Chemical composition and microbiota changes across musk secretion stages of forest musk deer.

Forest musk deer is the most important animal for natural musk production, and the musk composition changes periodically during musk secretion, accompanied by variation in the com-position of deer-symbiotic bacteria. GC-MS and 16S rRNA sequencing were conducted in this study, the dynamic changes to correlated chemical composition and the microbiota across musk secretion periods (prime musk secretion period, vigorous musk secretion period and late musk secretion period) were investigated by integrating its serum testosterone level in different mating states. Results showed that the testosterone level, musk composition and microbiota changed with annual cycle of musk secretion and affected by its mating state. Muscone and the testosterone level peaked at vigorous musk secretion period, and the microbiota of this stage was distinct from the other 2 periods. Actinobacteria, Firmicutes and Proteobacteria were dominant bacteria across musk secretion period. PICRUSt analysis demonstrated that bacteria were ubiquitous in musk pod and involved in the metabolism of antibiotics and terpenoids in musk. "Carbohydrates and amino acids," "fatty acids and CoA" and "secretion of metabolites" were enriched at 3 periods, respectively. Pseudomonas, Corynebacterium, Clostridium, Sulfuricurvum were potential biomarkers across musk secretion. This study provides a more comprehensive understanding of genetic mechanism during musk secretion, emphasizing the importance of Actinobacteria and Corynebacterium in the synthesis of muscone and etiocholanone during musk secretion, which required further validation.

IL6-STAT3-C/EBPß-IL6 positive feedback loop in tumor-associated macrophages promotes the EMT and metastasis of lung adenocarcinoma.

BACKGROUND: Lung cancer is one of the most common tumors in the world, and metastasis is one of the major causes of tumor-related death in lung cancer patients. Tumor-associated macrophages (TAMs) are a major component of the tumor microenvironment (TME) and are frequently associated with tumor metastasis in human cancers. However, the regulatory mechanisms of TAMs in lung cancer metastasis remain unclear. METHODS: Single-cell sequencing analysis of lung cancer and normal tissues from public databases and from 14 patients who underwent surgery at Zhongshan Hospital was performed. In vitro co-culture experiments were performed to evaluate the effects of TAMs on lung cancer migration and invasion. Changes in the expression of IL-6, STAT3, C/EBPΒ, and EMT pathway were verified using RT-qPCR, western blotting, and immunofluorescence. Dual luciferase reporter assays and ChIP were used to reveal potential regulatory sites on the transcription factor sets. In addition, the effects of TAMs on lung cancer progression and metastasis were confirmed by in vivo models. RESULTS: TAM infiltration is associated with tumor progression and poor prognosis. IL-6 secreted by TAMs can activate the JAK2/STAT3 pathway through autocrine secretion, and STAT3 acts as a transcription factor to activate the expression of C/EBPß, which further promotes the transcription and expression of IL-6, forming positive feedback loops for IL6-STAT3-C/EBPß-IL6 in TAMs. IL-6 secreted by TAMs promotes lung cancer progression and metastasis in vivo and in vitro by activating the EMT pathway, which can be attenuated by the use of JAK2/STAT3 pathway inhibitors or IL-6 monoclonal antibodies. CONCLUSIONS: Our data suggest that TAMs promote IL-6 expression by forming an IL6-STAT3-C/EBPß-IL6 positive feedback loop. Released IL-6 can induce the EMT pathway in lung cancer to enhance migration, invasion, and metastasis. The use of IL-6-neutralizing antibody can partially counteract the promotion of LUAD by TAMs. A novel mechanism of macrophage-promoted tumor progression was revealed, and the IL6-STAT3-C/EBPß-IL6 signaling cascade may be a potential therapeutic target against lung cancer.

Correlation Analysis between Muskrat (Ondatra zibethicus) Musk and Traditional Musk.

Muskrat musk is considered to be a potential substitute for traditional musk. However, little is known about the similarity between muskrat musk and musk, and whether it is related to muskrat age. In this study, muskrat musk (MR1, MR2, and MR3) were from 1, 2, and 3-year-old muskrats, respectively, and white musk (WM) and brown musk (BM) were picked from male forest musk deer. The results indicated that muskrat musk had higher similarity to WM than BM. Further research showed that RM3 had the highest matched degree with WM. By significantly different metabolite analysis, we found that 52 metabolites continue to increase from 1- to 3-year-old muskrats. In total, 7 and 15 metabolites were significantly decreased in RM1 vs. RM2 and RM2 vs. RM3, respectively. Meanwhile, 30 and 17 signaling pathways were observed from increased and decreased metabolites, respectively. The increased metabolites mainly entailed enrichment in amino acid biosynthesis and metabolism, steroid hormone biosynthesis, and fatty acid biosynthesis. In conclusion, muskrat musk from three-year-old muskrat is a relatively good substitute for white musk, and the result also implies that these biological processes of amino acid biosynthesis and metabolism, steroid hormone biosynthesis, and fatty acid biosynthesis are beneficial to the secretion of muskrat musk.

A Simple Method for the Synthesis of a Coral-like Boron Nitride Micro-/Nanostructure Catalyzed by Fe.

Catalyzed by Fe, novel a coral-like boron nitride (BN) micro-/nanostructure was synthesized from B2O3 by a ball milling and annealing process. Observations of the morphology of the product indicated that the coral-like BN micro-/nanostructure consists of a bamboo-shaped nanotube stem and dense h-BN nanoflakes growing outward on the surface of the nanotube. Experimental results showed that the morphology of the BN nanotube was greatly dependent on the anneal process parameters. With the annealing time increasing from 0.5 h to 4 h, the morphology developed from smooth BN nanotubes, with a diameter size of around 100 nm, to rough, coral-like boron nitride with a large diameter of 3.6 µm. The formation mechanism of this coral-like BN micro-/nanostructure is a two-stage growth process: bamboo-shaped BN nanotubes are first generated through a vapor-liquid-solid (VLS) mechanism and then nanoflakes grow surrounding the surface of the nanotube. Acid pickling and a hydrolysis process were carried out to remove Fe, iron nitrogen and unreacted B2O3 impurities.

Genomic And Tumor Microenvironment Differences Between Cell Cycle Progression Pathway Altered/Non-Altered Patients With Lung Adenocarcinoma.

Background: Identified as a hallmark of cancer, the dysregulated cell cycle progression plays an important role in the promotion and progression of lung adenocarcinoma (LUAD). However, the genomic and microenvironment differences between cell cycle progression pathway altered/non-altered LUAD patients remain to be elucidated. Materials and Methods: Data of this study were obtained from The Cancer Genome Atlas (TCGA), including simple nucleotide variation, copy number variation (CNV), RNA-seq gene expression, miRNA expression, survival, and clinical information. Besides, 34 LUAD samples from our institution were used as a validation cohort. Differentially expressed genes (DEGs), enrichment analysis, and immune cell infiltration were detected. At last, we built a LASSO-binary Logistic regression model to predict the cell-cycle-related gene mutation (CDKN2A, CCND1, CDK4, CCNE1, and RB1) in LUAD patients and further verified it in the samples from our institution. Results: Based on the cell cycle progression pathway status, the LUAD patients were divided into the mutation (n=322) and wild (n=46) groups. Compared to the wild group, the mutation group had a higher mutational load and CNV. Among the 16684 protein-coding genes analyzed, 302 were upregulated, and 354 were downregulated in the mutation group. Enrichment analysis indicated that these DEGs were closely related to metabolism items. After performing immune cell infiltration analysis of 22 immune cells, we found the proportion of 5 immune cells such as monocytes (P<0.01) and dendritic cells (P<0.01) were higher in the wild group. Finally, a cell-cycle-related 15-signature model was built by LASSO-Logistic regression analysis, which could predict the cell cycle progression pathway-related gene mutation (CDKN2A, CCND1, CDK4, CCNE1, and RB1) in LUAD patients. The validation cohorts showed the sensitivity and specificity of this model were 0.667 and 0.929, respectively. Conclusion: The genomic and microenvironment characteristics differed between the cell cycle progression pathway altered/non-altered patients with LUAD. Our findings may provide new insight into personalized treatment for LUAD patients.

Multi-Omics Analysis of Cancer Cell Lines with High/Low Ferroptosis Scores and Development of a Ferroptosis-Related Model for Multiple Cancer Types.

Background: Ferroptosis is a newly identified regulated cell death characterized by iron-dependent lipid peroxidation and subsequent membrane oxidative damage, which has been implicated in multiple types of cancers. The multi-omics differences between cancer cell lines with high/low ferroptosis scores remain to be elucidated. Methods and Materials: We used RNA-seq gene expression, gene mutation, miRNA expression, metabolites, copy number variation, and drug sensitivity data of cancer cell lines from DEPMAP to detect multi-omics differences associated with ferroptosis. Based on the gene expression data of cancer cell lines, we performed LASSO-Logistic regression analysis to build a ferroptosis-related model. Lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC), esophageal cancer (ESCA), bladder cancer (BLCA), cervical cancer (CESC), and head and neck cancer (HNSC) patients from the TCGA database were used as validation cohorts to test the efficacy of this model. Results: After stratifying the cancer cell lines into high score (HS) and low score (LS) groups according to the median of ferroptosis scores generated by gene set variation analysis, we found that IC50 of 66 agents such as oxaliplatin (p < 0.001) were significantly different, among which 65 were higher in the HS group. 851 genes such as KEAP1 and NRAS were differentially muted between the two groups. Differentially expressed genes, miRNAs and metabolites were also detected-multiple items such as IL17F (logFC = 6.58, p < 0.001) differed between the two groups. Unlike the TCGA data generated by bulk RNA-seq, the gene expression data in DEPMAP are from pure cancer cells, so it could better reflect the traits of tumors in cancer patients. Thus, we built a 15-signature model (AUC = 0.878) based on the gene expression data of cancer cell lines. The validation cohorts demonstrated a higher mutational rate of NFE2L2 and higher expression levels of 12 ferroptosis-related genes in HS groups. Conclusion: This article systemically analyzed multi-omics differences between cancer cell lines with high/low ferroptosis scores and a ferroptosis-related model was developed for multiple cancer types. Our findings could improve our understanding of the role of ferroptosis in cancer and provide new insight into treatment for malignant tumors.

Differences in genetics and microenvironment of lung adenocarcinoma patients with or without TP53 mutation.

BACKGROUND: Differences in genetics and microenvironment of LUAD patients with or without TP53 mutation were analyzed to illustrate the role of TP53 mutation within the carcinogenesis of LUAD, which will provide new concepts for the treatment of LUAD. METHODS: In this study, we used genetics and clinical info from the TCGA database, including somatic mutations data, RNA-seq, miRNA-seq, and clinical data. More than one bioinformatics tools were used to analyze the unique genomic pattern of TP53-related LUAD. RESULTS: According to TP53 gene mutation status, we divided the LUAD patients into two groups, including 265 in the mutant group (MU) and 295 in the wild-type group (WT). 787 significant somatic mutations were detected between the groups, including mutations in titin (TTN), type 2 ryanodine receptor (RYR2) and CUB and Sushi multiple domains 3(CSMD3), which were up-regulated in the MU. However, no significant survival difference was observed. At the RNA level, we obtained 923 significantly differentially expressed genes; in the MU, α-defensin 5(DEFA5), pregnancy-specific glycoprotein 5(PSG5) and neuropeptide Y(NPY) were the most up-regulated genes, glucose-6-phosphatase (G6PC), alpha-fetoprotein (AFP) and carry gametocidal (GC) were the most down-regulated genes. GSVA analysis revealed 30 significant pathways. Compared with the WT, the expression of 12 pathways in the mutant group was up-regulated, most of which pointed to cell division. There were significant differences in tumor immune infiltrating cells, such as Macrophages M1, T cells CD4 memory activated, Mast cells resting, and Dendritic cells resting. In terms of immune genes, a total of 35 immune-related genes were screened, of which VGF (VGF nerve growth factor inducible) and PGC (peroxisome proliferator-activated receptor gamma coactivator) were the most significant up-regulated and down-regulated genes, respectively. Research on the expression pattern of immunomodulators found that 9 immune checkpoint molecules and 6 immune costimulatory molecules were considerably wholly different between the two groups. CONCLUSIONS: Taking the mutant group as a reference, LUAD patients in the mutant group had significant differences in somatic mutations, mRNA-seq, miRNA-seq, immune infiltration, and immunomodulators, indicating that TP53 mutation plays a crucial role in the occurrence and development of LUAD.

Hydrolytically stable foamed HKUST-1@CMC composites realize high-efficient separation of U(VI).

HKUST-1@CMC (HK@CMC) composites that show good acid and alkali resistance and radiation resistance were successfully synthesized by introducing carboxymethyl cellulose (CMC) onto the surface of HKUST-1 using a foaming strategy. For the first time, the composites were explored as efficient adsorbents for U(VI) trapping from aqueous solution, with encouraging results of large adsorption capacity, fast adsorption kinetics, and desirable selectivity toward U(VI) over a series of competing ions. More importantly, a hybrid derivative film was successfully prepared for the dynamic adsorption of U(VI). The results show that ∼90% U(VI) can be removed when 45 mg L-1 U(VI) was passed through the film one time, and the removal percentage is still more than 80% even after four adsorption-desorption cycles, ranking one of the most practical U(VI) scavengers. This work offers new clues for application of the Metal-organic-framework-based materials in the separation of radionuclides from wastewater.

Surfactant-assisted adsorption of uranyl ions in aqueous solution on TiO2/polythiophene nanocomposite.

In this work, hexadecyltrimethylammonium-bromide (HTAB)-modified polythiophene (PTh)/TiO2 nanocomposite (HTAB/PTh/TiO2) was applied to remove uranyl ions (UO22+). FT-IR, XRD, ζ potential, TGA, SEM, and XPS were utilized to obtain the chemical and physical properties of HTAB/PTh/TiO2. The effects of HTAB content, preparation temperature, and adsorption conditions on UO22+ removal were investigated comprehensively. And the UO22+ adsorption process on HTAB/PTh/TiO2 was fitted to the Sips model with a saturated adsorption capacity of 234.74 mg/g, which was 6 times over TiO2. The results suggested that the surfactant of HTAB can significantly improve the adsorption ability of TiO2 for UO22+ ions. This work provides a strategy of surfactant modification for enhancing the separation and recovery ability of adsorbent toward UO22+ in the radioactive wastewater.

Differential expression profiles of microRNAs in musk gland of unmated and mated forest musk deer (Moschus berezovskii).

BACKGROUND: The formation of musk is a complex biophysical and biochemical process that change with the rut of male forest musk deer. We have reported that the mating status of male forest musk deer might result to the variations of chemical composition and microbiota of musk and its yields. Critical roles for microRNAs (miRNAs) of multi-tissues were profiled in our previous study; however, the role for miRNAs of the musk gland remains unclear in this species. METHODS: In this study, we used Illumina deep sequencing technology to sequence the small RNA transcriptome of unmated male (UM) and mated male (UM) of Chinese forest musk deer. RESULTS: We identified 1,652 known miRNAs and 45 novel miRNAs, of which there were 174 differentially expressed miRNAs between UM and MM. chi-miR-21-5p, ipu-miR-99b and bta-miR-26a were up-regulated in UM among the 10 most differentially expressed miRNAs. Functional enrichment of the target genes showed that monosaccharide biosynthetic process, protein targeting, cellular protein catabolic process enriched higher in MM. Meanwhile, structural molecule activity, secretion by cell, regulated exocytosis and circulatory system process enriched more in UM, hinting that the formation of musk in UM was mediated by target genes related to exocytosis. The miRNA-mRNA pairs such as miR-21: CHD7, miR143: HSD17B7, miR-141/200a: Noc2 might involve in musk gland development and musk secretion, which need to be verified in future study.

[Microbial diversity of musk across its maturation process in forest musk deer].

Musk,with unique and intense perfume,was a kind of deep brown precious medicinal material in traditional Chinese medicine. However,the immature musk in musk pot was white and stench. Given the fact that bacterial diversity generated odorous metabolites in animal hosts,in this study,musk samples at three different mature stages,including MJ( the end of June),MA( the end of August) and MO( the end of October) were harvested from three male forest musk deer,and then next-generation sequencing was used to intensively survey the bacterial communities in musk harvested at different mature stages. RESULTS: indicated that the average OTUs per sample at the end of June,August and October were 47 116. 00 ± 1 567. 24( SE),52 009. 00 ± 8 958. 75( SE) and50 004. 67±4 135. 57( SE),respectively. Feature of the musk 16 S rRNA gene showed a total of 418 genera belonging to 52 phyla were observed in all samples. The main microbiota was bacteria,which accounted for 98. 82%,99. 95% and 99. 58% in MJ,MA and MO,respectively. At phylum level,Firmicutes was the most abundant bacterial of MA( 32. 75%) and MO( 39. 19%). While,the major bacterial in MJ was Proteobacteria( 49. 14%). PICRUSt analysis revealed the functions of bacterial in MJ were mainly involved in secretion,while bacterial functions of MA and MO were mainly involved in amino acid or other substance metabolism,which was in accord with the musk secretion physiological process of forest musk deer. This is the first study involved in the bacterial diversity in musk of forest musk deer across the maturation process,while may provide a new insight into the musk generation mechanism.

microRNA and Other Small RNA Sequence Profiling across Six Tissues of Chinese Forest Musk Deer (Moschus berezovskii).

The Chinese forest musk deer (Moschus berezovskii) is an economically important species distributed throughout southwest China and northern Vietnam. Occurrence and development of disease are aggravated by inbreeding and genetic diversity declines in captive musk deer populations. Deep transcriptomics investigation may provide a promising way to improve genetic health of captive and wild FMD population. MicroRNAs (miRNAs), which regulate gene expression by targeting and suppressing of mRNAs, play an important role in physiology and organism development control. In this study, RNA-seq technology was adopted to characterize the miRNA transcriptome signature among six tissues (heart, liver, spleen, lung, kidney, and muscle) in Chinese forest musk deer at two years of age. Deep sequencing generated a total of 103,261,451 (~87.87%) good quality small RNA reads; of them 6,622,520 were unique across all six tissues. A total of 2890 miRNAs were identified, among them 1129 were found to be expressed in all tissues. Moreover, coexpression of 20 miRNAs (>2000RPM) in all six tissues and top five highly expressed miRNAs in each tissue implied the crucial and particular function of them in FMD physiological processes. Our findings of forest musk deer miRNAs supplement the database of transcriptome information for this species and conduce to our understanding of forest musk deer biology.

Isolation, primary culture, and morphological characterization of gland epithelium from forest musk deer (Moschus berezovskii).

Research of epithelial cells in musk gland is lacking. There are no good characterized epithelial cell lines that can provide complementary in vitro models for in vivo research. We successfully cultivated epithelial cells of musk gland for the first time. The protocol described here produces epithelial cell lines from the mature secreting musk gland. Based on morphological observation, epithelial cells of musk gland were isolated and cultured in vitro. After the third passage, the musk gland-derived cells were filled with many lipid droplets and proliferated well. We used gas chromatography and mass spectrometry to explore the chemical composition of lipid droplets in the musk gland-derived cells. The main components of secreted lipid droplet were alkanes, esters, amines, alcohols, ketones, organic acids, and aldehydes. Muscone, which is the main active compound of musk, was not found. This is a new attempt in the field of animal musk to obtain naturally secreted animal musk in vitro by cloning specialized cells. In conclusion, this study provides a reference at the cellular level to further analyze the biology and physiology of the musk gland epithelium and secretion mechanism of musk deer.

Effect of heating parameters on sintering behaviors and properties of mullite whisker frameworks.

Mullite whisker frameworks were fabricated by vapor-solid reaction with SiO2, Al2O3 and AlF3 powders as the whisker forming agent at high temperatures. The effects of heating temperature and soaking time on the weight loss, liner shrinkage, porosity, microstructure and compressive strength were investigated. The results showed that with the increasing of the sintering temperature and soaking time, the weight loss and liner shrinkage of the samples increased and the porosities decreased due to the accelerated vapor-solid reaction, resulting in strong bonding and grain growth of the mullite frameworks. The compressive strength of the samples increased with increasing the sintering temperature from 1500 to 1650°C, and decreased with the soaking time extended to more than 5 h for 1500°C and 2 h for 1650°C. A maximum compressive strength of 142 MPa at a porosity of 62.3% was obtained for the mullite whisker framework heated at 1500°C for 5 h. The enhanced strength was attributed to the strong bonding strength and fine mullite grains resulting from a relative lower heating temperature and a modest soaking time.

Single-Particle Tracking of Human Immunodeficiency Virus Type 1 Productive Entry into Human Primary Macrophages.

Macrophages are one of the major targets of human immunodeficiency virus (HIV-1), but the viral entry pathway remains poorly understood in these cells. Noninvasive virus labeling and single-virus tracking are effective tools for studying virus entry. Here, we constructed a quantum dot (QD)-encapsulated infectious HIV-1 particle to track viral entry at a single-particle level in live human primary macrophages. QDs were encapsulated in HIV-1 virions by incorporating viral accessory protein Vpr-conjugated QDs during virus assembly. With the HIV-1 particles encapsulating QDs, we monitored the early phase of viral infection in real time and observed that, during infection, HIV-1 was endocytosed in a clathrin-mediated manner; the particles were translocated into Rab5A-positive endosomes, and the core was released into the cytoplasm by viral envelope-mediated endosomal fusion. Drug inhibition assays verified that endosome fusion contributes to HIV-1 productive infection in primary macrophages. Additionally, we observed that a dynamic actin cytoskeleton is critical for HIV-1 entry and intracellular migration in primary macrophages. HIV-1 dynamics and infection could be blocked by multiple different actin inhibitors. Our study revealed a productive entry pathway in macrophages that requires both endosomal function and actin dynamics, which may assist in the development of inhibitors to block the HIV entry in macrophages.

Illumina-based de novo transcriptome sequencing and analysis of Chinese forest musk deer.

The Chinese forest musk deer (Moschus berezovskii Flerov) is an endangered artiodactyl mammal. The musk secreted by sexually mature males is highly valued for alleged pharmaceutical properties and perfume manufacturing. However, the genomic and transcriptomic resources of musk deer remain deficiently represented and poorly understood. Next-generation sequencing technique is an efficient method for generating an enormous amount of sequence data that can represent a large number of genes and their expression levels. In the present study, we used Illumina HiSeq technology to perform de novo assembly of heart and musk gland transcriptomes from the Chinese forest musk deer. A total of 239,383 transcripts and 176,450 unigenes were obtained, of which 37,329 unigenes were matched to known sequences in the NCBI nonredundant protein (Nr) database; 31,039 unigenes were assigned to 61 GO terms, and 11,782 to 332 KEGG pathways. Additionally, 592 and 2282 differentially expressed genes were found to be specifically expressed in the heart and musk gland, respectively. The abundant transcriptomic data generated in the present report will provide a comprehensive sequence resource for Chinese forest musk deer as well as lay down a foundation which will help in accelerating genetic and functional genomics research in this species.

The complete nucleotide sequence of the mitochondrial genome of Epicauta aptera Kaszab.

Epicauta aptera Kaszab (E. aptera), an endangered species used to extract cantharidin in Chinese traditional medicine, has a limited geographical distribution in the southwest China. The complete mitochondrial genome of E. aptera is 15 645bp which contains an A + T rich region and 37 genes, including 13 protein-coding genes, 22 tRNA genes and two rRNA genes (GenBank accession No. KX023302). All protein-coding genes are initiated by ATN start codon. Moreover, the largest non-coding A + T-rich region with a length of 1039 bp is at the end of 12S rRNA. It is the first report involved in the complete mitochondrial genome of E. aptera.

Effect of Ammonia Concentration on Silica Spheres Morphology and Solution Hydroxyl Concentration in Stober Process.

Ammonia was used as catalyst to synthesize spherical silica particles by Stober process. More details about the effect of ammonia concentration on the silica powders were investigated. With increase of ammonia concentration from 0.05 to 1.75 mol/L, it was found that particle size increased from 0.068 to 0.91 µm and number density of silica particles decreased rapidly from 9242.40 x 10(10) to 4.62 x 10(10)/mL. Besides, the ratio of standard deviation and the particle size decreased with the increase of ammonia concentration. These results were well consistent with prediction of aggregation model. It was proved that ammonia resulted in persistently high pH values of solutions, which were vital to form large silica spheres. In the formation process of silica spheres, solution hydroxyl concentration was reduced, which might be attributed to transfer of negative charge in hydroxyl groups to silica spheres.

[Research progress on molecular genetics of forest musk deer].

Forest musk deer is one of the large-scale farming musk deer animals with the largest population at the same time. The male musk deer can secrete valuable medicines, which has high medicinal and economic value. Due to the loss of habitat and indiscriminate hunting, the numbers of wild population specie and the distribution have been drastically reduced. Therefore, in-depth understanding of the molecular genetics progress of forest musk deer will pave a way for musk deer protection and breeding. In this review, the progress associated with the molecular marker, genetic classification, artificial breeding, musk secretion and disease in past decades were reviewed, in order to provide a theoretical basis for subsequent molecular genetic researches in forest musk deer.

[Research progress on musk secretion mechanism of forest musk deer].

Forest musk deer (Moschus berezovskii), a rare wild medicinal animal, is listed under the category of the state key protected wildlife list of China. Musk, secreted by the musk glands, is with high economic and medicinal value and used as precious traditional medicine in China. In order to meet the needs of musk in Chinese traditional medicine, forest musk deer farming was conducted in 1950s, but the research progress on musk secretion mechanism was slow. Therefore, by reviewing the histological and anatomical structure of forest musk deer musk gland, the relationship between sex hormones and the musk secretion process, and the molecular mechanism of the musk secretion, the existing problems in investigating the musk secretion mechanism were analyzed and the development trends in this field were also discussed, in order to provide a reference for further studies on the musk secretion mechanism and improve musk production of forest musk deer.