Microbiota Changes in the Musk Gland of Male Forest Musk Deer During Musk Maturation

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.

Quercetin promotes the secretion of musk by regulating the hormone level and microbial structure of forest musk deer

Musk is a scarce and precious medical resource secreted by male forest musk deer (FMD). Current research to promote musk secretion in FMD has used almost exclusively hormone injections, but this approach can be detrimental to the health of FMD. In order to conserve this endangered species as much as possible while increasing the production of musk, this study first used bioinformatics methods to predict the function of quercetin, a flavonoid that promotes testosterone (T) production and prevents late-onset male hypogonadism. On the basis of good prediction effect, different concentrations of quercetin were added to the diet of FMD. The results showed that quercetin could change the levels of T, luteinizing hormone releasing hormone, luteinizing hormone, and estradiol, and regulate the structure of intestinal microorganisms and musk microorganisms of FMD. Moreover, there is a correlation among musk components, hormones, intestinal microorganisms, and musk microorganisms, which indicates that the production of musk may be regulated by these three at the same time, and the addition of quercetin with 800 mg per kg diet could significantly increase the yield of muscone (P < 0.05), the most effective ingredient in musk. In addition, quercetin decreased the high level of cortisol during musk secretion, which may relieve the stress on FMD in this process. This may help to protect the health of FMD. Combined with the results of software prediction, we finally proposed a possible mechanism for the complex process of musk secretion in FMD with a view to providing ideas for further studies.

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.

Integrated multi-omics analysis reveals insights into Chinese forest musk deer (Moschus berezovskii) genome evolution and musk synthesis

Among the artiodactyls, male animals belonging to the Family Moschidae have a unique tissue, the musk gland, with the capability of musk synthesis. However, the genetic basis of musk gland formation and musk production are still poorly understood. Here, musk gland tissues from two juvenile and three adult Chinese forest musk deer (Moschus berezovskii) were utilized to analyze genomic evolution events, evaluate mRNA profiles and investigate cell compositions. By performing genome reannotation and comparison with 11 ruminant genomes, three expanded gene families were identified in the Moschus berezovskii genome. Transcriptional analysis further indicated that the musk gland displayed a prostate-like mRNA expression pattern. Single-cell sequencing revealed that the musk gland is composed of seven distinguishable cell types. Among them, sebaceous gland cells and luminal epithelial cells play important roles in musk synthesis, while endothelial cells master the regulation of cell-to-cell communication. In conclusion, our study provides insights into musk gland formation and the musk-synthesizing process.

Probiotic characterization of Lactiplantibacillus plantarum HOM3204 and its restoration effect on antibiotic-induced dysbiosis in mice

The purpose of this study was to evaluate the probiotic characteristics of Lactiplantibacillus plantarum HOM3204 isolated from homemade pickled cabbage and to examine its restoration effect on antibiotic-induced dysbiosis in mice. Lact. plantarum HOM3204 tolerated simulated gastric and intestinal juices with a 99.38% survival rate. It also showed strong adhesion ability (3.45%) to Caco-2 cells and excellent antimicrobial activity against foodborne pathogens in vitro. For safety (antibiotic susceptibility) of this strain, it was susceptible to all the tested seven antibiotics. Lact. plantarum HOM3204 had good stability during storage, especially in cold and frozen conditions. Furthermore, Lact. plantarum HOM3204 significantly restored the gut microbiota composition by increasing the abundance of Lactobacilli and Bifidobacteria and decreasing Enterococci, and improved antioxidative function by raising the concentrations of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in serum of antibiotic-induced dysbiosis in mice. These results suggest that Lact. plantarum HOM3204 could be a potential probiotic as a functional food ingredient.

The essential differences in microbial and chemical components of musk of different qualities secreted by captive male forest musk deer (Moschus berezovskii)

Musk is a precious raw material and ingredient in Chinese traditional medicine. The production of unqualified musk has become a puzzling problem in forest musk deer (FMD) breeding. However, what the essential differences between so‐called unqualified musk and mature qualified musk have not yet been elucidated. In this study, 12 musk samples were collected and separated into two groups according to their external properties. One group is white or black cream‐like secretion with sour or unpleasant odour (MM); the other group is brown or blackish brown solid secretion with pleasant fragrance (DM). Next‐generation sequencing and gas chromatography‐mass spectrometry were used to explore the essential differences between the DM and MM groups in microbial and chemical compositions. The results indicate that the DM group has more heterogenous microbial structure but simpler relationships among microbial communities. LEfSe analysis showed that 14 taxa at the genus level could be used to distinguish the DM and MM groups and Bacillus, Paracoccus, tenoteophomonas, Mycobacterium and Leuconostoc were more abundant in the DM group (P < 0.05). In addition, six compounds were identified to specifically distinguish the DM and MM groups under the OPLS‐DA model. PICRUSt analysis revealed that metabolic pathways such as carbohydrate metabolism, nucleotide metabolism, energy metabolism, transport and catabolism were enriched in the DM group. All these findings of differences in microbiota and chemical compositions would provide potential clues for MM quality improvement and new evidence for the scientific establishment of a quality evaluation standard for musk.

Musk (Moschus moschiferus) Attenuates Changes in Main Olfactory Bulb of Depressed Mice: Behavioral, Biochemical, and Histopathological Evidence

BACKGROUND

Musk (Moschus moschiferus) has been described to have a significant impact on the central nervous system, as well as anticonvulsion and antidepressant effects. This study was designed to evaluate the efficacy of musk in alleviating alterations induced in olfactory bulb of depressed mice exposed to chronic stress and identify the mechanism behind it.

METHODS

Fifty male albino mice were divided into five groups (n = 10 each): control, musk, chronic unpredictable mild stress (CUMS), fluoxetine-treated, and musk-treated groups were included in this study. Behavioral changes and serum levels of corticosterone and proinflammatory cytokines included tumor necrosis factor α, interleukin 6, and oxidant/antioxidant profile were assessed at the end of the experiment. Main olfactory bulb (MOB) has been processed for histopathological examination. Gene expression of caspase-3, glial fibrillary acidic protein, and Ki67 were assessed in the MOB using quantitative real-time polymerase chain reaction.

RESULTS

The study showed that musk inhalation significantly reduced (p < 0.001) corticosterone level, immobility time, inflammatory cytokines, and oxidative stress markers in CUMS-exposed mice compared to the untreated CUMS group. Musk lessened CUMS-associated neuronal alterations in the MOB and significantly reduced apoptosis and enhanced neural cell proliferation (p < 0.001) comparable to fluoxetine. Musk significantly enhanced the level of antioxidants in the serum and significantly reduced inflammatory cytokines. The anti-inflammatory and antioxidant activity of musk and its constituents seemed to be behind its neuroprotective effect observed in this study.

CONCLUSION

Musk effectively ameliorated the chronic stress-induced behavioral, biochemical, and neuronal structural changes in MOB mostly through its antioxidant and anti-inflammatory effect.

Study of compositions of musks in different types secreted by forest musk deer (Moschus berezovskii)

Musk is a secretion of the forest musk deer (Moschus berezovskii). Normal musk is a brown solid secretion with a light fragrance. In this study, abnormal types of musk, namely, white and black musks, were discovered during the musk collection process. Researchers have long been concerned with the components of musk. Herein, GC-MS, headspace solid-phase microextraction (HS-SPME), and nonmetric multidimensional scaling (NMDS) were used to analyze the nonpolar organic components, volatile organic components, and sample similarities among different musks, respectively. Abundant steroid hormones and proteins were also found in the musk. The steroid hormone concentrations were detected using a radioimmunoassay (RIA). Proteins in the samples were hydrolyzed and the amino acids concentrations were detected. The steroid hormone and amino acid concentrations in white musk were significantly lower than in normal and black musks (p<0.05). The components were subjected to NMDS analysis to understand the differences in components among different types of musk, with the results suggesting that white musk was different from normal and black musks.

Burying Beetle Parents Adaptively Manipulate Information Broadcast from a Microbial Community

AbstractMicrobial volatiles provide essential information for animals, which compete to detect, respond to, and perhaps control this information. Burying beetle parents have the opportunity to influence microbially derived semiochemicals, because they monopolize a small carcass for their family, repairing feeding holes and applying exudates that alter the microbial community. To study adaptive manipulation of microbial cues, we integrated mechanistic and functional approaches. We contrasted gas chromatography-mass spectrometry (GC-MS) volatile profiles from carcasses that were or were not prepared by a resident pair of Nicrophorus orbicollis. Methyl thiocyanate (MeSCN), the primary attractant for burying beetles seeking a fresh carcass, was reduced 20-fold by carcass preparation, while dimethyl trisulfide (DMTS), which deters breeding beetles, was increased 20-fold. These results suggest that parental care serves to make previously public information more private (crypsis, MeSCN) and to disinform rivals with a deterrent (DMTS). Functional tests in the field demonstrated that carcass preparation reduced discovery and use by congeners (threefold) as well as by dipteran rivals. Because microbes and their chemicals influence nearly every aspect of animal ecology, animal manipulation of microbial cues may be as widespread as manipulation of their own signals.

Muscone Ameliorates LPS-Induced Depressive-Like Behaviors and Inhibits Neuroinflammation in Prefrontal Cortex of Mice

Depression is partially caused by inflammation in the central nervous system. Early study demonstrated that musk, glandular secretion from male musk deer, exerted an antidepressant-like effect. The aim of this study was to investigate if muscone, a bioactive ingredient in musk, could ameliorate neuroinflammation and depressive-like behaviors as well as explore the potential action mechanism. Mice were intraperitoneally (i.p.) injected with muscone for 2 weeks prior to administration of lipopolysaccharides (LPS, 1mg/kg, i.p.). Pre-treatment with muscone reversed the LPS-induced decrease in body weight within 24h and ameliorated depressive-like behaviors shown by sucrose preference, tail suspension test, and forced swimming test. LPS-induced activation of microglial cells and elevation in expression of inflammatory cytokines including IL-1β, RANTES, and MCP-1 in the prefrontal cortex of mice were effectively abrogated by muscone, which significantly down-regulated expression of TLR4, MyD88, Caspase-1, NLRP3, renin, and Ang II. In addition, treatment of BV2 microglia cells with muscone markedly attenuated the LPS-induced rise in protein expression of TLR4, Ang II, and IL-1β. This study revealed that muscone could ameliorate LPS-induced depressive-like behaviors by repressing neuroinflammation in the prefrontal cortex of mice caused by its suppression on microglia activation and production of inflammatory cytokines via acting on TLR4 pathway and RAS cascade.

Body site-specific microbiota reflect sex and age-class among wild spotted hyenas

Host-associated microbial communities, henceforth 'microbiota', can affect the physiology and behavior of their hosts. In mammals, host ecological, social and environmental variables are associated with variation in microbial communities. Within individuals in a given mammalian species, the microbiota also partitions by body site. Here, we build on this work and sequence the bacterial 16S rRNA gene to profile the microbiota at six distinct body sites (ear, nasal and oral cavities, prepuce, rectum and anal scent gland) in a population of wild spotted hyenas (Crocuta crocuta), which are highly social, large African carnivores. We inquired whether microbiota at these body sites vary with host sex or social rank among juvenile hyenas, and whether they differ between juvenile females and adult females. We found that the scent gland microbiota differed between juvenile males and juvenile females, whereas the prepuce and rectal microbiota differed between adult females and juvenile females. Social rank, however, was not a significant predictor of microbiota profiles. Additionally, the microbiota varied considerably among the six sampled body sites and exhibited strong specificity among individual hyenas. Thus, our findings suggest that site-specific niche selection is a primary driver of microbiota structure in mammals, but endogenous host factors may also be influential.