Reproductive senescence in laying hens, characterized by a progressive decline in egg production, represents a major challenge for the poultry industry. Although microRNAs (miRNAs) are recognized as important regulators of aging, their specific roles and mechanisms in ovarian aging of hens remain largely unclear. This study was designed to comprehensively analyze miRNA expression patterns during ovarian aging in laying hens. The objectives of this study were to identify key functional miRNAs and to elucidate their molecular regulatory mechanisms. Specifically, this study evaluated ovarian senescence in hens at 350, 500 and 700 days of age, observing a decline in egg production, increased follicular atresia, and p53 upregulation. miRNA sequencing analysis identified 44 differentially expressed miRNAs (DEMs), among which gga-let-7i exhibited the highest abundance and showed progressive upregulation during aging. Functional assays revealed that gga-let-7i induces cell cycle arrest and promotes cellular senescence in ovarian follicle granulosa cells (GCs). Mechanistically, collagen type I alpha 2 chain (COL1A2) was confirmed as a direct target of gga-let-7i, and it has been demonstrated that gga-let-7i accelerates senescence by inhibiting the COL1A2/PI3K/AKT/MDM2 pathway, resulting in p53 accumulation and the downstream cellular senescence signaling pathways activation. These results uncover a novel gga-let-7i/COL1A2 regulatory axis involved in ovarian aging and suggest potential targets for extending reproductive longevity in laying hens.

INTRODUCTION:Residual feed intake (RFI) is a key indicator of feed efficiency in poultry and is regulated by coordinated physiological processes across multiple tissues. Improving feed efficiency is essential for sustainable poultry production; however, its genetic and molecular basis, particularly the relationship between feed efficiency and fat deposition during the extended laying period, remains incompletely understood. OBJECTIVES:This study aimed to identify the molecular features underlying feed efficiency and to elucidate its molecular relationship with fat deposition during the extended laying period in laying hens. METHODS:Whole-genome resequencing was integrated with multi-tissue transcriptomic and metabolomic profiling of 248 laying hens. Genetic association analyses, multi-tissue cis-eQTL mapping, cross-omics integration analyses, and molecular subtyping were combined with machine learning and hepatocyte-based functional assays to prioritize and evaluate candidate genes and metabolites associated with RFI at 100 weeks of age (100wRFI). RESULTS:Genetic analyses highlighted a genomic locus associated with 100wRFI. Integrative multi-omics analyses prioritized putative causal genes and metabolites across tissues, among which PCCB emerged as a recurrent multi-tissue candidate forming a liver-centered gene-metabolite-phenotype axis with PE(18:0/20:4(8Z,11Z,14Z,17Z)). Functional perturbation of PCCB in hepatocytes was associated with altered hepatic lipogenesis, redox status, mitochondrial membrane potential, and inflammatory signaling. Multi-tissue molecular features associated with 100wRFI showed stable predictive performance for fat deposition-related traits, and lysophosphatidylinositol LPI(18:1) was identified as a putative metabolic mediator promoting hepatic lipid accumulation in vitro. CONCLUSIONS:This study delineates the tissue-resolved molecular landscape of feed efficiency in hens during the extended laying period and highlights hepatic regulatory networks linking lipid metabolism, cellular homeostasis, and feed efficiency. These findings underscore the close molecular coupling between feed efficiency and fat deposition and provide a resource and framework for future functional studies and strategies to improve feed efficiency.

Roosters play a crucial role in breeder chicken production. A decline in reproductive performance during the late breeding stage is a major factor limiting economic returns. Testosterone, a key hormone for maintaining secondary sexual characteristics and supporting spermatogenesis, is primarily synthesized and processed within mitochondria. With advancing age, mitochondrial function deteriorates in roosters, leading to reduced testosterone synthesis and impaired reproductive capacity. This study aimed to elucidate the mechanisms through which rest and sport affect the reproductive performance of aging roosters. A total of 36 Tianfu Pink roosters aged 110 weeks were allocated into three groups with three replicates per group. After a 4-week intervention involving rest and sport regimens, natural mating was conducted to collect reproductive performance data. The results showed that rest and sport exerted anti-inflammatory effects, significantly improved semen quality and hatching performance, increased serum levels of testosterone and gonadotropins, enhanced systemic antioxidant capacity, and markedly upregulated FUNDC1 expression in the testes. In primary chicken testicular interstitial cells, overexpression or knockdown of FUNDC1 significantly enhanced or suppressed mitochondrial function, as well as the expression of genes and proteins related to antioxidant defense and testosterone synthesis. Moreover, FUNDC1 overexpression alleviated rotenone-induced mitochondrial damage and restored testosterone synthesis in testicular interstitial cells. These findings suggest that sport may enhance testosterone synthesis in testicular interstitial cells by modulating FUNDC1 expression, thereby improving mitochondrial function and antioxidant defense. This study provides theoretical and technical insights for improving the reproductive performance of breeding roosters during the late production phase.

Ovarian aging in laying hens contributes significantly to the decline in egg production performance during the late laying period, and is accompanied by extensive remodeling of miRNA-mRNA interaction networks, which are critical post-transcriptional regulators during this process. In this study, we investigated the role of miR-30e-3p, which was previously identified as significantly upregulated during ovarian aging in laying hens, in granulosa cell (GC) senescence. To identify its downstream effectors, we performed mRNA transcriptome sequencing and screened for downregulated genes. Among potential targets, the histone methyltransferase complex regulatory subunit dpy-30 (DPY30) was validated as a direct target of miR-30e-3p by luciferase reporter and expression analyses. Functional assays demonstrated that miR-30e-3p significantly suppressed GC proliferation and induced cell cycle arrest, whereas DPY30 exhibited opposite effects. Furthermore, inhibition of miR-30e-3p or overexpression of DPY30 attenuated D-galactose (D-gal) -induced GC senescence. Mechanistically, miR-30e-3p promoted cellular senescence at least in part through downregulation of DPY30. Collectively, our findings indicated that miR-30e-3p promotes GC senescence by targeting DPY30 in chicken ovarian follicles, and suggest that both miR-30e-3p and DPY30 may serve as potential biomarkers for improving reproductive longevity and mitigating ovarian aging-related disorders in poultry.

Tea polyphenols (TPs), bioactive secondary metabolites from Camellia sinensis, demonstrate significant potential for enhancing poultry reproductive efficiency. This 43-week study systematically evaluated graded TPs supplementation (0-500 mg/kg Food Weight) in Tianfu G02 Blue-shell roosters (n = 540) through growth monitoring, histopathological analysis (Hematoxylin and Eosin staining, H&E), and molecular profiling (ELISA, qPCR). The data were analyzed using a sampling T-test or ANOVA and Tukey's Test. Optimal growth performance was achieved at 100-400 mg/kg TP doses, improved daily feed intake and weight gain. The 200 mg/kg cohort exhibited peak spermatogenic capacity at week 28 (sperm density, P < 0.05) and week 43 (motility, P < 0.05), while 300 mg/kg enhanced sperm viability. Paradoxically, 500 mg/kg impaired reproductive parameters (the lowest sperm density, motility and viability). Testicular morphology revealed dose-dependent effects: 300-400 mg/kg groups showed seminiferous tubule expansion with concomitant testosterone elevation. Molecular analyses demonstrated TPs-mediated upregulation of androgen pathway genes (AR, Pgk2, P < 0.05) and antioxidant enhancement (MDA reduction, SOD/GSH-Px activation, P < 0.05). Immune modulation was evidenced by 200 mg/kg-induced immunoglobulin elevation (IgM, IgA, P < 0.05) and cytokine upregulation (IL-1β, IL-2, P < 0.05). Intestinal barrier integrity improved via ZO-1 and Claudin3 expression in 200-300 mg/kg groups (P < 0.05). These findings establish 200-300 mg/kg TPs as the optimal dosage window for enhancing rooster productivity, while cautioning against supra-nutritional (>400 mg/kg) applications.

The reproductive performance of hens is predominantly determined by the growth and development of their follicles. Follicular development in chickens represents a highly complex and multi-regulatory biological process, wherein granulosa cells (GCs) play a crucial role in follicle selection. Recent studies have emphasized the critical role of circular RNAs (circRNAs) in regulating follicular growth and development in animals. In our previous study, employing circRNA RNA-seq, we identified differential expression of circRALGPS2 between healthy and atretic follicles in chickens. In the current investigation, we observed a marked increase in autophagy and apoptosis levels within atretic follicles. Notably, circRALGPS2 was shown to promote follicular atresia by enhancing autophagy and apoptosis in GCs. Moreover, we demonstrated that circRALGPS2 functions as a molecular sponge for miR-200a-3p, revealing that miR-200a-3p and circRALGPS2 exert antagonistic effects on GC autophagy and apoptosis. Mechanistically, circRALGPS2 targets miR-200a-3p, which subsequently modulates the expression of transforming growth factor β2 (TGFβ2), thereby activating the canonical TGFβ/SMAD signaling pathway. Collectively, our findings demonstrate that circRALGPS2 promotes apoptosis and autophagy in chicken GCs through activation of the TGFβ2/SMAD pathway via miR-200a-3p sequestration. These results provide valuable insights for advancing chicken genetic breeding technologies through marker-assisted selection.

BACKGROUND:Programmed cell death plays a critical role in skeletal muscle atrophy. Ferroptosis, an iron-dependent form of programmed cell death driven by lipid peroxidation, has been implicated in various diseases, but its role in skeletal muscle atrophy remains unclear. METHODS:Ferroptosis in skeletal muscle atrophy was investigated using two models: dexamethasone (Dex)-induced atrophy (n = 6 independent cell cultures per group) and simulated microgravity (n = 6 mice per group). Conditional Nestin knockout (KO) mice were generated using CRISPR/Cas9 (n = 6-8 mice per group), with wild-type (WT) controls (n = 6-8). Phenotypic analyses included histopathology (HE staining), functional assessments (muscle strength, weight analysis, treadmill), and dystrophy evaluation (dystrophin staining). Molecular analyses involved flow cytometry, ELISA, transmission electron microscopy, PI staining, and IP/MS to delineate Nestin-regulated ferroptosis pathways in skeletal muscle atrophy. RESULTS:Ferroptosis was significantly activated in both atrophy models, with a 2.5-fold increase in lipid peroxidation (p < 0.01), a 2-fold accumulation of Fe2+ (p < 0.01) and a 50% reduction in Nestin expression (p < 0.001). Nestin KO mice exhibited exacerbated muscle atrophy, showing a 40% decrease in muscle weight (p < 0.01) and a 30% reduction in muscle strength (p < 0.05) compared to WT mice. Nestin overexpression mitigated Dex-induced ferroptosis, reducing lipid peroxidation by 40%, decreasing Fe2+ accumulation by 50% (p < 0.01), and improving muscle function by 30% (p < 0.05). Mechanistically, Nestin interacted with MAP 1LC3B (LC3B) to catalyse LC3B polyubiquitination at lysine-51, reducing LC3B availability for autophagy and inhibiting autophagy flux by 60% (p < 0.01), leading to a 50% reduction in ferroptosis (p < 0.001). CONCLUSIONS:Our study identifies Nestin as a critical regulator of ferroptosis-autophagy crosstalk in skeletal muscle atrophy. Targeting Nestin-LC3B ubiquitination may offer novel therapeutic strategies for preventing muscle wasting in diseases such as cachexia and sarcopenia.

Due to the complex environment of caged chicken coops, uneven illumination and severe occlusion in the coops lead to unsatisfactory accuracy of chicken detection. In this study, we construct an image dataset in the production environment of caged chickens using a head and neck co-annotation method and a multi-stage co-enhancement strategy, and we propose Chicken-YOLO, an occlusion-aware caged chicken detection model based on multi-scale edge information extractor and context fusion for the severe occlusion and poor illumination situations. The model enhances chicken feather texture and crown contour features via the multi-scale edge information extractor (MSEIExtractor), optimizes downsampling information retention through integrated context-guided downsampling (CGDown), and improves occlusion perception using the detection head with the multi-scale separation and enhancement attention module (DHMSEAM). Experiments demonstrate that Chicken-YOLO achieves the best detection performance among mainstream models, exhibiting 1.7% and 1.6% improvements in mAP50 and mAP50:95, respectively, over the baseline model YOLO11n. Moreover, the improved model achieves higher mAP50 than the superior YOLO11s while using only 58.8% of its parameters and 42.3% of its computational cost. On the two specialized test sets—one for poor illumination cases and the other for multiple occlusion cases—Chicken-YOLO’s performance improves significantly, with mAP50 increasing by 3.0% and 1.8%, respectively. This suggests that the model enhances target capture capability under poor illumination and maintains better contour continuity in occlusion cases, verifying its robustness against complex disturbances.

Programmed cell death (PCD), including autophagy, apoptosis, and ferroptosis, is a fundamental biological process that plays a critical role in follicular development and atresia in livestock. In ovaries, the vast majority of follicles undergo atresia, while only a small fraction reach ovulation. Emerging evidence suggests that these three forms of PCD are intricately involved in regulating follicular fate through distinct yet interconnected molecular mechanisms. This review summarizes recent advances in understanding the roles of autophagy, apoptosis, and ferroptosis in follicular development and atresia, with a focus on their molecular mechanisms and interactions. By elucidating the complex regulatory networks of PCD in ovarian physiology, this review aims to provide new insights into improving reproductive efficiency in livestock through targeted modulation of these pathways.

Non-alcoholic fatty liver disease (NAFLD) is a clinical syndrome characterized primarily by hepatocellular steatosis and lipid accumulation, which leads to hepatocyte apoptosis, autophagy, inflammation, and intracellular oxidative stress. NAFLD is recognized as one of the most prevalent and complex chronic liver diseases globally, with its occurrence and associated mortality rates rising swiftly each year. Due to the high similarity between chicken fatty liver syndrome (FLS) and NAFLD, as well as the easy availability of diseased chickens, the chicken is considered an ideal model for studying the pathogenesis of NAFLD. Previous studies have pinpointed several circular RNAs (circRNAs) implicated in the pathogenesis of NAFLD, yet the underlying functions and mechanisms of numerous circRNAs continue to remain elusive. In this experiment, we utilized circRNA sequencing of chicken livers to identify a novel circRNA, named circACACA, and discovered that it disrupts the metabolic homeostasis of lipids within hepatocytes. Consequently, this disruption leads to oxidative stress and the induction of autophagy, ultimately exerting an adverse effect on chicken liver health. Mechanistically, circACACA functions as a molecular sponge for miR-132b-5p and miR-101-2-5p to modulate the expression of the downstream CBFB/PIM1 complex. Consequently, it influenced the activity of the AKT/mTOR and PPAR-γ signaling pathways to perform its physiological functions. Crucially, we noticed substantial sequence similarity of circACACA across diverse species by comprehensively searching databases. Further, our research with a mouse model confirmed that the functional conservation of circACACA across livers of different species. Overall, this study built a mechanistic network for circACACA and confirmed its sequence conservation and functional relevance across various species. Our results not only provide new targets for the prevention and treatment of NAFLD but also present fresh perspectives for progress in healthy production of laying hens.

BACKGROUND:Uterine aging is a key factor contributing to the deterioration of egg quality and reproductive performance in laying hens. Despite its importance, the molecular mechanisms underlying uterine aging remain poorly defined. This study aimed to characterize gene expression and regulatory changes associated with uterine aging in hens at different life stages. RESULTS:Transcriptomic Analysis of uterine tissue from hens aged 350, 500, And 700 d revealed dynamic changes in gene expression patterns during aging. A significant upregulation of genes involved in cellular senescence was observed, including increased expression of the p53 signaling pathway And markers associated with inflammation And cell cycle arrest. The most notable changes occurred between 350 And 500 d of age, suggesting this as a critical window for the onset of uterine aging. MicroRNA sequencing identified miR-210a-5p as significantly reduced with age. Target prediction and experimental validation showed that miR-210a-5p directly suppresses the expression of RASL11B, a Ras-like small GTPase that activates the MAPK signaling pathway. In primary uterine epithelial cells, reduced miR-210a-5p levels led to elevated RASL11B expression, increased activation of B-Raf, MEK, and ERK proteins, and enhanced expression of aging-related genes and inflammatory factors. In contrast, overexpression of miR-210a-5p or inhibition of the MAPK pathway delayed senescence and reduced inflammatory signaling. RASL11B overexpression was sufficient to induce aging phenotypes, confirming its central role in promoting uterine cellular aging. CONCLUSIONS:This study identifies a novel regulatory pathway in which miR-210a-5p modulates uterine aging through the RASL11B-MAPK signaling cascade. The findings provide mechanistic insight into age-related reproductive decline in hens and suggest that targeting this pathway may offer new strategies for maintaining uterine function and extending reproductive lifespan in poultry.

BACKGROUND:Follicular atresia, a complex degenerative process regulated by multiple molecular mechanisms, significantly affects female reproductive performance in animals. While granulosa cell (GC) apoptosis has been well established as a primary mechanism underlying follicular atresia, the potential involvement of ferroptosis, which is an iron-dependent form of regulated cell death, remains largely unexplored in chickens. RESULTS:Using a tamoxifen (TMX)-induced avian model of follicular atresia, we demonstrated that ferroptosis plays a critical role in follicular degeneration. Inhibition of ferroptosis through pharmacological agents significantly restored follicular function, underscoring its potential as a therapeutic target. Notably, we observed a significant upregulation of ubiquitin-specific peptidase 9, X-linked (USP9X) in GCs during atresia. Through comprehensive in vitro and in vivo investigations, we confirmed that USP9X facilitates follicular atresia by promoting ferroptosis in GCs. Mechanistically, USP9X induces ferroptosis by stabilizing Beclin1 through deubiquitination, thereby activating autophagy-dependent ferroptosis. This pathway was effectively suppressed by autophagy inhibitors, emphasizing the essential role of autophagy in USP9X-mediated ferroptosis. CONCLUSIONS:Our findings provide the evidence that the USP9X-Beclin1 axis regulates autophagy-dependent ferroptosis during avian follicular atresia. These insights reveal novel molecular targets and potential genetic markers for improving reproductive efficiency in chicken breeding programs.

Natural mating colony cages are crucial in poultry breeding, yet breed-specific management requires further investigation. We evaluated the effects of sex ratios, stocking densities, and cohabitation age on Lohmann Pink-shell breeders’ performance. A total of 6126 birds were randomly allocated to experimental groups with varying ratios (1:8–1:13), densities (582–748 cm2/bird), and cohabitation ages (120/140 days), each containing six replicates. We monitored male mating frequencies at 50 weeks in 1:8 and 1:10 ratio groups. All 120-day-old groups showed delayed production onset and superior male weight compliance (p < 0.01), with reduced egg breakage and increased healthy chick output (p < 0.01). Lower stocking densities (748/694 cm2/bird) showed lower breakage rate and uniformity than 582 cm2/bird (p < 0.05). The 1:10 sex ratio achieved optimal egg production and fertilization rate (p < 0.05). Male mating peaked between 16:00 and 18:00. Optimal parameters were 120-day age of cohabitation, 694 cm2/bird density, and 1:10 sex ratio, providing theoretical guidance for natural mating colony cage development in layer breeding.

The liver is vital for laying hens, metabolizing nutrients, detoxifying, producing bile for digestion, regulating energy, and synthesizing yolk precursors, directly impacting egg production and health. MicroRNAs (MiRNAs) serve as central hepatic regulators, particularly influencing egg-laying efficiency through metabolic pathway control, detoxification modulation, and vitellogenesis. While miR-363-5p is implicated in liver metabolism and development across species, its specific roles in avian hepatic function remain underexplored. This study demonstrated that miR-363-5p induces lipogenesis, oxidative stress, and inflammation in chicken hepatocytes. Additionally, this study defined the interaction mechanism between miR-363-5p and its target genes and verified the cytoplasmic-polyadenylation element binding protein 2 (CPEB2) as a target gene of miR-363-5p using dual-luciferase assays. It was also confirmed that the effect of CPEB2 knockdown on hepatocytes was the same as that of miR-363-5p overexpression, including enhanced lipogenesis, elevated oxidative stress, and pronounced inflammatory responses. Furthermore, we confirmed that the miR-363-5p/CPEB2 axis modulates the MAPK/ERK signaling pathway, contributing to hepatic steatosis in chickens. Our findings establish a novel miR-363-5p/CPEB2/MAPK regulatory axis in avian lipid metabolism, providing new insights into the pathogenesis of fatty liver disease in poultry.

Circular RNAs (circRNAs) are a class of endogenous non-coding RNAs that have been implicated in mediating granulosa cell (GC) proliferation and apoptosis. CircRAB11A was found to have a significantly higher expression in normal follicles compared to atrophic follicles. In this study, we determined that the knockdown of circRAB11A resulted in the inhibition of proliferation and promotion of apoptosis in GCs of chicken. Moreover, circRAB11A was found to act as a sponge for miR-24-5p, both member RAS oncogene family (RAB11A) and epidermal growth factor receptor (EGFR) were revealed to be targets of miR-24-5p through a dual-luciferase reporter assay. RAB11A or EGFR promoted proliferation and suppressed apoptosis in GCs through the phosphatidylinositol-kinase (PI3K)/AKT or extracellular signal-regulated kinase (ERK)1/2 pathway. These findings suggest that circRAB11A may function as a competing endogenous RNA (ceRNA) by targeting the miR-24-5p/RAB11A and miR-24-5p/EGFR axes and activating the ERK1/2 and PI3K/AKT pathways, offering a potential avenue for exploring the mechanism of follicle development.

Granulosa cells play a pivotal role in growth, development and ovulation of ovarian follicle. Simultaneously, autophagy and apoptosis processes are crucial determinants in the destiny of granulosa cells. Within this context, miR-29-3p, known to regulate a broad spectrum of biological processes and critical for tumor detection, prognosis, and treatment, is poised to clarify its roles in both autophagy and apoptosis. To enhance the understanding of the influence of miR-29-3p on follicular development, our study primarily delved into the realms autophagy and apoptosis. We employed a well-established chicken follicular atrophy model achieved through subcutaneous injection of tamoxifen (TMX) into hens. qPCR analysis revealed a significant decrease in the expression of miR-29-3p within the atrophic follicles. In our in vitro experiments with cultured chicken primary granulosa cells, miR-29-3p emerged as a novel microRNA capable of impeding autophagy and apoptosis when transfected with miR-29-3p mimics and inhibitors. Results from luciferase reporter assays corroborated that PTEN is a legitimate target of miR-29-3p. Unlike miR-29-3p, PTEN appeared to foster autophagy and apoptosis in chicken granulosa cells. Moreover, our findings uncovered that miR-29-3p facilitates the phosphorylation of Akt and mTOR proteins by targeting PTEN in chicken granulosa cells. In conclusion, the findings of this study suggest that miR-29-3p, through its targeting of PTEN via the Akt/mTOR signaling pathway, exerts inhibitory effects on autophagy and apoptosis. These effects may hold significant importance in the context of follicular development.

MicroRNAs (miRNAs) have been demonstrated to control chicken skeletal muscle growth, however, the potential function of the miR-181-5p family in chicken myogenesis remains largely unknown. Here, our study identified the two chicken (Gallus gallus; Gga) miR-181-5p family members widely expressed in various tissues, specifically miR-181a-5p and miR-181b-5p. Besides, the breast muscles of fast-growing broilers expressed higher levels of miR-181a-5p and miR-181b-5p than those of slow-growing layers. Functionally, miR-181a-5p and miR-181b-5p both promote the expression level of myogenic factors including Myogenin (MyoG), Myogenic differentiation 1 (MyoD1), and Myosin heavy chain (MyHC), meanwhile accelerating the myotube formation of skeletal muscle satellite cells (SMSCs). Mechanistically, miR-181a-5p and miR-181b-5p directly bind to the 3' Untranslated region (UTR) of the Transforming growth factor beta receptor 1 (TGFBR1) mRNA, further reducing the expression of TGFBR1. TGFBR1 is a key Transforming growth factor beta (TGF-β) signaling transduction receptor and had a negative function in muscle cell differentiation. Furthermore, knockdown of TGFBR1 facilitated the expression of chicken myogenic factors, boosted myotube formation, and decreased the SMAD family member 2/3 (SMAD2/3) phosphorylation in chicken SMSCs. SMAD2/3 are downstream of TGF-β signaling, and miR-181a-5p and miR-181b-5p could reduce the expression of TGFBR1 to further diminish the SMAD2/3 phosphorylation. Our findings revealed that the miR-181-5p family targets TGFBR1 to break the TGF-β signaling transduction, which resulted in promoting chicken skeletal muscle development.

Ovarian follicle development is an important physiological activity for females and makes great significance in maintaining female health and reproduction performance. The development of ovarian follicle is mainly affected by the granulosa cells (GCs), whose growth is regulated by a variety of factors. Here, we identified a novel circular RNA (circRNA) derived from the Ribosomal protein S19 (RPS19) gene, named circRPS19, which is differentially expressed during chicken ovarian follicle development. Further explorations identified that circRPS19 promotes GCs proliferation and steroid hormone synthesis. Furthermore, circRPS19 was found to target and regulate miR-218-5p through a competitive manner with endogenous RNA (ceRNA). Functionals investigation revealed that miR-218-5p attenuates GCs proliferation and steroidogenesis, which is opposite to that of circRPS19. In addition, we also confirmed that circRPS19 upregulates the expression of Inhibin beta B subunit (INHBB) by binding with miR-218-5p to facilitate GCs proliferation and steroidogenesis. Overall, this study revealed that circRPS19 regulates GCs development by releasing the repression of miR-218-5p on INHBB, which suggests a novel mechanism in respect to circRNA and miRNA regulation in ovarian follicle development.

This study aimed to compare the effects of various selenium (Se) sources (2 mg/kg) on the performance, quality, and antioxidant capacity of laying hens as well as the Se content in their eggs and blood. We selected 720 34-wk-old Lohmann pink-shell laying hens were randomly assigned into 6 groups and fed a basal diet (control) or a basal diet supplemented with various Se sources (Se-enriched yeast, SY-A, SY-C, SY-N; selenomethionine SM, nano-Se SN) for 16 wk. There were 10 replicates of 120 hens per group. Dietary Se supplementation increased the egg production rate of all laying hens. Egg and serum Se deposition was highest in the SM group. Yolk color scores of SY-A and SY-N groups were significantly lower than those of other groups (P < 0.01). The protein height and Haugh unit were significantly lower in the SN group than in the other groups (P < 0.05). The yolk height was significantly higher in the SN and SY-N groups than in the SY-A group (P < 0.05). Dietary supplementation of selenium can improve the antioxidant capacity of laying hens. The SOD content of SM group was significantly lower than that of SY-A and SN group (P < 0.05). The malondialdehyde (MDA) content was significantly higher in the SM group than in the SY-A group (P < 0.05). The present work empirically demonstrated that the production performance of laying hens supplemented with 2 mg/kg Se was superior to that of the hens receiving only a basal diet. The SY-C group exhibited the best production performance, the SY-A group had the highest antioxidant capacity, and the SM group produced eggs with the highest level of Se enrichment.

Circular RNAs have emerged as critical regulators of gene expression across various biological systems. In this study, circAGO3, originating from exons 5, 6, 7, and 8 of the AGO3 gene in chickens, is characterized for its stability and differential expression during both embryonic and post-hatch stages. Overexpression of circAGO3 in chicken skeletal muscle markedly disrupts myogenesis by downregulating muscle differentiation markers and upregulating genes associated with muscle atrophy. RNA sequencing and functional analyses further delineate circAGO3's involvement in modulating inflammatory responses through the NF-κB signaling pathway, mediated by its interaction with miR-34b-5p. These findings highlight circAGO3's potential importance in poultry production by uncovering its regulatory roles in skeletal muscle development and inflammation, positioning it as a promising target for enhancing muscle growth and health in poultry farming.