Copy number variation is a part of genomic structural variation and has caused widespread concern. According to the results of high-throughput screening of the MLLT10 gene, we found that the copy number variation region of the MLLT10 gene was correlated with bovine growth traits. We aimed to detect the MLLT10 gene copy number variation and provide materials for the Chinese yellow cattle breed. In this study, the SPSS software was used to analyze the correlation among the copy number type of six different cattle breeds (i.e., Qinchuan, Xianan, Jiaxian, Yanbian, Sinan, Yunling) and the corresponding growth traits. The results showed the following: In Qinchuan cattle, the copy number duplication type was greater than the deletion and normal types; in Xianan cattle, the copy number duplication and normal types were less as compared with the deletion type; and in Yunling cattle, the frequency of the duplication type was dominant among the three types of copy number variants. The correlation analysis result showed that there is a significant correlation between the copy number variation (CNV) of the MLLT10 gene and the growth traits of three cattle breeds. Furthermore, correlation analysis showed that MLLT10 CNV had positive effects on growth traits such as hip width, rump length, hucklebone width, and cannon bone circumference (p < 0.05). This study provides a basis for the molecular-assisted marker breeding of cattle and contributes to the breeding of cattle.

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.

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.

Heat stress is a critical environmental factor that compromises reproductive performance in dairy cattle, primarily through deleterious effects on ovarian follicular cells. Granulosa cells (GCs), which provide essential nutritional and hormonal support for oocyte maturation, are particularly vulnerable to hyperthermic insult. However, the early molecular and subcellular events that precede overt cellular dysfunction remain inadequately characterized. This study aimed to investigate the temporal dynamics of mitochondrial morphological alterations and transcriptomic reprogramming in bovine GCs subjected to acute in vitro heat stress. Bovine GCs were exposed to 43 °C for 10, 20, 30, or 40 min, with untreated cells serving as controls. Heat shock protein expression (HSP90 and HSPA1A) was evaluated by qRT-PCR. Intracellular calcium concentration was measured using the Fluo-3 AM fluorescent probe. Mitochondrial ultrastructure was examined via transmission electron microscopy (TEM). Global transcriptional changes were profiled by RNA sequencing (RNA-seq) at 20 and 40 min post-treatment, followed by bioinformatics analysis. Nine selected differentially expressed genes (DEGs) were validated by qRT-PCR. HSP90 and HSPA1A expression was significantly upregulated at 30 and 40 min of heat exposure (p < 0.05). Intracellular Ca²⁺ concentration exhibited a biphasic pattern—markedly elevated at 20 min but significantly reduced at 40 min. TEM revealed progressive mitochondrial swelling and cristae disruption at both time points, with more severe damage at 40 min. RNA-seq identified 185 DEGs at 20 min and 831 DEGs at 40 min, with 285 genes commonly dysregulated across both time points. Functional enrichment analysis demonstrated that the 20-min response was dominated by heat shock protein-related pathways, whereas the 40-min response expanded to encompass apoptosis, inflammation, steroidogenesis, and ciliogenesis pathways. qRT-PCR validation confirmed the reliability of the RNA-seq data. These findings provide a mechanistic framework for understanding heat stress-induced ovarian dysfunction and may inform strategies to preserve fertility in dairy cattle during thermal challenge.