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Assisted reproduction technology (ART) procedures are often impacted by post-ovulatory aging (POA), which can lead to reduced fertilization rates and impaired embryo development. This study used RNA sequencing analysis and experimental validation to study the similarities and differences between in vivo- and vitro-matured porcine oocytes before and after POA. Differentially expressed genes (DEGs) between fresh in vivo-matured oocyte (F_vivo) and aged in vivo-matured oocyte (A_vivo) and DEGs between fresh in vitro-matured oocyte (F_vitro) and aged in vitro-matured oocyte (A_vitro) were intersected to explore the co-effects of POA. It was found that "organelles", especially "mitochondria", were significantly enriched Gene Ontology (GO) terms. The expression of genes related to the "electron transport chain" and "cell redox homeostasis" pathways related to mitochondrial function significantly showed low expression patterns in both A_vivo and A_vitro groups. Weighted correlation network analysis was carried out to explore gene expression modules specific to A_vivo. Trait–module association analysis showed that the red modules were most associated with in vivo aging. There are 959 genes in the red module, mainly enriched in "RNA binding", "mRNA metabolic process", etc., as well as in GO terms, and "spliceosome" and "nucleotide excision repair" pathways. DNAJC7, IK, and DDX18 were at the hub of the gene regulatory network. Subsequently, the functions of DDX18 and DNAJC7 were verified by knocking down their expression at the germinal vesicle (GV) and Metaphase II (MII) stages, respectively. Knockdown at the GV stage caused cell cycle disorders and increase the rate of abnormal spindle. Knockdown at the MII stage resulted in the inefficiency of the antioxidant melatonin, increasing the level of intracellular oxidative stress, and in mitochondrial dysfunction. In summary, POA affects the organelle function of oocytes. A_vivo oocytes have some unique gene expression patterns. These genes may be potential anti-aging targets. This study provides a better understanding of the detailed mechanism of POA and potential strategies for improving the success rates of assisted reproductive technologies in pigs and other mammalian species. [ABSTRACT FROM AUTHOR]

BACKGROUND Red bed sandstone is a set of continental or shallow lake clastic rocks in the Danxia landform. Accurate determination of Fe(Ⅱ) and Fe(Ⅲ) in red bed sandstone that indicates the redox relationship during weathering can serve as the dividing basis of weathering degree and depth of the block. During the determination of iron content by phenanthroline spectrophotometry, Fe(Ⅱ) is easily oxidized and the result is a lower value than it should be. Effective prevention of oxidation is the focus of accurate measurement of Fe(Ⅱ) and Fe(Ⅲ) content. OBJECTIVES To explore the preservation method of Fe(Ⅱ) during dissolution and establish a spectrophotometric method for the determination of Fe(Ⅱ) and total iron in red sandstone. METHODS Color reagents were added in the samples, and the samples were dissolved by hydrofluoric acid and dilute sulfuric acid, in a constant temperature water bath at 90℃. Hydroxylamine hydrochloride was used as a reducing agent, o-phenanthroline was used as a chromogenic agent, pH was adjusted by acetate-ammonium acetate buffer, and trace Fe(Ⅱ) and total iron were determined by spectrophotometer. RESULTS The detection limit of Fe(Ⅱ) was 0.002%, relative standard deviation (RSD, n=8) was less than 2%, and the standard recovery was between 92.6% and 94.7%. The Fe(Ⅱ) content of red sandstone in the Danxia landform area of Chishui was determined by this analysis method. The content of Fe(Ⅱ) ranged from 0.01% to 0.1%, the total iron content was 0.7%-1.5%, and the content of Fe(Ⅲ) calculated by subtraction was 0.7%-1.5%. The measurement results were consistent with those of X-ray fluorescence spectrometry and potassium complexate titration method. CONCLUSIONS This method uses developer and hydrofluoric acid-dilute sulfuric acid to dissolve the samples, which can effectively preserve the original Fe(Ⅱ) in sandstone. The same solution can be used for the determination of both total iron and Fe(Ⅱ) which provides a simple and accurate analysis method for various types of iron content in red bed sandstone.

Highly active oxygen evolution reaction (OER) electrocatalysts, such as those containing Fe, often face the challenge of severe dissolution of active elements. Addressing this concern through the establishment of a dynamically stable interface during OER presents a promising strategy, achieved by manipulation of catalyst components. Herein, the findings reveal that Fe loss during OER predominantly occurs during the initial activation phase, marked by irreversible structural distortion that disrupts interfacial dynamical stability. By investigating the structural evolution of Fe‐containing Prussian blue analogs, serving as a model OER precatalyst, the correlation between precatalyst structural changes and interfacial dynamic stability is elucidated. Utilizing thermal annealing of CoFe bimetal Prussian blue, favorable thermodynamic conditions are induced for generating cyano vacancies within the matrix, thereby facilitating enhanced initial activation during OER. Consequently, catalytically active and stable oxyhydroxide species rapidly form at the interface, exhibiting robust interactions with interfacial Fe elements to stabilize interface dynamics. Suppression of the irreversible structural distortion responsible for active element loss during initial activation culminates in enhanced OER activity and stability. [ABSTRACT FROM AUTHOR]

Y‐box binding protein 1 (YBX1) is a member of the family of DNA‐ and RNA‐binding proteins that play crucial roles in multiple aspects, including RNA stabilization, translational repression, and transcriptional regulation; however, its roles in embryo development remain less known. In this study, to investigate the function of YBX1 and its mechanism of action in porcine embryo development, YBX1 was knocked down by microinjecting YBX1 siRNA at the one‐cell stage. YBX1 is located in the cytoplasm during embryonic development. The mRNA level of YBX1 was increased from the four‐cell stage to the blastocyst stage but was significantly decreased in YBX1 knockdown embryos compared with the control. Moreover, the percentage of blastocysts was decreased following YBX1 knockdown compared with the control. Defecting YBX1 expression increased maternal gene mRNA expression and decreased zygotic genome activation (ZGA) gene mRNA expression and histone modification owing to decreased levels of N6‐methyladenosine (m6A) writer N6‐adenosine‐methyltransferase 70 kDa subunit (METTL3) and reader insulin‐like growth factor 2 mRNA‐binding protein (IGF2BP1). In addition, IGF2BP1 knockdown showed that YBX1 regulated the ZGA process through m6A modification. In conclusion, YBX1 is essential for early embryo development because it regulates the ZGA process. [ABSTRACT FROM AUTHOR]

Background: Activating transcription factor 7 (ATF7) is a member of the ATF/cAMP response element (CRE) B superfamily. ATF2, ATF7, and CRE‐BPa are present in vertebrates. Drosophila and fission yeast have only one homologue: dATF2 and Atf1, respectively. Under normal conditions, ATF7 promotes heterochromatin formation by recruiting histone H3K9 di‐ and tri‐methyltransferases. Once the situation changes, all members are phosphorylated by the stress‐activated kinase P38 in response to various stressors. However, the role of ATF7 in early porcine embryonic development remains unclear. Results: In this study, we found that ATF7 gradually accumulated in the nucleus and then localized on the pericentric heterochromatin after the late 4‐cell stage, while being co‐localized with heterochromatin protein 1 (HP1). Knockdown of ATF7 resulted in decreases in the blastocyst rate and blastocyst cell number. ATF7 depletion resulted in downregulation of HP1 and histone 3 lysine 9 dimethylation (H3K9me2) expression. These effects were alleviated when P38 activity was inhibited. High temperatures increased the expression level of pP38, while reducing the quality of porcine embryos, and led to ATF7 phosphorylation. The expression level of H3K9me2 and HP1 was decreased and regulated by P38 activity. Conclusion: Stress‐induced ATF7‐dependent epigenetic changes play important roles in early porcine embryonic development. [ABSTRACT FROM AUTHOR]