Assembly of a pangenome for global cattle reveals missing sequences and novel structural variations, providing new insights into their diversity and evolutionary history.

A cattle pangenome representation was created based on the genome sequences of 898 cattle representing 57 breeds. The pangenome identified 83 Mb of sequence not found in the cattle reference genome, representing 3.1% novel sequence compared with the 2.71-Gb reference. A catalog of structural variants developed from this cattle population identified 3.3 million deletions, 0.12 million inversions, and 0.18 million duplications. Estimates of breed ancestry and hybridization between cattle breeds using insertion/deletions as markers were similar to those produced by single nucleotide polymorphism-based analysis. Hundreds of deletions were observed to have stratification based on subspecies and breed. For example, an insertion of a Bov-tA1 repeat element was identified in the first intron of the APPL2 gene and correlated with cattle breed geographic distribution. This insertion falls within a segment overlapping predicted enhancer and promoter regions of the gene, and could affect important traits such as immune response, olfactory functions, cell proliferation, and glucose metabolism in muscle. The results indicate that pangenomes are a valuable resource for studying diversity and evolutionary history, and help to delineate how domestication, trait-based breeding, and adaptive introgression have shaped the cattle genome.

The FSH-mTOR-CNP signaling axis initiates follicular antrum formation by regulating tight junction, ion pumps, and aquaporins.

The initial formation of the follicular antrum (iFFA) serves as a dividing line between gonadotropin-independent and gonadotropin-dependent folliculogenesis, enabling the follicle to sensitively respond to gonadotropins for its further development. However, the mechanism underlying iFFA remains elusive. Herein, we reported that iFFA is characterized by enhanced fluid absorption, energy consumption, secretion, and proliferation and shares a regulatory mechanism with blastula cavity formation. By use of bioinformatics analysis, follicular culture, RNA interference, and other techniques, we further demonstrated that the tight junction, ion pumps, and aquaporins are essential for follicular fluid accumulation during iFFA, as a deficiency of any one of these negatively impacts fluid accumulation and antrum formation. The intraovarian mammalian target of rapamycin-C-type natriuretic peptide pathway, activated by follicle-stimulating hormone, initiated iFFA by activating tight junction, ion pumps, and aquaporins. Building on this, we promoted iFFA by transiently activating mammalian target of rapamycin in cultured follicles and significantly increased oocyte yield. These findings represent a significant advancement in iFFA research, further enhancing our understanding of folliculogenesis in mammals.

Regulatory impacts of PPARGC1A gene expression on milk production and cellular metabolism in buffalo mammary epithelial cells.

The PPARGC1A gene plays a fundamental role in regulating cellular energy metabolism, including adaptive thermogenesis, mitochondrial biogenesis, adipogenesis, gluconeogenesis, and glucose/fatty acid metabolism. In a previous study, our group investigated seven SNPs in Mediterranean buffalo associated with milk production traits, and the current study builds on this research by exploring the regulatory influences of the PPARGC1A gene in buffalo mammary epithelial cells (BuMECs). Our findings revealed that knockdown of PPARGC1A gene expression significantly affected the growth of BuMECs, including proliferation, cell cycle, and apoptosis. Additionally, we observed downregulated triglyceride secretion after PPARGC1A knockdown. Furthermore, the critical genes related to milk production, including the STATS, BAD, P53, SREBF1, and XDH genes were upregulated after RNAi, while the FABP3 gene, was downregulated. Moreover, Silencing the PPARGC1A gene led to a significant downregulation of ß-casein synthesis in BuMECs. Our study provides evidence of the importance of the PPARGC1A gene in regulating cell growth, lipid, and protein metabolism in the buffalo mammary gland. In light of our previous research, the current study underscores the potential of this gene for improving milk production efficiency and overall dairy productivity in buffalo populations.

Maternal exposure to DON during lactation induces testicular toxicity in pubertal and adult offspring mice.

Deoxynivalenol (DON), a type B trichothecene mycotoxin, commonly occurs in cereal grains, and poses significant health risks to humans and animals. Numerous studies reveal its obvious toxic effects on male reproductive performance as well as its ability to transfer from the lactating mother to the suckling offspring through colostrum and milk. The objective of this study was to evaluate the toxic effect of lactational DON exposure on testicular morphology, hormonal levels, inflammation, apoptosis and proliferation of germ cells, tight junction, and sperm quality in male offspring. Sixty-six male offspring mice from lactating dams exposed to DON were euthanized at PND 21 and PND 70 to investigate the reproductive toxicity. Our results indicated that maternal DON exposure had a significant impact on the weight and volume of the testes, caused testicular histopathology, and reduced testosterone levels by downregulating expressions of StAR, CYP11A1, and CYP17A1 in male offspring. We also found that maternal DON exposure led to testicular inflammation in male offspring, which was attributed to increased levels of inflammatory markers, including IL-1ß, IL-6, TNF-α, and IFN-γ. Maternal DON exposure resulted in impaired tight junctions of Sertoli cells in male offspring, as evidenced by decreased expressions of ZO-1, Occludin, and Claudin-3. In addition, maternal DON exposure caused a reduction in the number of Sertoli cells and germ cells, ultimately leading to decreased sperm count and quality in adult male offspring. Collectively, these findings provide compelling evidence that maternal exposure to DON during lactation causes testicular toxicity in both pubertal and adult male offspring.

AS602801 treatment suppresses breast cancer metastasis to the brain by interfering with gap-junction communication by regulating Cx43 expression.

AS602801 has been reported as a potential drug candidate against brain metastasis by suppressing the gap-junction communication between lung cancer stem cells and astrocytes. In this study, we aimed to study the molecular mechanism underlying the role of AS602801 in the treatment of brain metastasis in breast cancer. We utilized female athymic BALB/c nude mice and MDA-MB-231/BT-474BR cells to establish experimental models. Polymerase chain reaction assays were performed to observe changes in the connexin 43 (Cx43) messenger RNA (mRNA) and c-Jun N-terminal kinase (JNK) mRNA levels. Dye transfer assay was used to observe the effect of AS602801 on cell-cell communication. An organotypic blood-brain barrier (BBB) model was utilized to observe the effect of AS602801 on transmigration through the BBB barrier. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and flow cytometry were performed to evaluate the proliferation and apoptosis of breast cancer cells co-cultivated with astrocytes. AS602801 inhibited the upregulation of Cx43 and JNK in brain metastasized breast cancer cells in a dose-dependent manner. Also, AS602801 significantly decreased the dye transfer rate from astrocytes to breast cancer cells, indicating the inhibitory effect of AS602801 on cell-cell communication. The transmigration ability of breast cancer cells co-cultured with astrocytes was decreased by AS602801. Furthermore, AS602801 reduced the elevated Cx43/JNK mRNA expression in the co-astrocyte group while suppressing the increased proliferation and promoting the decreased apoptosis of breast cancer cells co-cultivated with astrocytes. AS602801 also suppressed the brain metastasis of breast cancer cells and increased mouse survival. AS602801 downregulates the expressions of JNK and Cx43 to suppress the gap-junction activity. AS602801 also inhibits the communication between breast cancer cells and astrocytes, thus contributing to the treatment of brain metastasis in breast cancer.

A Molecular Perspective and Role of NAD+ in Ovarian Aging.

The decline in female fecundity is linked to advancing chronological age. The ovarian reserve diminishes in quantity and quality as women age, impacting reproductive efficiency and the aging process in the rest of the body. NAD+ is an essential coenzyme in cellular energy production, metabolism, cell signaling, and survival. It is involved in aging and is linked to various age-related conditions. Hallmarks associated with aging, diseases, and metabolic dysfunctions can significantly affect fertility by disturbing the delicate relationship between energy metabolism and female reproduction. Enzymes such as sirtuins, PARPs, and CD38 play essential roles in NAD+ biology, which actively consume NAD+ in their enzymatic activities. In recent years, NAD+ has gained much attention for its role in aging and age-related diseases like cancer, Alzheimer's, cardiovascular diseases, and neurodegenerative disorders, highlighting its involvement in various pathophysiological processes. However, its impact on female reproduction is not well understood. This review aims to bridge this knowledge gap by comprehensively exploring the complex interplay between NAD+ biology and female reproductive aging and providing valuable information that could help develop plans to improve women's reproductive health and prevent fertility issues.

Integrating mid-infrared spectroscopy, machine learning, and graphical bias correction for fatty acid prediction in water buffalo milk.

BACKGROUND: Buffalo milk, constituting 15% of global production, has higher fatty acids content than Holstein milk. Fourier-transform mid-infrared (FT-MIR) spectroscopy is widely used for dairy analysis, but its application to buffalo milk, with larger fat globules, remains understudied. The ultimate goal of this study is to develop machine learning models based on FT-MIR spectroscopy for predicting fatty acids in buffalo milk and to assess the accuracy of commercial milk analyzers. This research provides a convenient, fast, and environmentally friendly method for detecting the fatty acid composition in buffalo milk. RESULTS: We employed six machine learning algorithms to establish a detection model for 34 fatty acids in buffalo milk. The predictive models demonstrated robust capabilities for high-content fatty acids [C14:0, C15:0, C16:0, C17:0, C18:0, C18:1, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA)], with errors within a 15% range. Traditional FT6000 detection methods exhibited limitations in measuring SFAs and polyunsaturated fatty acids (PUFA). Implementing a mean difference correction of 0.21 for MUFAs and applying regression equations (SFA × 1.0639 + 0.0705; PUFA × 0.5472 + 0.0047) significantly improved measurement accuracy. CONCLUSION: This study successfully developed a predictive model for fatty acids in Mediterranean buffalo milk based on FT-MIR spectroscopy. Additionally, a correction was applied to the existing measurement device, FT6000, enabling more accurate measurements of fatty acids in buffalo milk. The findings have practical implications for the food industry, offering a faster and more reliable approach to assess and monitor fatty acid composition in buffalo milk, potentially influencing product development and quality control processes. © 2024 Society of Chemical Industry.

GSK2795039 prevents RIP1-RIP3-MLKL-mediated cardiomyocyte necroptosis in doxorubicin-induced heart failure through inhibition of NADPH oxidase-derived oxidative stress.

Doxorubicin (DOX), which is widely used for the treatment of cancer, induces cardiomyopathy associated with NADPH oxidase-derived reactive oxygen species. GSK2795039 is a novel small molecular NADPH oxidase 2 (Nox2) inhibitor. In this study, we investigated whether GSK2795039 prevents receptor-interacting protein kinase 1 (RIP1)-RIP3-mixed lineage kinase domain-like protein (MLKL)-mediated cardiomyocyte necroptosis in DOX-induced heart failure through NADPH oxidase inhibition. Eight-week old mice were randomly divided into 4 groups: control, GSK2795039, DOX and DOX plus GSK2795039. H9C2 cardiomyocytes were treated with DOX and GSK2795039. In DOX-treated mice, the survival rate was reduced, left ventricular (LV) end-systolic dimension was increased and LV fractional shortening was decreased, and these alterations were attenuated by the GSK2795039 treatment. GSK2795039 inhibited not only myocardial NADPH oxidase subunit gp91phox (Nox2) protein, but also p22phox, p47phox and p67phox proteins and prevented oxidative stress 8-hydroxy-2'-deoxyguanosine levels in DOX-treated mice. RIP3 protein and phosphorylated RIP1 (p-RIP1), p-RIP3 and p-MLKL proteins, reflective of their respective kinase activities, markers of necroptosis, were markedly increased in DOX-treated mice, and the increases were prevented by GSK2795039. GSK2795039 prevented the increases in serum lactate dehydrogenase and myocardial fibrosis in DOX-treated mice. Similarly, in DOX-treated cardiomyocytes, GSK2795039 improved cell viability, attenuated apoptosis and necrosis and prevented the increases in p-RIP1, p-RIP3 and p-MLKL expression. In conclusion, GSK2795039 prevents RIP1-RIP3-MLKL-mediated cardiomyocyte necroptosis through inhibition of NADPH oxidase-derived oxidative stress, leading to the improvement of myocardial remodeling and function in DOX-induced heart failure. These findings suggest that GSK2795039 may have implications for the treatment of DOX-induced cardiomyopathy.

Comparative analyses of copy number variations between swamp buffaloes and river buffaloes.

As an important source of genomic variation, copy number variation (CNV) contributes to environmental adaptation in worldwide buffaloes. Despite this importance, CNV divergence between swamp buffaloes and river buffaloes has not been studied previously. Here, we report 21 152 CNV regions (CNVRs) in 141 buffaloes of 20 breeds detected through multiple CNV calling strategies. Only 248 CNVRs were shared between river buffalo and swamp buffalo, reflecting great variation of CNVRs between the two subspecies. Population structure analysis based on CNVs successfully separated the two buffalo subspecies. We further assessed CNV divergence by calculating FST for genome-wide CNVs. Totally, we identified 110 significantly divergent CNV segments and 44 putatively selected genes between river buffaloes and swamp buffaloes. In particular, LALBA, a key gene controlling milk production in cattle, presented a highly differentiated CNV in the promoter region, which makes it a strong functional candidate gene for differences between swamp buffaloes and river buffaloes in traits related to milk production. Our study provides useful information of CNVs in buffaloes, which may help explain the genetic differences between the two subspecies.

Evolutionary analysis of buffalo sterol regulatory element-binding factor (SREBF) family genes and their affection on milk traits.

The sterol regulatory element-binding factor (SREBF) genes are a vital group of proteins binding to the sterol regulatory element 1 (SRE-1) regulating the synthesis of fatty acid. Two potential candidate genes (SREBF1 and SREBF2) have been identified as affecting milk traits. This study aims to identify the SREBF family of genes and find candidate markers or SREBF genes influencing lactation production in buffalo. A genome-wide study was performed and identified seven SREBF genes randomly distributed on 7 chromosomes and 24 protein isoforms in buffalos. The SREBF family of genes were also characterized in cattle, goat, sheep and horse, and using these all-protein sequences, a phylogenetic tree was built. The SREBF family genes were homologous between each other in the five livestock. Eight single nucleotide polymorphisms (SNPs) within or near the SREBF genes in the buffalo genome were identified and at least one milk production trait was associated with three of the SNP. The expression of SREBF genes at different lactation stages in buffalo and cattle from published data were compared and the SREBF genes retained a high expression throughout lactation with the trend being the same for buffalo and cattle. These results provide valuable information for clarifying the evolutionary relationship of the SREBF family genes and determining the role of SREBF genes in the regulation of milk production in buffalo.

Lactational exposure to Deoxynivalenol causes mammary gland injury via inducing inflammatory response and impairing blood-milk barrier integrity in mice.

Lactation is a unique physiological process to produce and secrete milk. Deoxynivalenol (DON) exposure during lactation has been demonstrated to affect adversely the growth development of offspring. However, the effects and potential mechanism of DON on maternal mammary glands remain largely unknown. In this study, we found the length and area of mammary glands were significantly reduced after DON exposure on lactation day (LD) 7 and LD 21. RNA-seq analysis results showed that the differentially expressed genes (DEGs) were significantly enriched in acute inflammatory response and HIF-1 signaling pathway, which led to an increase of myeloperoxidase activity and inflammatory cytokines. Furthermore, lactational DON exposure increased blood-milk barrier permeability by reducing the expression of ZO-1 and Occludin, promoted cell apoptosis by upregulating the expression of Bax and cleaved Caspase-3 and downregulating the expression of Bcl-2 and PCNA. Additionally, lactational DON exposure significantly decreased serum concentration of prolactin, estrogen, and progesterone. All these alterations eventually resulted in a decrease of ß-casein expression on LD 7 and LD 21. In summary, our findings indicated that lactational exposure to DON caused lactation-related hormone disorder and mammary gland injury induced by inflammatory response and blood-milk barrier integrity impairment, ultimately resulting in lower production of ß-casein.

Novel Insight into the Role of Squalene Epoxidase (SQLE) Gene in Determining Milk Production Traits in Buffalo.

Understanding the genetic mechanisms underlying milk production traits contribute to improving the production potential of dairy animals. Squalene epoxidase (SQLE) is one of the rate-limiting enzymes for cholesterol biosynthesis and was highly expressed in the buffalo mammary. The objectives of the present study were to detect the polymorphisms within SQLE in buffalo, the genetic effects of these mutations on milk production traits, and to understand the gene regulatory effects on buffalo mammary epithelial cells (BuMECs). A total of five SNPs were identified by sequencing, g.18858G > A loci were significantly associated with fat yield, and g.22834C > T loci were significantly associated with peak milk yield, milk yield, fat yield, and protein yield. Notably, linkage disequilibrium analysis indicated that 2 SNPs (g.18858G > A and g.22834C > T) formed one haplotype block, which was found to be significantly associated with milk fat yield, fat percentage, and protein yield. Furthermore, expression of SQLE was measured in different tissues of buffalo and was found to be higher in the mammary. Knockdown of SQLE gene expression significantly affected the growth of BuMECs, including proliferation, cell cycle, and apoptosis, and significantly downregulated the expression of related genes MYC, PCNA, and P21. In addition, knockdown of the SQLE gene significantly reduces triglyceride concentrations and the signal intensity of oil red O staining. In addition, silencing of SQLE was also found to regulate the synthesis and secretion of ß-casein and κ-casein negatively. Furthermore, SQLE knockdown is accompanied by the downregulation of critical genes (RPS6KB1, JAK2, eIF4E, and SREBP1) related to milk fat and protein synthesis. The current study showed the potential of the SQLE gene as a candidate for buffalo milk production traits. It provides a new understanding of the physiological mechanisms underlying buffalo milk production regulation.

"Three-in-One" Structural-Building-Mode-Based Ti16-Type Titanium Oxo Cluster Entirely Protected by the Ligands Benzoate and Salicylhydroxamate.

Titanium oxo clusters (TOCs) with accurate molecular structures have potential applications in photocatalysis, such as photocatalytic degradation, hydrogen production, and water oxidation. The hydrolytic stability and light absorption ability of TOCs have important impacts on photocatalysis, where the selection of peripheral organic ligands plays a significant role. In this regard, salicylhydroxamic acid (abbreviated as H3L) attracts our attention, acting as a ligand for its multidentate and dye-functional features, which can increase the hydrolytic stability and broaden light absorption for TOCs. Herein, two TOCs were solvothermally synthesized and structurally characterized using H3L, formulated as [Ti8(µ2-O)2(µ3-O)2(OiPr)12(L)4]·2CH3CN (1) and [Ti16(µ2-O)10(µ3-O)4(PhCOO)14(L)6(HL)2]·4CH3CN·2iPrOH (2). Complex 2 was obtained by adding excessive benzoic acid over the reaction system of 1, resulting in enhanced hydrolytic stability via the replacement of all alkoxy ligands by multidentate ligands for protection. Interestingly, for the first time, the "three-in-one" structural building mode with {Ti6} + {Ti4} + {Ti6} by the common subunits in 2 was observed among all reported TOCs. Moreover, complex 2 can strongly absorb visible light reaching up to 700 nm and exhibit obvious activity for the photodegradation of methyl orange.

Enhanced oxidative stress mediates pathological autophagy and necroptosis in cardiac myocytes in pressure overload induced heart failure in rats.

In cardiac myocytes in vitro, hydrogen peroxide induces autophagic cell death and necroptosis. Oxidative stress, myocyte autophagy and necroptosis coexist in heart failure (HF). In this study, we tested the hypothesis that excessive oxidative stress mediates pathological autophagy and necroptosis in myocytes in pressure overload-induced HF. HF was produced by chronic pressure overload induced by abdominal aortic constriction (AAC) in rats. Rats with AAC or sham operation were randomised to orally receive an antioxidant N-acetylcysteine (NAC) or placebo for 4 weeks. Echocardiography was performed for the assessments of left ventricular (LV) structure and function. AAC rats exhibited decreased LV fractional shortening (FS) at 4 weeks after surgery. NAC treatment attenuated decreased LV FS in AAC rats. In AAC rats, myocardial level of 8-hydroxydeoxyguanosine assessed by immunohistochemical staining, indicative of oxidative stress, was increased, LC3 II protein, a marker of autophagy, Beclin1 protein and Atg4b, Atg5, Atg7 and Atg12 mRNA expression were markedly increased, RIP1, RIP3 and MLKL expression, indicative of necroptosis, was increased, and all of the alterations in AAC rats were prevented by the NAC treatment. NAC treatment also attenuated myocyte cross-sectional area and myocardial fibrosis in AAC rats. In conclusion, NAC treatment prevented the increases in oxidative stress, myocyte autophagy and necroptosis and the decrease in LV systolic function in pressure overload-induced HF. These findings suggest that enhanced oxidative stress mediates pathological autophagy and necroptosis in myocytes, leading to LV systolic dysfunction, and antioxidants may be of value to prevent HF through the inhibition of excessive autophagy and necroptosis.

Characterization of extrachromosomal circular DNA in cattle using 676 whole genome sequencing datasets.

Extrachromosomal circular DNA (eccDNA) is an important fraction of the genome. Recent studies proved that eccDNA plays important roles in genetic variation, aging and environmental adaptation, which have drawn wide attention. However, the characteristics of eccDNA in cattle remain unclear. Here, we studied eccDNAs from 676 cattle of 58 breeds using whole genome sequencing datasets. In total, 47 355 high-confidence eccDNAs were identified and covered 4.6% of the cattle autosomes in length. Similarly to other species, the cattle eccDNA preferentially located in the genic and repeat sequences. Cattle eccDNAs contained complete sequences of 661 genes, which were significantly (p < 0.05) enriched in immunity-related functions. The eccDNA was further proved to have inverted repeats on the boundaries, which contained a high proportion of A/T and ranged from 4 to 17 bp. Interestingly, we successfully separated animals according to their geographical distributions and their tissues where DNA was isolated. This implied possible roles for eccDNA in cattle selection and tissue development. Our study supplies basic knowledges on eccDNAs in cattle, which will promote understanding of extrachromosomal DNA.

Transcriptome analysis of Macrobrachium rosenbergii: Identification of precocious puberty and slow-growing information.

Macrobrachium rosenbergii is an important economic aquatic animal and has been cultivated worldwide. However, it has suffered a disease of precocious puberty and growth retardation. This disease was also called iron prawn syndrome (IPS) in recent years. However, the cause of this disease has thus far remained a mystery . The present work utilized transcriptome sequencing technology to acquire gene expression information of gonads and to find the differentially expressed genes(DEGs) between diseased and normal male prawn. Finally, 426 significantly expressed genes were identified(p less than 0.01, |log2FC|≥1), of which 171 genes were up-regulated and 255 were down-regulated. Furthermore, DEGs were annotated to 36 GO terms and 202 KEGG pathways. Enrichment analysis of DEGs resulted in 10 significantly enriched GO terms and a total of 12 significantly enriched KEGG pathways. Analysis of the transcriptome sequences and DEGs identified several unigenes and pathways involved in precocious puberty and growth retardation. Quantitative PCR was performed to validate accuracy of the RNA-seq and the expression level of 10 genes, calculated by two analysis method, was mostly consistent. This is the first time to report precocious puberty and growth retardation male M. rosenbergii by transcriptome sequencing. The data presented here reveals key insights into the genetic markers of precocious puberty and growth retardation of male M. rosenbergii.

Novel functional mutation of the PDIA3 gene affects milk composition traits in Chinese Holstein cattle.

Protein disulfide isomerase family A member 3 (PDIA3) is a multifunctional protein, and it plays a vital role in modulating various cell biological functions under physiological and pathological conditions. Our previous study on Mediterranean buffalo demonstrated that PDIA3 is a potential candidate gene associated with milk yield based on genome-wide association study analysis. However, the genetic effects of the PDIA3 gene on milk performance in dairy cattle and the corresponding mechanism have not been documented. This study aims to explore the genetic effects of PDIA3 polymorphisms on milk production traits in 362 Chinese Holstein cattle. The results showed that 4 SNPs were identified from the 5' untranslated region of the PDIA3 gene in the studied population, of which 2 SNPs (g.-1713 C>T and g.-934 G>A) were confirmed to be significantly associated with milk protein percentage, whereas g.-434 C>T was significantly associated with milk fat percentage. Notably, linkage disequilibrium analysis indicated that 3 SNPs (g.-1713 C>T, g.-934 G>A, and g.-695 A>C) formed one haplotype block, which was found to be significantly associated with milk protein percentage. The luciferase assay demonstrated that allele C of g.-434 C>T exhibited a higher promotor activity compared with allele T, suggesting that g.-434 C>T might be a potential functional mutation affecting PDIA3 expression. Furthermore, overexpression of the PDIA3 gene was found to induce higher levels of triglyceride and BODIPY fluorescence intensity. In addition, PDIA3 overexpression was also found to positively regulate the synthesis and secretion of α-casein, ß-casein, and κ-casein, whereas knockdown of this gene showed the opposite effects. In summary, our findings revealed significant genetic effects of PDIA3 on milk composition traits, and the identified SNP and the haplotype block might be used as genetic markers for dairy cow selected breeding.

Deoxynivalenol exposure inhibits biosynthesis of milk fat and protein by impairing tight junction in bovine mammary epithelial cells.

Deoxynivalenol (DON) is one of the most common feed contaminants, and it poses a serious threat to the health of dairy cows. The existing studies of biological toxicity of DON mainly focus on the proliferation, oxidative stress, and inflammation in bovine mammary epithelial cells, while its toxicity on the biosynthesis of milk components has not been well documented. Hence, we investigated the toxic effects and the underlying mechanism of DON on the bovine mammary alveolar cells (MAC-T). Our results showed that exposure to various concentrations of DON significantly inhibited cell proliferation, induced apoptosis, and altered the cell morphology which was manifested by cell distortion and shrinkage. Moreover, the transepithelial electrical resistance (TEER) values of MAC-T cells exposed to DON were gradually decreased in a time- and concentration- dependent manner, but lactate dehydrogenase (LDH) leakage was significantly increased with the maximum increase of 2.4-fold, indicating the cell membrane and tight junctions were damaged by DON. Importantly, DON significantly reduced the synthesis of ß-casein and lipid droplets, along with the significantly decreases of phospho-mTOR, phospho-4EBP1, phospho-JAK2, and phospho-STAT5. Gene expression profiles showed that the expressions of several genes related to lipid synthesis and metabolism were changed, including acyl-CoA synthetase short-chain family member 2 (ACSS2), fatty acid binding protein 3 (FABP3), 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1), and insulin-induced gene 1 (INSIG1). GO and KEGG enrichment analyses revealed that the differentially expressed genes (DEGs) were significantly enriched in ribosome, glutathione metabolism, and lipid biosynthetic process, which play important roles in the toxicological process induced by DON. Taken together, DON affects the proliferation and functional differentiation of MAC-T cells, which might be related to the cell junction disruption and morphological alteration. Our data provide new insights into functional differentiation and transcriptomic alterations of MAC-T cells after DON exposure, which contributes to a comprehensive understanding of DON-induced toxicity mechanism.

Melatonin Promotes Antler Growth by Accelerating MT1-Mediated Mesenchymal Cell Differentiation and Inhibiting VEGF-Induced Degeneration of Chondrocytes.

The sika deer is one type of seasonal breeding animal, and the growth of its antler is affected by light signals. Melatonin (MLT) is a neuroendocrine hormone synthesized by the pineal gland and plays an important role in controlling the circadian rhythm. Although the MLT/MT1 (melatonin 1A receptor) signal has been identified during antler development, its physiological function remains almost unknown. The role of MLT on antler growth in vivo and in vitro is discussed in this paper. In vivo, MLT implantation was found to significantly increase the weight of antlers. The relative growth rate of antlers showed a remarkable increased trend as well. In vitro, the experiment showed MLT accelerated antler mesenchymal cell differentiation. Further, results revealed that MLT regulated the expression of Collage type II (Col2a) through the MT1 binding mediated transcription of Yes-associated protein 1 (YAP1) in antler mesenchymal cells. In addition, treatment with vascular endothelial growth factor (VEGF) promoted chondrocytes degeneration by downregulating the expression of Col2a and Sox9 (SRY-Box Transcription Factor 9). MLT effectively inhibited VEGF-induced degeneration of antler chondrocytes by inhibiting the Signal transducers and activators of transcription 5/Interleukin-6 (STAT5/IL-6) pathway and activating the AKT/CREB (Cyclin AMP response-element binding protein) pathway dependent on Sox9 expression. Together, our results indicate that MLT plays a vital role in the development of antler cartilage.

PRDX2 Knockdown Inhibits Extracellular Matrix Synthesis of Chondrocytes by Inhibiting Wnt5a/YAP1/CTGF and Activating IL-6/JAK2/STAT3 Pathways in Deer Antler.

Although peroxiredoxin 2 (PRDX2) plays a vital role in relieving oxidative stress, its physiological function in cartilage development remains almost unknown. In this study, we found that the expression of PRDX2 significantly increased in the chondrocytes compared with pre-chondrocytes. PRDX2 knockdown significantly decreased the expression of extracellular matrix (ECM) protein (Col2a and Aggrecan), which led to blocked cartilage formation. Moreover, PRDX2 knockdown also inhibited the expression of connective tissue growth factor (CTGF). CTGF is an important growth factor that regulates synthesis of ECM proteins. We explored the possible regulatory mechanism by which PRDX2 regulated the expression of CTGF. Our results demonstrated that PRDX2 knockdown downregulated the expression of CTGF by inhibiting Wnt5a/Yes-associated protein 1 (YAP1) pathway. In addition, PRDX2 knockdown promoted the expression of interleukin 6 (IL-6), indicating PRDX2 expression had an anti-inflammatory function during antler growth. Mechanistically, PRDX2 knockdown promoted cartilage matrix degradation by activating the IL-6-mediated Janus Kinase 2/Signal Transducer and Activator of Transcription 3 (JAK2/STAT3) signaling pathway. These results reveal that PRDX2 is a potential regulator that promotes cartilage extracellular matrix synthesis.