Lipopolysaccharide (LPS) is one of the main factors inducing endometritis in dairy cows. However, the specific pathogenesis of LPS-induced endometritis in dairy cows is not fully understood. The objective of this study was to establish an in vitro endometritis model using LPS-induced bovine endometrial epithelial (BEND) cells. BEND cells were treated with LPS of different concentrations and times. The cell-counting kit-8 (CCK-8) was used to detect the cell survival rate after LPS treatment, and quantitative real-time PCR (RT-qPCR) was used to detect the expression of control group and LPS-treated group of inflammatory factors interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-α). The results showed that the survival rate of endometrial epithelial cells stimulated by 5 μg/mL LPS for 6 h was 75.13%, and the expression of inflammatory factors was significantly increased. Therefore, 5 μg/mL LPS for 6 h could be selected as a suitable model for the study of inflammation. In addition, miRNA sequencing and target gene prediction was performed on normal and LPS-treated BEND cells. Among twenty-one differentially expressed miRNAs, six miRNAs were selected and their expression levels were detected by RT-qPCR, which were consistent with the sequencing results. Twenty-one differentially expressed miRNAs collectively predicted 17,050 target genes. This study provides a theoretical basis for further investigation of the pathogenesis of endometritis.

Numerous dynamic and complicated processes characterize development from the oocyte to the embryo. However, given the importance of functional transcriptome profiles, long non-coding RNAs, single-nucleotide polymorphisms, and alternative splicing during embryonic development, the effect that these features have on the blastomeres of 2-, 4-, 8-, 16-cell, and morula stages of development has not been studied. Here, we carried out experiments to identify and functionally analyze the transcriptome profiles, long non-coding RNAs, single-nucleotide polymorphisms (SNPs), and alternative splicing (AS) of cells from sheep from the oocyte to the blastocyst developmental stages. We found between the oocyte and zygote groups significantly down-regulated genes and the second-largest change in gene expression occurred between the 8- and 16-cell stages. We used various methods to construct a profile to characterize cellular and molecular features and systematically analyze the related GO and KEGG profile of cells of all stages from the oocyte to the blastocyst. This large-scale, single-cell atlas provides key cellular information and will likely assist clinical studies in improving preimplantation genetic diagnosis.

To improve the vitrification efficiency of bovine germinal vesicle (GV) oocytes, the use of hydroxyapatite (HA) nanoparticles as a novel cryopreservation additive represents a promising approach. This study aimed to investigate the effects of HA nanoparticles and permeable cryoprotective agents (CPAs) on the ultrastructure, developmental competence, and gene expression of bovine GV oocytes following vitrification. Oocytes were vitrified in vitrification solutions containing HA nanoparticles of different sizes (20, 40, or 60 nm) and concentrations (0.01%, 0.05%, or 0.1%) to determine the optimal conditions based on survival rate, mitochondrial membrane potential (MMP) level, and developmental competence. Subsequently, the synergistic effects of HA nanoparticles and permeable CPAs (VS: 20% EG + 20% DMSO; VS1: 17.5% EG + 17.5% DMSO) were further evaluated. The optimal treatment (40 nm 0.05% HA nanoparticles) significantly increased MMP level, and improved developmental competence compared with the vitrified control group (p < 0.05). Among the vitrified groups, vitrified oocytes in the VS1-HA group (combining HA nanoparticles with reduced concentrations of permeable CPAs) exhibited the highest MMP level (1.89), maturation rate (50.39%), cleavage rate (27.07%), and blastocyst rate (10.53%) (p < 0.05). Ultrastructural analysis further revealed that the VS1-HA group maintained more intact zona pellucida structures and showed reduced mitochondrial swelling compared with the vitrified control group. Moreover, the expression levels of genes associated with zona pellucida formation (ZP3), mitochondrial fusion (MFN1), and chromatin remodeling (NPM2) were significantly upregulated in the VS1-HA group relative to the vitrified control group. Overall, these findings indicate that the combination of HA nanoparticles with lower concentrations of permeable CPAs enhances MMP level, alleviates vitrification-induced ultrastructural damage, and upregulates the expression of key developmental genes, thereby improving the developmental competence of vitrified bovine GV oocytes.

DNA polymerase β (DNA polymerase beta (POLB)) belongs to a member of the DNA polymerase X family, mainly involved in various biological metabolic processes, such as eukaryotic DNA replication, DNA damage repair, gene recombination, and cell cycle regulation. In this study, the muscle development-related gene POLB was screened by selection signature and RNA-seq analysis and then validated for the proliferation and apoptosis of bovine primary myocytes. It was also found that overexpression of the POLB gene had a pro-apoptosis effect, but interfering with the expression of the gene had no significant effect on cells. Then, the analysis of related apoptotic genes revealed that POLB overexpression affected CASP9 gene expression.

Numerous dynamic and complicated processes characterize development from the oocyte to the embryo. However, given the importance of functional transcriptome profiles, long non-coding RNAs, single-nucleotide polymorphisms, and alternative splicing during embryonic development, the effect that these features have on the blastomeres of 2-, 4-, 8-, 16-cell, and morula stages of development have not been studied. Here, we conducted a scRNA-seq survey of cells from sheep from the oocyte to the blastocyst developmental stages. We then carried out experiments to identify and functionally analyze the transcriptome profiles, long non-coding RNAs, single-nucleotide polymorphisms (SNPs), and alternative splicing (AS). We founded that between the oocyte and zygote groups significantly down-regulated genes and the second-largest change in gene expression occurred between the 8- and 16-cell stages. We used various methods to construct a profile to characterize cellular and molecular features and systematically analyze the related GO and KEGG profile of cells of all stages from the oocyte to the blastocyst. This large-scale, single-cell atlas provides key cellular information and will likely assist clinical studies in improving preimplantation genetic diagnosis.

Plasma exosomes have been identified to be involved in embryo development and implantation. In this study, the plasma exosomes of seven pregnant cows on day 16 and seven non-pregnant cows were collected. Exosome miRNA profiles were revealed by RNA sequencing technology and the abundance of exosome miRNA between them were compared. Seven miRNAs were significantly differently expressed (p-value < 0.05, |log2(FoldChange)| > 1), with five miRNAs upregulated and two downregulated in the pregnant cow group. The most significant miRNA was bta-miR-136 (downregulated in pregnant cows, p-value < 0.005). A total of 5828 target genes were computationally predicted for the seven miRNAs. GO and KEGG enrichment analyses showed these targets were significantly involved in several biological processes and pathways associated with embryo implantation and endometrial development, such as cell adhesion, cell junction, focal adhesion, Ras signaling pathway and Rap1 signaling pathway. This study identifies seven differentially expressed plasma exosomes miRNAs on day 16 of pregnancy in cows, with bta-miR-136, bta-miR-199b, and bta-miR-382-3p emerging as candidate miRNAs for future studies on maternal–fetal communication and embryo implantation.