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Simple Summary: The Lueyang black-bone chicken is a vital poultry resource originating from China. This study aimed to investigate the effects of different rearing systems on the meat quality of Lueyang black-bone chickens via untargeted metabolomics. Compared with caged rearing, cage-free rearing significantly reduced chicken carcass yield and increased the shear force of leg muscles. In addition, the cage-free rearing mode promoted the accumulation of nutrients, such as phospholipids, unsaturated fatty acids, glutamate, and adenosin 3′-monophosphate. Moreover, the cage-free rearing system also enhanced the accumulation of volatile organic compounds, such as aldehydes, alcohols, and ketones, which greatly contribute to the meat flavor. In summary, this study provides a theoretical basis for cage-free rearing as a better rearing mode for Lueyang black-bone chickens. The Lueyang black-bone chicken is a specific native chicken strain in China. This study aimed to investigate the effects of different rearing systems on the meat quality of Lueyang black-bone chickens. Six hundred Lueyang black-bone hens were randomly divided into two groups at 7 weeks of age and raised in cage and cage-free systems for 20 weeks. The carcass yield, meat quality, and total metabolites were measured in both the leg and breast muscles. By comparison, the carcass yield of hens in the cage-free (CF) group (1.26 ± 0.09 kg) was significantly lower than that in the caged rearing (CR) group (1.52 ± 0.15 kg). However, the shear force of leg muscles in the CF group (27.98 ± 2.43 N) was significantly greater than that in the CR group (24.15 ± 1.93 N). In addition, six samples from each group were randomly selected and their metabolites were detected by the non-targeted metabolomics technique. Among these metabolites, 408 and 354 significantly differentially abundant metabolites were identified in breast and leg muscles, which were mainly involved in glycerophospholipid metabolism, unsaturated fatty acid biosynthesis, arginine and proline metabolism, and nucleotide metabolism. We found that the levels of 19 phospholipids, mainly phosphatidylcholines and lysophosphatidylcholines, were significantly greater in the CF group than in the CR group. Additionally, the contents of eight unsaturated fatty acids, linoleic acid, and linolenic acid were dramatically greater in the CF group than in the caged group. The accumulation of 4-hydroxy-proline, glutamate, and adenosine 3′-monophosphate (AMP) was enhanced in the CF group. Moreover, many more volatile organic compounds were identified in the muscles of the cage-free group, enhancing the flavor of the chicken meat. In conclusion, the cage-free rearing mode facilitates the accumulation of nutrients and flavor substances in the chicken meat and is a better rearing system for Lueyang black-bone chickens. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is an endocrine disruptor with reproductive toxicity. Further, 1,25‐dihydroxyvitamin D3 (VD3) plays an important role in male reproduction by binding vitamin D receptor (VDR) and mediating the pleiotropic biological actions that include spermatogenesis. However, whether VD3/VDR regulates the effect of BPA on Leydig cells (LCs) injury remains unknown. This study aimed to explore the effects of VD on BPA‐induced cytotoxicity in mouse LCs. Hereby, LCs treated with BPA, VD3, or both were subjected to the assays of cell apoptosis, proliferation, autophagy, and levels of target proteins. This study unveiled that cell viability was dose‐dependently reduced after exposure to BPA. BPA treatment significantly inhibited LC proliferation, induced apoptosis, and also downregulated VDR expression. By jointly analyzing transcriptome data and Comparative Toxicogenomics Database (CTD) data, autophagy signaling pathways related to testicular development and male reproduction were screened out. Therefore, the autophagy phenomenon of cells was further detected. The results showed that BPA treatment could activate cell autophagy, Vdr−/− inhibits cell autophagy, and active VD3 does not have a significant effect on the autophagy of normal LCs. After VD3 and BPA were used in combination, the autophagy of cells was further enhanced, and VD3 could alleviate BPA‐induced damage of LCs. In conclusion, this study found that supplementing VD3 could eliminate the inhibition of BPA on VDR expression, further enhance LCs autophagy effect, and alleviate the inhibition of LCs proliferation and induction of apoptosis by BPA, playing a protective role in cells. The research results will provide valuable strategies to alleviate BPA‐induced reproductive toxicity. [ABSTRACT FROM AUTHOR]

Methyltransferase-like 21C (METTL21C) is a member of the non-histone methyltransferase superfamily, which mainly mediates the methylation of lysine (Lys) residues. The main types of modification are Lys dimethylation and trimethylation. However, at present, most of the studies on METTL21C are focused on humans and mice, and there are few reports on poultry. Therefore, chicken embryo fibroblasts (DF-1) were selected as the object of study. To explore the function of chicken METTL21C (chMETTL21C) in the proliferation of DF-1 cells, flow cytometry and qPCR were used to detect the function of chicken METTL21C in the proliferation of DF-1 cells. The results showed that overexpression of METTL21C blocked the cell cycle in the G1max S phase, thus inhibiting cell proliferation. In addition, based on proteomic analysis, stable overexpression of METTL21C may inhibit the proliferation of DF-1 cells by mediating lysine trimethylation of proliferation-related proteins phosphorylated adapter RNA export protein (PHAX), nucleoside diphosphate kinases (NDPKs), eukaryotic transcription extension factor (eukaryotic translation elongation factor 1A,e EF1A), and inversin (Invs). Through immunoprecipitation (co-IP) and liquid chromatography-mass spectrometry (LC-MS/MS) analysis, METTL21C-mediated PHAX Lys-381 methylation was confirmed to be involved in the regulation of DF-1 cell proliferation. The results of this study provide a reference for analyzing the methylation function of METTL21C and the mechanism of regulating the growth and development of chicken cells. [ABSTRACT FROM AUTHOR]

Skeletal muscle has an essential role in boiler production, which depends on the muscle fibre development during the embryonic stage. Whereas the posttranslational modifications of both histone and non-histone proteins are known to regulate postnatal muscle development, the biological significance of non-histone methylation is poorly understood. Recently, the methyltransferase like 21 C (METTL21C) is identified as a non-histone lysine methyltransferase whose role in chicken muscle function remains elusive. In this study, METTL21C was found by comparing free-range and caged modes in Lueyang black-boned chicken aged 60 and 120 days. Quantitative real-time PCR (qPCR) analysis demonstrated that METTL21C was mainly enriched in chicken soleus (SOL) and gastrocnemius muscle (GA) (p <.05). Meanwhile, METTL21C had a rapid increase during chicken myoblast differentiation. After METTL21C overexpression, myogenic differentiation (MyoD) and myogenin (MyoG) expression were significantly increased, indicating that METTL21C promotes chicken myoblast differentiation. Using co-immunoprecipitation (Co-IP) and liquid chromatography-mass spectrometry (LC-MS/MS) analysis, heat shock cognate 71 kDa protein (Hsc70) was confirmed to interact with METTL21C, while the effects of Hsc70 Lys-561 (Hsc70 K561) mutation suggested that Hsc70 was a METTL21C target protein. These results identify the molecular mechanism of METTL21C interaction with Hsc70 associated with chicken myoblast differentiation in the postnatal period. The mRNA of methyltransferase like 21C (METTL21C) was significantly increased in free-rang mode and during the chicken myoblast differentiation. Overexpression of METTL21C promoted the primary chicken myoblasts proliferation and differentiation. METTL21C could mediate the lysine methylation modification of heat shock cognate 71 kDa protein (Hsc70) to regulate the proliferation of chicken myoblasts. [ABSTRACT FROM AUTHOR]

As a new type of environmental pollutant, micro-nano plastics (MNPs) are widely distributed and difficult to degrade. MNPs persist in organism and can also serve as carriers for other pollutants, facilitating the transfer of pollutants through the food chain. MNPs pose a potential serious threat to human health and have received extensive attention. While the toxicity of MNPs in aquatic animals has been studied extensively, the effects and mechanisms of MNPs in terrestrial mammals remain elusive. This review summarizes the accumulation, distribution, reproductive toxicity, neurotoxicity, induced inflammatory response and gut microbiota change of MNPs in animals. It also systematically analyzes the effects of MNPs on human health and identifies key risk factors of MNPs. Based on the previous findings and potential gaps, the review proposes future directions for the study of biological toxicity of MNPs. The aim is to contribute to the understanding of the toxicological mechanism, prevention of bio-hazards, toxic damage repair and the development of medicine in the field of MNPs. [ABSTRACT FROM AUTHOR]

Lueyang black-bone chicken is free-range in hilly areas and has unique genetic characteristics and excellent muscle quality. However, the molecular mechanisms of breeding mode influence growth and meat quality in Lueyang black-bone chicken are still unclear. Here we analyzed the meat quality and transcriptome data of thigh muscle by comparing free-range and caged modes at the age of 60 and 120 days in Lueyang black-boned chicken. The results demonstrated that the free-range mode could improve the pH value, tenderness, and reducing the hardness of the thigh muscle. Intramuscular fat (IMF) content of the thigh muscle was markedly higher in the caged chickens compared with free-range animals at the age of 60 days. Functional pathway analysis illustrated that tight junction signaling was associated with the formation of slow-twitch fibers in free-range chickens at age of 120 days. All research data proved that the free-range mode could improve muscle quality by promoting the formation of slow-twitch fibers and IMF in thigh muscle in Lueyang black-bone chicken. Based on the animal benefit and healthy, the free-range feeding should be considered during the breeding process of broiler chicken. The results provide good knowledge of the functional molecular mechanisms associated with muscle quality in Lueyang black-bone chicken. [ABSTRACT FROM AUTHOR]

Ningqiang pony is one of the five pony breeds in China and is listed as a rare species. It is, therefore, meaningful to conduct stature research on this breed for its efficient reproduction, utilization and protection. This study is based on four SNP variants of adjacent LCORL/NCAPG, HMGA2, ZFAT and LASP1 genes, which have been found to be associated with horse height, and then, the 4 SNP loci in 22 Ningqiang ponies were analyzed. The results showed that there were genetic variations at the four loci in Ningqiang pony, there was a SNP on LCORL/NCAPG, HMGA2 and ZFAT gene all including T allele and C allele and LASP1 including A allele and G allele. Further data analysis revealed that LCORL/NCAPG variant harbor the allele T and LASP1 variant harbor the allele G were significantly related to body height (p < 0.05). These findings suggested that the two SNP mutations within the LCORL/NCAPG and LASP1 genes could be considered as a screening marker for the body height of Ningqiang pony and could provide a new strategy for breeding and protect the rare germplasm resources. [ABSTRACT FROM AUTHOR]