A spatiotemporal atlas of organogenesis in the development of orchid flowers.

Development of floral organs exhibits complex molecular mechanisms involving the co-regulation of many genes specialized and precisely functioning in various tissues and developing stages. Advance in spatial transcriptome technologies allows for quantitative measurement of spatially localized gene abundance making it possible to bridge complex scenario of flower organogenesis with genome-wide molecular phenotypes. Here, we apply the 10× Visium technology in the study of the formation of floral organs through development in an orchid plant, Phalaenopsis Big Chili. Cell-types of early floral development including inflorescence meristems, primordia of floral organs and identity determined tissues, are recognized based on spatial expression distribution of thousands of genes in high resolution. In addition, meristematic cells on the basal position of floral organs are found to continuously function in multiple developmental stages after organ initiation. Particularly, the development of anther, which primordium starts from a single spot to multiple differentiated cell-types in later stages including pollinium and other vegetative tissues, is revealed by well-known MADS-box genes and many other downstream regulators. The spatial transcriptome analyses provide comprehensive information of gene activity for understanding the molecular architecture of flower organogenesis and for future genomic and genetic studies of specific cell-types.

Deciphering the impacts of chromium contamination on soil bacterial communities: A comparative analysis across various soil types.

Addressing the widespread concern of chromium (Cr) pollution, this study investigated its impacts on bacterial communities across eight soil types, alongside the potential Cr transformation-related genes. Utilizing real-time PCR, 16S rRNA gene sequencing and gene prediction, we revealed shifts in bacterial community structure and function at three Cr exposure levels. Our results showed that the bacterial abundance in all eight soil types was influenced by Cr to varying extents, with yellow‒brown soil being the most sensitive. The bacterial community composition of different soil types exhibited diverse responses to Cr, with only the relative abundance of Proteobacteria decreasing with increasing Cr concentration across all soil types. Beta diversity analysis revealed that while Cr concentration impacted the assembly process of bacterial communities to a certain extent, the influence on the compositional structure of bacterial communities was primarily driven by soil type rather than Cr concentration. The study also identified biomarkers for each soil type under three Cr levels, offering a basis for monitoring changes in Cr pollution. By predicting crucial functional genes related to Cr transformation, it was observed that the relative abundance of chrA (chromate transporter) in yellow‒brown soil significantly exceeded that in all other soil types, suggesting its potential for Cr adaptation. The study also revealed correlations among soil physicochemical properties, Cr concentration, and these functional genes, providing a foundation for future research aimed at more precise functional analysis and the development of effective soil remediation strategies.

Evaluation of BPA effects on autophagy in Neuro-2a cells.

Bisphenol A (BPA), which is used for the industrial production of polycarbonate plastics and epoxy resins, is found in many commercially available products. Plasticizer BPA produces chemical substances worldwide, and knowledge of its effects on humans and animals is increasing. In the present work, the morphology of cells was observed by optical microscopy and phalloidin staining to evaluate the toxic effect of BPA on Neuro-2a cells. Autophagy has an important role in the regulation of cell metabolism. To study the effect of BPA on the autophagy in Neuro-2a cells, the expression distribution of LC3 was detected by immunofluorescence, and the expression levels of p62 and Beclin1 were determined using western blot and quantitative real-time PCR (qRT-PCR), respectively. Optical microscopy and phalloidin staining revealed that the cells became rounded and small and that the dendritic spine of the cells were reduced at high BPA doses. Immunofluorescence analysis demonstrated that the expression of LC3 fluorescence intensity was weak at increasing BPA concentrations. Western blot results showed that the relative expression of protein p62 increased significantly and that the relative expression levels of the Beclin1 and the LC3 proteins significantly decreased with increasing BPA concentration. qRT-PCR results showed that the relative expression level of autophagy-related p62 mRNA increased significantly and that the relative expression level of Beclin1 mRNA decreased significantly with increasing BPA concentration. The above results indicated that BPA treatment exerted dose-dependent toxic effects on Neuro-2a cells, and BPA inhibited the autophagy level of Neuro-2a cells, thereby providing a new perspective in studying the toxic effect of BPA on Neuro-2a cells.

The construction and analysis of ceRNA network and patterns of immune infiltration in lung adenocarcinoma.

BACKGROUND: Competitive Endogenous RNA (ceRNA) may be closely associated with tumor progression. However, studies on ceRNAs and immune cells in LUAD are scarce. METHOD: The profiles of gene expression and clinical data of LUAD patients were extracted from the TCGA database. Bioinformatics methods were used to evaluate differentially-expressed genes (DEGs) and to form a ceRNA network. Preliminary verification of clinical specimens was utilized to detect the expressions of key biomarkers at the tissues. Cox and Lasso regressions were used to identify key genes, and prognosis prediction nomograms were formed. The mRNA levels of 9 genes in the risk score model in independent clinical LUAD samples were detected by qRT-PCR. The interconnection between the risk of cancer and immune cells was evaluated using the CIBERSORT algorithm, while the conformation of notable tumor-infiltrating immune cells (TIICs) in the LUAD tissues of the high and low risk groups was assessed using the RNA transcript subgroup in order to identify tissue types. Finally, co-expression study was used to examine the interconnection between the key genes in the ceRNA networks and the immune cells. RESULT: A ceRNA network of 115 RNAs was established, and nine key genes were identified to construct a Cox proportional-hazard model and create a prognostic nomogram. This risk-assessment model might serve as an independent factor to forecast the prognosis of LUAD, and it was consistent with the preliminary verification of clinical specimens. Survival analysis of clinical samples further validated the potential value of high risk groups in predicting LUAD prognosis. Five immune cells were identified with significant differences in the LUAD tissues of the high and low risk groups. Besides, two pairs of biomarkers associated with the growth of LUAD were found, i.e., E2F7 and macrophage M1 (R = 0.419, p = 1.4e- 08) and DBF4 and macrophage M1 (R = 0.282, p < 2.2 e- 16). CONCLUSION: This study identified several important ceRNAs, i.e. (E2F7 and BNF4) and TIICs (macrophage M1), which might be related to the development and prognosis of LUAD. The established risk-assessment model might be a potential tool in predicting LUAD of prognosis.

Prediction of Stable Ground-State Binary Sodium-Potassium Interalkalis under High Pressures.

The complex structures and electronic properties of alkali metals and their alloys provide a natural laboratory for studying the interelectronic interactions of metals under compression. A recent theoretical study (J. Phys. Chem. Lett. 2019, 10, 3006) predicted an interesting pressure-induced decomposition-recombination behavior of the Na2K compound over a pressure range of 10-500 GPa. However, a subsequent experiment (Phys. Rev. B 2020, 101, 224108) reported the formation of NaK rather than Na2K at pressures above 5.9 GPa. To address this discordance, we study the chemical stability of different stoichiometries of NaxK (x = 1/4, 1/3, 1/2, 2/3, 3/4, 4/3, 3/2, and 1-4) by an effective structure searching method combined with first-principles calculations. Na2K is calculated to be unstable at 5-35 GPa due to the decomposition reaction Na2K → NaK + Na, coinciding well with the experiment. NaK undergoes a combination-decomposition-recombination process accompanied by an opposite charge-transfer behavior between Na and K with pressure. Besides NaK, two hitherto unknown compounds NaK3 and Na3K2 are uncovered. NaK3 is a typical metallic alloy, while Na3K2 is an electride with strong interstitial electron localization.

Ferroptosis-related genes for predicting prognosis of patients with laryngeal squamous cell carcinoma.

BACKGROUND: Previous studies reported that ferroptosis-related genes can regulate the process of tumor cell changes by regulating iron metabolism. However, the prognostic value of ferroptosis-related genes in LC remains to be further elucidated. METHODS: Ferroptosis-related gene expression profiles of coexisting ferroptosis-related genes were extracted from both cohorts (TCGA and GSE27020) for eligible analysis. LASSO Cox regression was utilized to build an optimum ferroptosis-related prognostic model. Kaplan-Meier curve was performed by log-rank test, and time-dependent ROC curve was constructed to evaluate the predictive power of this signature in both cohorts. GO and KEGG enrichment analysis was used to investigate the potential mechanism of differential enrichment signal pathways. RESULTS: 112 LC patients from the TCGA cohort and 108 LC patients with clinical information from the GEO cohorts were eventually included in the study. Three ferroptosis-related genes were identified as an independent risk factor to establish the prognostic risk score. Kaplan-Meier curve represented that patients with high-risk group favors with worse OS than their low-risk group (P = 0.04). The good performance of the gene signature for predicting OS was evaluated by area under the curve (AUC) of time-dependent ROC curves achieved 0.74 at 3 years, and 0.70 at 5 years. Similar performance has been proved in the external validation cohort. GO and KEGG enrichment analysis have been performed to explore the signaling pathways and underlying mechanisms were significantly active in LC patients. CONCLUSION: In summary, our study developed a ferroptosis-related model that could be an effective biomarker to predict the prognosis of laryngeal cancer.

Enabling Molecular Gapping and Bridging on a Biosensing Surface via Electrochemical Cross-Linking and Cleavage.

Protein detection in complicated biological samples requires robust design and a rigorous rinsing process. Many recently developed artificial targeting probes, however, often do not possess antibody-like binding strength that enables them to endure harsh biosensing conditions, and the classic 2-to-1 sandwich binding pattern is unavailable for many targets, often necessitating a complicated indirect signal conversion mechanism. Here, an attempt is made to provide innovative "covalent" solutions to such problems by employing peptide reactivity to form a covalent and robust biosensing structure upon target binding. Both the cross-coupling and cleavage of peptide chains are employed to achieve the classic 2-to-1 binding when only one targeting probe is available. Specifically, a targeting probe against the protein and a signaling probe are coimmobilized onto the sensing interface. The ratio between the two probes and their surface density is modulated so that direct cross-linking between the two immobilized probes is suppressed by the average distance between two such probes. Upon protein binding, the protein molecule may bridge that gap by itself. The signaling probe can carry any motif of signal amplification. And here a Cu-ion-complexed motif, which can exhibit peroxidase-like activity upon electrochemical agitation, is employed multipurposely as the catalyst for cross-linking, cleavage, and signal amplification. Three nonhomologous target proteins can be sensitively quantified in serum-spiked samples and clinical sample detection of one of them is also successful; these results suggest the potential of the proposed method in future clinical applications.

Correction to: Induced cultivation pattern enhanced the phycoerythrin production in red alga Porphyridium purpureum.

The original version of the article unfortunately contained an error in Microalgae strain and culture medium section. Below is the corrected version.

Induced cultivation pattern enhanced the phycoerythrin production in red alga Porphyridium purpureum.

Porphyridium purpureum is a rich source for producing phycoerythrin (PE); however, the PE content is greatly affected by culture conditions. Researchers have aimed to optimize the cultivation of P. purpureum for accumulation of PE. When traditional optimized culture conditions were used to cultivate P. purpureum, high PE contents were not usually achieved. In this study, an induced cultivation pattern was applied to P. purpureum for PE biosynthesis (i.e., an incremental approach by altering temperatures, light intensities, and nitrate concentrations). Results revealed that the induced pattern greatly improved the PE biosynthesis. The optimized PE content of 229 mg/L was achieved on the 12th cultivation day, which was a maximum PE content within one cultivation period and accounted for approximately 3.05% of the dry biomass. The induced cultivation pattern was highly suitable for PE synthesis in P. purpureum, which provided an important reference value to the large-scale production of PE.

[Three-dimensional reconstruction of carp brain tissue and brain electrodes for biological control].

In order to accurately implant the brain electrodes of carp robot for positioning and navigation, the three-dimensional model of brain structure and brain electrodes is to be proposed in the study. In this study, the tungsten electrodes were implanted into the cerebellum of a carp with the aid of brain stereotaxic instrument. The brain motor areas were found and their three-dimensional coordinate values were obtained by the aquatic electricity stimulation experiments and the underwater control experiments. The carp brain and the brain electrodes were imaged by 3.0 T magnetic resonance imaging instrument, and the three-dimensional reconstruction of carp brain and brain electrodes was carried out by the 3D-DOCTOR software and the Mimics software. The results showed that the brain motor areas and their coordinate values were accurate. The relative spatial position relationships between brain electrodes and brain tissue, brain tissue and skull surface could be observed by the three-dimensional reconstruction map of brain tissue and brain electrodes which reconstructed the three-dimensional structure of brain. The anatomical position of the three-dimensional reconstructed brain tissue in magnetic resonance image and the relationship between brain tissue and skull surface could be observed through the three-dimensional reconstruction comprehensive display map of brain tissue. The three-dimensional reconstruction model in this study can provide a navigation tool for brain electrodes implantation.

Evaluation of the MiSeq FGx system for use in forensic casework.

Capillary electrophoresis (CE) is widely used in forensic genetics to study short tandem repeats (STRs). Recently, next-generation sequencing (NGS) platforms have facilitated the development of new strategies for forensic DNA typing. Several studies have shown that NGS successfully analyzes challenging samples. However, because NGS is complicated and time-consuming, it remains unclear whether NGS platforms offer significant advantages over CE for all forensic cases. Here, the MiSeq FGx system was used to test some cases that had previously been analyzed using CE. These cases included paternity test cases in which some samples exhibited locus inconsistencies; samples with off-ladder (OL) alleles; samples with triallelic patterns; and samples with amelogenin test abnormalities. The results generated by MiSeq FGx were compared to those previously generated by CE. The MiSeq FGx and CE results were consistent with the exception of three samples, where inconsistencies were observed at the Penta D locus. For all three incongruent samples, the MiSeq FGx results were correct. Sequence analysis indicated that, in two cases, mismatches were due to undetected alleles rather than mutations. In two additional cases, mutation sources were identified, and in a fifth case, mutation step size was reconsidered. MiSeq FGx was used to identify OL alleles and samples with amelogenin test abnormalities. For cases where verification was required via CE analysis, the simultaneous NGS amplification of several types of multiple genetic markers improved testing efficiency. In addition, we identified additional sequence variants at autosomal, Y chromosomal, and X chromosomal STR loci in the Han Chinese population from northern China. Our results will be useful for future forensic analyses of STR genotypes in Chinese populations. It is likely that NGS would be more widely used in forensic genetics if costs and procedure complexity were reduced.

Arbuscular mycorrhizal fungi alleviate arsenic toxicity to Medicago sativa by influencing arsenic speciation and partitioning.

In a pot experiment, Medicago sativa inoculated with/without arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis were grown in four levels (0, 10, 25, and 75 mg/kg) of arsenic (As)-polluted soil to investigate the influences of AM symbiosis on plant As tolerance. The results showed that mycorrhizal inoculation significantly increased plant biomass, while As addition decreased mycorrhizal colonization and hyphal length density. Mycorrhizal inoculation dramatically improved plant phosphorus (P) nutrition, restricted As uptake and retained more As in roots by upregulating the expression of the AM-induced P transporter gene MsPT4 and the metallothionein gene MsMT2. High soil As content downregulated MsPT4 expression. Dimethylarsenic acid (DMA) was detected only in the shoots of mycorrhizal plants, indicating that AM fungi likely play an essential role in As detoxification by biological methylation. The present investigation allowed deeper insights into the As detoxification mechanisms of AM associations and demonstrated the important role of AM fungi in plant resistance under As-contaminated conditions.

[Research and application of magnetic resonance coordinate transformation method for brain control technology of carp robots].

To solve the problem of precise positioning of carp brain tissue coordinates, it is proposed in this paper for a method for transforming the coordinates of magnetic resonance imaging of carp brain tissue into the coordinates of electrode implantation using a brain stereotaxic apparatus. In this study, the 3.0T magnetic resonance imaging instrument was used to scan the carp brain. We independently established the three-dimensional positioning coordinate system of the brain, the three-dimensional coordinate assistance system of skull surface and the three-dimensional coordinate assistance system in brain tissue. After two coordinate transformations, the magnetic resonance image coordinates of the brain electrodes implantation sites were converted into the three-dimensional stereotactic coordinate system to guide the electrodes implantation. The experimental groups were divided into two groups, A and B. Group A was the group of magnetic resonance imaging apparatus combining with the brain stereotaxic apparatus, and group B was the group of brain atlas combining with the brain stereotaxic apparatus. Each group had 20 tails of carps ( n = 20). This two methods were used to implant the electrodes into the cerebellar motor area. The underwater experiments of the carp robots were carried out to test the two methods. The results showed that the accuracy of the implanted electrodes were 90% in group A and 60% in group B. The success rate of group A was significantly higher than that of group B ( P < 0.05). Therefore, the new method in this paper can accurately determine the coordinates of carp brain tissue.

miR-491 inhibits skeletal muscle differentiation through targeting myomaker.

The myogenesis of skeletal muscle has several stages, including satellite cell proliferation, differentiation, fusion and specific muscle formation. Recent studies have shown that myomaker, a muscle-specific transmembrane protein, was critical for myoblasts fusion. However, the regulatory mechanism of myomaker and its effects on myogenesis remain elusive. In this study, miR-491 was identified as a post-transcriptional regulator of myomaker, which binds specifically to its 3' untranslated region leading to its down-regulation. At the end of myotube differentiation, the expression levels of miR-491 increased drastically, while myomaker was significantly down-regulated, which indicated that miR-491 shut down the expression of myomaker. Functional studies showed that miR-491 overexpression suppressed muscle cell differentiation and adult muscle regeneration, while the inhibition of miR-491 promoted myotube differentiation. Taken together, our findings identified miR-491 as a novel negative regulator of myogenic differentiation through targeting myomaker.

Nanoaramid Dressed Latex Particles: The Direct Synthesis via Pickering Emulsion Polymerization.

The direct synthesis of polymer microspheres modified by aramid nanofibers (ANFs) is an interesting challenge. This work describes a simple aqueous process to prepare polystyrene (PS)/ANF composite microspheres, where the specific ANF network was "dressed" on PS. ANF was derived from the copolymerization of terephthaloyl chloride, p-phenylene diamine, and methoxypolyethylene glycol and could be dispersed in water stably. We applied the as-synthesized ANF as a Pickering emulsifier in the o/w emulsion of styrene monomer. Radical polymerization was subsequently initiated in the Pickering emulsion system. The combination of ANF with polymer spheres was revealed by scanning electron microscopy (SEM) and thermal gravity analysis. The role of ANF in the monomer emulsion as well as in the polymerization was studied through SEM, optical microscopy, optical stability analyzer, and pulse nuclear magnetic resonance combined with the polymerization kinetic analysis. Moreover, we investigated the effects of other synthesis parameters, such as monomer type, monomer content, pH value, and salt concentration.

Pseudonocardia profundimaris sp. nov., isolated from marine sediment.

A novel Gram-stain-positive, aerobic, non-motile actinobacterium, designated GY0556T, was isolated from deep-sea sediment collected from the western Pacific Ocean at a depth of 7118 m. Phylogenetic analysis based on 16S rRNA gene sequences revealed that this strain belongs to the genus Pseudonocardia, being most closely related to Pseudonocardia hydrocarbonoxydans IMSNU 22140T (97.6 % similarity), Pseudonocardia sulfidoxydans DSM 44248T (97.6 %) and Pseudonocardia alaniniphila Y-16303T (97.6 %); similarity to other type strains of the genus Pseudonocardia was less than 97.5 %. Strain GY0556T contained MK-8(H4) as the predominant menaquinone and iso-C16 : 0 and iso H-C16 : 1 as the major fatty acids. The polar lipids detected in strain GY0556T were phosphatidylcholine, phosphatidylinositol, one unknown glycolipid, one unknown phospholipid and two unknown lipids. The whole organism hydrolysates mainly consisted of meso-diaminopimelic acid, xylose, galactose and arabinose. The DNA G+C content of strain GY0556T was 76.9 mol%. The results of DNA-DNA hybridizations and phylogenetic analysis, together with the phenotypic and biochemical tests, allowed the differentiation of strain GY0556T from established members of the genus Pseudonocardia. Therefore, it is proposed that strain GY0556T represents a novel species of the genus Pseudonocardia, for which the name Pseudonocardia profundimaris sp. nov. is proposed. The type strain is GY0556T (=MCCC 1A10574T=KCTC 39641T).

Simulated microgravity disrupts intestinal homeostasis and increases colitis susceptibility.

The immune systems can be altered by spaceflight in many aspects, but microgravity-related mucosal immune changes and its clinical significance have not been well studied. The purpose of this study was to investigate whether simulated microgravity influences the intestinal homeostasis and increases the susceptibility to colon inflammation. The hindlimb unloading (HU) mouse model was used to simulate the microgravity condition. Three percent dextran sulfate sodium (DSS) was given to mice to induce colitis. Compared to ground control (Ctrl) mice, the HU ones revealed an impaired intestinal homeostasis and increased susceptibility to DSS-induced colitis. This includes an early-onset, 4-fold expansion of segmented filamentous bacteria (SFB), more than 2-fold decrease in regulatory T (Treg) cell numbers and IL-10 production, ∼2-fold increase in colonic IL-1ß expression, 2-fold increase in circulating neutrophils, and colonic neutrophil infiltration. The application of antibiotics ameliorated the Treg and IL-10 reductions but did not significantly dampen neutrophilia and elevated expression of colonic IL-1ß. These results indicate that the intestinal microflora and innate immune system both respond to simulated microgravity and together, contribute to the proinflammatory shift in the gut microenvironment. The data also emphasize the necessity for evaluating the susceptibility to inflammatory bowel diseases (IBDs) in distant space travels.

Nocardioides rotundus sp. nov., isolated from deep seawater.

A Gram-staining-positive, aerobic, coccoid-shaped, non-motile actinobacterium, designated strain GY0594T, was isolated from deep seawater of the western Pacific. Phylogenetic analyses based on 16S rRNA gene sequences showed that this strain was affiliated with the genus Nocardioides with low 16S rRNA gene sequence similarities ( ≤ 96.0 %) with members of the genus Nocardioides. Chemotaxonomic characterization of strain GYP0594T supported the result of the phylogenetic analysis. The diagnostic diamino acid in the cell-wall peptidoglycan was ll-2,6-diaminopimelic acid. The major menaquinone was MK-8(H4). The polar lipids detected were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unidentified lipid and six unidentified phospholipids. The major cellular fatty acids were iso-C16 : 0 and C18 : 1ω9c. The DNA G+C content of strain GY0594T was determined to be 71.2 mol%. However, strain GY0594T could be distinguished from closely related species by cell morphology, nitrate reduction, aesculin hydrolysis, activity of urease, cystine arylamidase, trypsin and acid phosphatase, assimilation of N-acetylglucosamine, maltose, adipic acid, malic acid and phenylacetate, and significant differences in the proportions of several fatty acids. In conclusion, based on the data presented, strain GY0594T should be placed in the genus Nocardioides as a representative of a novel species, for which the name Nocardioides rotundus sp. nov. is proposed. The type strain is GY0594T ( = MCCC 1A10561T = KCTC 39638T).

Amycolatopsis albispora sp. nov., isolated from deep-sea sediment.

A novel Gram-stain-positive, aerobic, non-motile actinobacterium, designated strain WP1T, was isolated from a deep-sea sediment sample collected from the Indian Ocean, and examined in a taxonomic study using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain WP1T formed a distinct phyletic lineage in the genus Amycolatopsis and was closely related to A. magusensis KT2025T (97.8 % 16S rRNA gene sequence similarity), A. palatopharyngis 1BDZT (97.3 %) and A. marinaMs392AT (97.2 %). The isolate grew at 4-45 °C, pH 5-11 and in the presence of 0-8 % (w/v) NaCl. The cell wall of the novel strain contained meso-diaminopimelic acid and arabinose and galactose as the diagnostic sugars. Major fatty acids identified were iso-C16 : 0, C17 : 1ω8c and C17 : 1ω6c. The predominant menaquinones were MK-9(H4) and MK-7. The polar lipids detected were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylmethylethanolamine, four unknown phospholipids and one unknown glycolipid. The genomic DNA G+C content was 72.2 mol%. Strain WP1T displayed low DNA-DNA reassociation with A. magusensis DSM 45510T (mean value 36.2 %), A. palatopharyngis JCM 12460T (31.5 %) and A. marina JCM 16121T (29.7 %). Based on the data reported here, strain WP1T represents a novel species within the genus Amycolatopsis, for which the name Amycolatopsis albisporasp. nov. is proposed. The type strain is WP1T (=KCTC 39642T=MCCC 1A10745T).

Skin proteomic screening and functional analysis of differential proteins associated with coat color in sheep (Ovis aries).

Objective: Coat color is an important characteristic and economic trait in domestic sheep. In this study, we explored the potential mechanisms and the signaling pathways involved in coat color regulation for sheep. Methods: Isobaric tags for relative and absolute quantification (iTRAQ) technology was used to catalog global protein expression profiles in skin of sheep with black versus white coat color. Immunofluorescence was used to observe the expression localization of differential protein. Western blot and quantitative real time polymerase chain reaction (qRT-PCR) were used to evaluate their role in the coat color formation of sheep. Results: A total of 136 differential proteins were obtained in different coat colors, including 101 up-regulated and 35 down-regulated. Pigmentation function entries were enriched through GO annotation. Tyrosine metabolism and platelet activation signaling pathway were extracted by KEGG analysis. APOA1 (Apolipoprotein A-1) and FGA (Fibrinogen alpha chain) were found to be critical differential proteins by the interaction of differential proteins in the direct-interaction network diagram. Strikingly, twenty candidate differential proteins were screened, from which ACTB (Beta-actin) protein showed higher expression in white sheep skin, while ALB (albumin), APOA1 MAOA (Amine oxidase) and FGA proteins showed higher expression in black sheep skin, which validated by immunofluorescence, western blot and qRT-PCR. Conclusion: Our studies identified several novel proteins that may involved in the coat color formation of sheep. The white and black sheep skin proteome profiles obtained provide a valuable resource for future research to understand the network of protein expression controlling skin physiology and melanogenesis in sheep.