UV) curable resin has great potential in the domain of Aerosol-jet (AJ) printing (one form of direct write printing methods). However, the geometric and performance deviations between design and fabrication are commonly observed. The in-situcuring mechanism of UV curable microdroplets is found to significantly influence the fabrication resolution in both lateral and depth dimensions which are critical for fabricating complex structures in AJ printing. In this work, we developed a predictive model to reflect the in-situthermal-photopolymerization process of microdroplets in AJ printing through the finite element analysis (FEA) method and analyzed the influence of substrate temperature on the printing morphology, the distribution of velocity, monomer concentration as well as degree of curing (DOC) in the microdroplets through the combination of experiment and simulation and realized the correlation between the microdroplet curing process and the printing geometry. The simulation results obtained by the prediction model are consistent with the variation trend of printed ink streams under the influence of substrate temperature, and the errors in the direction of line width are within the range of 2.3%−7.9%. It may have important application value in realizing morphology control and improving fabrication controllability in AJ printing.

Three-dimensional (3D) conformal printing of temperature sensors with a wide sensing range and high stability requires the potential printable material with excellent functionality and printability. Herein, a high-performance silver nanoparticles (Ag NPs) decorated reduced graphene oxide (RGO)/Ag (ADR/Ag) ink with low viscosity was synthesized for aerosol jet printing (AJP). Ag ions are electrostatically adsorbed on the graphene oxide (GO) surface, and Ag NPs (∼10 nm) were attached onto the RGO surface by in-situliquid-phase reduction. The ADR nanoflakes were mixed with commercial Ag NPs ink, high resolution patterns with ink stream widths down to 10 μm are printed, and ADR/Ag-0.8% ink shows excellent low-temperature sintering capability and flexibility, and the resistivity of the printed traces is 9.79 × 10−5 Ω m after 1 h sintering at a relatively low temperature (75 °C). The resistance negligibly increases by only 5% after 1000 bending cycles, which is about 7 times lower compared to the pure Ag traces. Furthermore, we achieve the 3D printing of a conformal temperature sensor with a sensitivity range of (1.162–1.519) × 10−3/°C in the broad sensing range of 0–200 °C. These findings shed light on the additive manufacturing of high-performance conformal electronics using the emerging AJP technology.

Spermatogonia Stem Cells (SSCs) are the basis of spermatogenesis. In the poultry industry, asthenospermia and azoospermia in roosters seriously reduce economic benefits. In this study, we explored SSC formation mechanisms in detail. TDRD1, which is a downstream target gene of TCF7L2 and is modified by histone methylation, was screened through multi-omics analysis. Functionally, RT-qPCR, flow cytometry, immunohistochemistry, and indirect immunofluorescence results showed that H3K4me2 regulated TDRD1 to promote SSC formation both in vivoand in vitro. Furthermore, ChIP-qPCR and dual luciferase assays showed that H3K4me2 was enriched in the -800-0 bp region of the TDRD1promoter and positively regulated TDRD1transcription to promote SSC formation. Interestingly, in mechanistic terms, dual luciferase assays showed that TDRD1transcription levels were significantly decreased after co-transfection with dCas9-LSD1-P1/P2/P3 and OETCF7L2, while TDRD1transcript levels were not significantly altered after transfecting dCas9-LSD1-P4 and OETCF7L2. These results suggest that H3K4me2 enrichment in P1, P2, and P3 of the TDRD1promoter promotes TDRD1transcription by reducing enrichment of TCF7L2. This study explored the specific regulatory mechanisms involving the Wnt signaling pathway, H3K4me2, and TDRD1, enriched the regulatory network regulating the formation of SSCs, and laid a theoretical foundation for the specific application of SSCs.

Getting intimate:A 3D interconnected Bi0.5Sr0.5FeO3−δ(BSF)–Ag electrocatalyst is prepared from a BSF–AgNO3core–shell precursor in one step. The nanometer‐sized Ag enhances the sintering process, enabling an optimum cathode microstructure and good cathode‐to‐electrolyte attachment upon firing at 850 °C. A solid‐oxide fuel cell based on this cathode shows a near 100 % peak power density enhancement at 550 °C.

In this work the oxygen reduction reaction on (BSF) and (LSF) as cathodes for intermediate temperature solid oxide fuel cells is compared in detail. Partial substitution of Sr in with of Bi or La results in the distinct structural features which strongly impact its electrochemical characteristics due to the presence of a lone electron pair in , which is not available in . Cubic structure for BSF favours higher ionic conductivity and enhanced formation of oxygen vacancies relative to rhombohedral structure for LSF. Large oxygen nonstoichiometry for BSF, nevertheless, leads to the dominance of and subsequent low electronic conductivity relative to LSF. It was found that upon cathodic polarization, the oxygen vacancies are created on LSF which helps reducing its interfacial resistance afterward, which is not the case for BSF. Overall, BSF demonstrates good electrochemical performance which can be further optimized by enhancing its electronic conductivity.

In this work the oxygen reduction reaction on Bi0.5Sr0.5FeO3−δ(BSF) and La0.5Sr0.5FeO3−δ(LSF) as cathodes for intermediate temperature solid oxide fuel cells (600–750°C)is compared in detail. Partial substitution of Sr in SrFeO3−δwith 50mole%of Bi or La results in the distinct structural features which strongly impact its electrochemical characteristics due to the presence of a lone electron pair in Bi3+, which is not available in La3+. Cubic structure for BSF favours higher ionic conductivity and enhanced formation of oxygen vacancies relative to rhombohedral structure for LSF. Large oxygen nonstoichiometry for BSF, nevertheless, leads to the dominance of Fe3+and subsequent low electronic conductivity relative to LSF. It was found that upon cathodic polarization, the oxygen vacancies are created on LSF which helps reducing its interfacial resistance afterward, which is not the case for BSF. Overall, BSF demonstrates good electrochemical performance which can be further optimized by enhancing its electronic conductivity.