InDel mutations within the bovine PER2 gene are significantly associated with reproductive traits.

Functioning as a key regulator of circadian rhythms, the PER2 gene exerts a substantial impact on the reproductive traits of animals. However, the effect of the PER2 gene on ovarian development remains unclear. In order to examine the relationship between bovine reproductive trait and the PER2 gene, a total of 901 ovarian samples were collected, categorized into different oestrus cycles (proestrus, oestrus, post-oestrus, anoestrous), and subjected to analysis for two potential insertion/deletions (InDels) in the PER2 gene. Through agarose gel electrophoresis and DNA sequencing, two polymorphic deletion mutations (P2-D5-bp, P3-D13-bp) were identified. Furthermore, a significant association between mature follicle diameter and P2-D5-bp was found (P < 0.05). Additionally, several significant correlations with ovarian length, width, height, and white body diameter were found for P3-D13-bp (P < 0.05). These findings suggested that the bovine PER2 gene plays an important role in above-mentioned reproductive traits, offering new avenues for improving cow fertility through marker-assisted selection (MAS).

Regulation of myogenic cell proliferation and differentiation during mammalian skeletal myogenesis.

Mammalian skeletal myogenesis is a complex process that allows precise control of myogenic cells' proliferation, differentiation, and fusion to form multinucleated, contractile, and functional muscle fibers. Typically, myogenic progenitors continue growth and division until acquiring a differentiated state, which then permanently leaves the cell cycle and enters terminal differentiation. These processes have been intensively studied using the skeletal muscle developing models in vitro and in vivo, uncovering a complex cellular intrinsic network during mammalian skeletal myogenesis containing transcription factors, translation factors, extracellular matrix, metabolites, and mechano-sensors. Examining the events and how they are knitted together will better understand skeletal myogenesis's molecular basis. This review describes various regulatory mechanisms and recent advances in myogenic cell proliferation and differentiation during mammalian skeletal myogenesis. We focus on significant cell cycle regulators, myogenic factors, and chromatin regulators impacting the coordination of the cell proliferation versus differentiation decision, which will better clarify the complex signaling underlying skeletal myogenesis.

Genetic variant of the sheep E2F8 gene and its associations with litter size.

The economic efficiency of sheep breeding, aiming to enhance productivity, is a focal point for improvement of sheep breeding. Recent studies highlight the involvement of the Early Region 2 Binding Factor transcription factor 8 (E2F8) gene in female reproduction. Our group's recent genome-wide association study (GWAS) emphasizes the potential impact of the E2F8 gene on prolificacy traits in Australian White sheep (AUW). Herein, the purpose of this study was to assess the correlation of the E2F8 gene with litter size in AUW sheep breed. This work encompassed 659 AUW sheep, subject to genotyping through PCR-based genotyping technology. Furthermore, the results of PCR-based genotyping showed significant associations between the P1-del-32bp bp InDel and the fourth and fifth parities litter size in AUW sheep; the litter size of those with genotype ID were superior compared to those with DD and II genotypes. Thus, these results indicate that the P1-del-32bp InDel within the E2F8 gene can be useful in marker-assisted selection (MAS) in sheep.

CircRNA Profiling Reveals CircPPARγ Modulates Adipogenic Differentiation via Sponging miR-92a-3p.

Adipogenesis describes the proliferation, differentiation, and apoptosis of mature adipocytes from primary adipocytes and is regulated by post-transcriptional modifications. Circular RNAs (circRNAs) play critical roles in mammalian development and physiology. However, the circRNA-mediated regulation of adipogenesis remains poorly understood. We profiled circRNA expression during bovine primary adipogenesis, detecting 16 circRNA candidates, including circPPARγ, which was abundant in the adipose tissue. Overexpression (overexpression plasmids) and interference (small interfering RNAs) with circPPARγ in bovine primary adipocytes, and proliferation, differentiation, and apoptosis were analyzed using EdU (5-ethynyl-2'-deoxyuridine) cell proliferation, cell counting kit-8, flow cytometry, TdT-mediated dUTP nick-end labeling apoptosis assay, Oil Red O staining, quantitative real-time PCR, and western blotting assays, which showed that circPPARγ facilitates adipocyte differentiation and inhibits proliferation and apoptosis. Dual-luciferase reporter assay and RNA immunoprecipitation assays indicated that circPPARγ binds miR-92a-3p and YinYang 1 (YY1). A novel regulatory pathway regulating adipogenesis and adipose deposition was revealed.

circSVIL regulates bovine myoblast development by inhibiting STAT1 phosphorylation.

Circular RNAs (circRNAs), a novel class of non-coding RNAs with a loop structure, have recently been shown to participate in various pathophysiological processes. However, the precise role of circRNAs in myoblasts remains unclear. In this report, circSVIL was screened and identified from our previous sequencing analysis; we then performed gain- and loss-of-function experiments on bovine myoblasts by CCK8, EdU, flow cytometry, qRT-PCR, and Western blotting. The results indicate that circSVIL facilitates bovine myoblast proliferation and inhibits cell apoptosis. Using mechanism assays such as bioinformatics prediction, RNA immunoprecipitation (RIP), and cytoplasmic separation, we demonstrate that circSVIL could interact with STAT1 and inhibit STAT1 phosphorylation, thereby restraining STAT1's nuclear translocation and affecting its downstream signal cascade. Our results may elucidate a new regulatory pathway for bovine skeletal muscle development.

Characterization and Transcriptome Analysis of Exosomal and Nonexosomal RNAs in Bovine Adipocytes.

Exosomes are endosome-derived extracellular vesicles that allow intercellular communication. However, the biological significance of adipocyte exosomal RNAs remains unclear. To determine the role of RNAs from bovine adipocytes and exosomes in bovine adipogenesis, exosomal and nonexosomal RNAs were extracted from three bovine primary white adipocyte samples and then profiles were generated using DNBSEQ/BGISEQ-500 technology. The RNAome of adipocytes consisted of 12,082 mRNAs, 8589 lncRNAs, and 378 miRNAs for a higher complexity that that detected in exosomes, with 1083 mRNAs, 105 lncRNAs, and 48 miRNAs. Exosomal miRNA-mRNA and lncRNA-miRNA-mRNA networks were constructed and enrichment analysis was performed to predict functional roles and regulatory mechanisms. Our study provides the first characterization of RNAs from bovine adipocyte and exosomes. The findings reveal that some RNAs are specifically packaged in adipocyte-derived exosomes, potentially enabling crosstalk between adipocytes and/or other cells that is mediated by exosomes. Our results greatly expand our understanding of exosomal RNAs from bovine adipocytes, and provide a reference for future functional investigations of adipocyte exosomal RNAs under normal physiological conditions.

Exosome biogenesis, secretion and function of exosomal miRNAs in skeletal muscle myogenesis.

Exosomes are membrane-bound extracellular vesicles that are produced in the endosomal compartment of most mammalian cell types and then released. Exosomes are effective carriers for the intercellular material transfer of material that can influence a series of physiological and pathological processes in recipient cells. Among loaded cargoes, non-coding RNAs (ncRNAs) vary for the exosome-producing cell and its homeostatic state, and characterization of the biogenesis and secretion of exosomal ncRNAs and the functions of these ncRNAs in skeletal muscle myogenesis remain preliminary. In this review, we will describe what is currently known of exosome biogenesis, release and uptake of exosomal ncRNAs, as well as the varied functions of exosomal miRNAs in skeletal muscle myogenesis.

The Circular RNA circHUWE1 Sponges the miR-29b-AKT3 Axis to Regulate Myoblast Development.

Myogenesis is controlled by a well-established transcriptional hierarchy that coordinates the activities of a set of muscle genes. Recently, roles in myogenesis have been described for non-coding RNAs, including a role of circular RNA (circRNA) to regulate muscle gene expression. However, the functions of circRNA and the underlying mechanism by which circRNAs affect myogenesis remain poorly understood. In this study, we analyzed circRNA high-throughput sequencing results of bovine skeletal muscle samples and constructed a circRNA-miRNA-mRNA network according to the competitive endogenous RNA (ceRNA) theory. The putative circHUWE1-miR-29b-AKT3 network was analyzed and its involvement in myogenesis was confirmed through a series of assays. To assess the potential function of this regulation, bovine myoblasts were infected with overexpression plasmids and small interfering RNAs (siRNAs) that target circHUWE1. Next, cell proliferation, apoptosis, and differentiation were analyzed using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, western blotting, and qRT-PCR assays. The results suggest that circHUWE1 facilitates bovine myoblast proliferation and inhibits cell apoptosis and differentiation. Next, bioinformatics, dual-luciferase reporter assay, and AGO2 RNA immunoprecipitation (RIP) approaches were used to verify the interaction between circHUWE1, miR-29b, and AKT3. Subsequently, we identified that circHUWE1 could directly interfere with the ability of miR-29b to relieve AKT3 suppression, which ultimately activates the AKT signaling pathway. These findings suggested a new regulatory pathway for bovine skeletal muscle development, and they also expand our understanding of circRNA functions in mammals.

Polymorphism in PLIN2 gene and its association with growth traits in Chinese native cattle.

Perilipin 2 (PLIN2) is a cytosolic protein that regulates intracellular lipid storage and mobilization. However, research reports of the relationship between PLIN2 gene and growth traits in cattle are rare. Here, five novel single nucleotide polymorphisms (SNPs)（g.3036G > C, g.3964C > T, g.6458G > T, g.6555C > T and g.8231G > A）were identified within the bovine PLIN2 gene using DNA sequencing and PCR-SSCP methods in 820 individuals from four Chinese indigenous bovine breeds. Overall, five common haplotypes were identified based on the 5 SNPs, with the most common haplotypes (GCGCG) occurring at a frequency of 69.0%. In addition, The 5 novel SNPs were associated with growth traits at 6, 12, 18 and 24 months in Nanyang population, and significant associations were found in body weight and heart girth. These results suggest that PLIN2 possibly is a strong candidate gene marker for body weight in cattle breeding program.

Biogenesis and ceRNA role of circular RNAs in skeletal muscle myogenesis.

Circular RNAs (circRNAs) are novel endogenous non-coding RNAs that are generated by reverse-splicing of precursor mRNA derived from various genes in mammals. Despite low expression, recent studies have shown that circRNA plays an important role in skeletal muscle myogenesis with competing endogenous RNA (ceRNA) functions. However, the potential regulatory role of circRNAs and interactions with miRNAs remain largely unexplored, and the function of circRNAs as miRNA sponges is not yet generally accepted. In this review, we outline the biogenesis and ceRNA mechanisms of circRNAs as well as their involvement in skeletal muscle myogenesis and discuss the conflicting conclusions of recent circRNA-ceRNA studies.