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Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) are histone-modifying and -binding complexes that mediate the formation of facultative heterochromatin and are required for silencing of developmental genes and maintenance of cell fate1–3. Multiple pathways of RNA decay work together to establish and maintain heterochromatin in fission yeast, including a recently identified role for a conserved RNA-degradation complex known as the rixosome or RIX1 complex4–6. Whether RNA degradation also has a role in the stability of mammalian heterochromatin remains unknown. Here we show that the rixosome contributes to silencing of many Polycomb targets in human cells. The rixosome associates with human PRC complexes and is enriched at promoters of Polycomb target genes. Depletion of either the rixosome or Polycomb results in accumulation of paused and elongating RNA polymerase at Polycomb target genes. We identify point mutations in the RING1B subunit of PRC1 that disrupt the interaction between PRC1 and the rixosome and result in diminished silencing, suggesting that direct recruitment of the rixosome to chromatin is required for silencing. Finally, we show that the RNA endonuclease and kinase activities of the rixosome and the downstream XRN2 exoribonuclease, which degrades RNAs with 5′ monophosphate groups generated by the rixosome, are required for silencing. Our findings suggest that rixosomal degradation of nascent RNA is conserved from fission yeast to human, with a primary role in RNA degradation at facultative heterochromatin in human cells.

Foamy macrophages containing prominent cytoplasmic lipid droplets (LDs) are found in a variety of infectious diseases. However, their role in Streptococcus uberis-induced mastitis is unknown. Herein, we report that S. uberis infection enhances the fatty acid synthesis pathway in macrophages, resulting in a sharp increase in LD levels, accompanied by a significantly enhanced inflammatory response. This process is mediated by the involvement of fatty acid binding protein 4 (FABP4), a subtype of the fatty acid-binding protein family that plays critical roles in metabolism and inflammation. In addition, FABP4 siRNA inhibitor cell models showed that the deposition of LDs decreased, and the mRNA expression of Tnf, Il1b and Il6 was significantly downregulated after gene silencing. As a result, the bacterial load in macrophages increased. Taken together, these data demonstrate that macrophage LD formation is a host-driven component of the immune response to S. uberis. FABP4 contributes to promoting inflammation via LDs, which should be considered a new target for drug development to treat infections.

Background Morinda officinalis How (MO) is a perennial herb distributed in tropical and subtropical regions, which known as one of the “Four Southern Herbal Medicines”. The extent of genetic variability and the population structure of MO are presently little understood. Here, nine morphological traits, six chemical components and Single nucleotide polymorphism (SNP) markers were used in integrative research of MO germplasm variation among 88 individuals collected from ten populations across four geographical provinces of China. Results Both phenotype and chemical composition have significant genetic variation, and there is a certain correlation between them such as root diameter and the nystose content, as well as geographical distribution. The principal component analysis (PCA) showed the leaf length, leaf width, nystose, 1F-furanosaccharide nystose, and the section color were the major contributors to diversity. The cluster analysis based on phenotypic and oligosaccharide data distinguished three significant groups, which was consistent with the result of a corresponding analysis with 228,615 SNP markers, and importantly, they all showed a significant correlation with geographical origin. However, there was little similarity between two cluster results. The Shannon’s information index (I) varied from 0.17 to 0.53 with a mean of 0.37, suggesting a high level of genetic diversity in MO populations, which mainly existed among individuals within populations, accounting for 99.66% of the total according to the analysis of molecular variance (AMOVA) results. Each population also maintains the connection because of certain gene communication, so that the genetic differentiation between populations was not very significant. The STRUCTURE software was used to analyse the population structure and the result showed that 88 accessions were clustered into three groups, and 67% of them were pure type, which was also confirmed through PCA. Conclusions The comprehensive study of phenotypic, chemical and molecular markers will provide valuable information for future breeding plans and understanding the phylogenetic relationship of MO population.

In this work, a large size of macroporous phenolic resin (PR)/bacterial cellulose (BC) composite with double-network structure was fabricated simply by soaking, heating, solvent exchange, and ambient pressure drying. The mechanism and influence factors for the fabrication of this macroporous composite were systematically elaborated. One network of macroporous composite was composed of PR beads, and the other derived from original BC nanofibers. They supported and reinforced each other, avoiding the collapse of interconnected porous structure and achieving low density (0.29 g/cm3), high porosity (77.7%), low thermal conductivity (0.10 W/m K), and excellent compressive strength (7.97 ± 2.24 MPa). Through further carbonization, carbon counterpart that maintained fine structure and good performance can also be obtained. The surface of macroporous composite was extremely hydrophilic. On the contrary, its carbon counterpart possessed a highly hydrophobic surface (contact angle = 118.2°). These properties suggest that the macroporous composite and carbon counterpart may have potential applications for filtration, separation, and thermal insulation materials. Moreover, this work will provide a novel perspective for the fabrication of porous composites with BC as the template and 3D nanofiber reinforcement simultaneously.

Monolithic titania (TiO2) aerogel was fabricated by using bacterial cellulose (BC) as the bio-template and preceramic polymer as titanium resource, via freeze-drying and two-step calcination process. As-prepared TiO2 aerogel BCTi-air-2 h possessed low bulk density (0.04 g/cm3) and moderate mechanical strength. SEM images showed that TiO2 aerogel was composed of 3D reticulate TiO2 nanofibers. The anatase crystalline structure of TiO2 with crystal size around several nanometers was revealed by XRD measurements. N2 adsorption/desorption analysis indicated that TiO2 aerogel possessed high specific area (115 m2/g) and macroporous structure, which contributed to the high photocatalytic activity. Most importantly, the monolithic state will ease the usage, recycling, and regeneration of TiO2 aerogel as photocatalyst.

Understanding habitat quality and landscape connectivity and exploring corridors connecting habitat patches are crucial for conservation, particularly for species distributed among isolated populations. The Sichuan golden snub-nosed monkey, Rhinopithecus roxellana, is an Endangered primate species endemic to mountainous forests in China. Its easternmost distribution lies in the Shennongjia area, which harbors an isolated subspecies, R. roxellana hubeiensis. Unfortunately, it has experienced significant habitat loss, fragmentation, and dramatic population decline in recent decades, primarily due to increased human disturbance. To quantify habitat quality, identify suitable habitat patches, and detect possible linkages among these patches for R. roxellana hubeiensis, we conducted habitat suitability assessments and landscape connectivity analyses in the Shennongjia area based on a set of environmental factors. We created a habitat quality model and a movement cost surface for the Shennongjia area based on a habitat suitability index, graph theory, expert knowledge, field experience, and information from the literature. Our results show that suitable habitat for R. roxellana hubeiensis in Shennongjia is fragmented and limited, and that this is particularly true for highly suitable habitats. We detected six core habitat patches and six least-cost paths and corridors. Our study does not provide accurate distributions of the monkeys and their habitat use. However, it identifies the most feasible and traversable habitats and corridors, which should be conservation priorities for this subspecies, and provides valuable guidance for reevaluating habitat conservation plans.

Male-male competition and female mate choice based on ornamentation and genetic traits are the main drivers of animal sexual selection and group spawning. If male-male competition is intense, males with specific phenotypes should have advantages in breeding success or occupying superior mating positions. If female choice is important, females should have preferences for mate relatedness or males with good genes or optimal genetic compatibility against themselves. To detect the intensities of male-male competition and female choice and test the good genes and genetic compatibility hypotheses, we observed breeding behaviors, measured individual body lengths and breeding success indicators, and calculated male genetic heterozygosity, male–female relatedness, and genetic dissimilarity in an Omei treefrog (Rhacophorus omeimontis) population in Badagongshan, China. Our analyses showed that larger males obtained larger mates, had more mating opportunities, occupied better amplectant positions, and produced more offspring. However, females showed no inbreeding/outbreeding bias in mate choice, and the good genes and genetic compatibility hypotheses were not supported in female selection on mates and amplectant positions. We considered male-male competition as the main driver of sexual selection and group spawning in this prolonged mating species because the cost of choosing mates with specific genetic traits may be high for females. Male-male competition and female mate choice are the main drivers of animal sexual selection and mating behaviors. However, their impacts on the evolution of mating system are not yet quite clear. By studying the Omei treefrog, a Chinese endemic anuran species with common group spawning behaviors, this research posed the importance of male-male competition and female mate choice and discussed the mechanisms of sexual selection and multiple mating, which are the most essential and debated issues in evolutionary biology and behavioral ecology. We found that, in this prolonged mating and lek-patterned species, male-male competition is the main driver of sexual selection and group spawning. Larger males can get larger females, have more breeding opportunities, occupy better amplectant positions, and thus, obtain greater numbers of offspring. Whereas, females have no significant preferences on ornamentation and genetic traits of their males or mating positions, and the inferior males “make the best of a bad lot” by joining mating pairs to produce mating groups. Our study provides empirical evidence of reproductive mechanisms of amphibian species and could advance the understandings on the evolution of animals’ sexual selection and mating system.

The objective of this study was to investigate the expression level, clinical significance, and possible regulating role of IL-17F in patients of chronic periodontitis. Periodontal local tissues were obtained from chronic periodontitis (CP) and healthy controls (HC) for real-time PCR (RT-PCR) detection with IL-17F and IL-17A messenger RNA (mRNA). Primary human gingival fibroblasts (HGF) were derived from patients receiving crown-lengthening procedures. Efficiency of small interfering RNA (siRNA) of IL-17R to HGF cells were assessed by Western blot and RT-PCR. Recombinant IL-17F and IL-17A were used to stimulate the HGF cells compared with the control group. Aspects of the nuclear factor-kappa B (NF-κB) and extracellular signal-regulated kinase (ERK) signaling pathways were examined by Western blot. Production of pro-inflammatory cytokines induced by IL-17F and IL-17A was detected by RT-PCR. Statistical analysis was analyzed by SPSS software. It showed significantly elevated levels of IL-17F and IL-17A mRNA in CP gingival tissues compared with HC group (P

Telomeres, the ends of linear eukaryotic chromosomes, are tandem DNA repeats and capped by various telomeric proteins. These nucleoprotein complexes protect telomeres from DNA damage response (DDR), recombination, and end-to-end fusions, ensuring genome stability. The human telosome/shelterin complex is one of the best-studied telomere-associated protein complexes, made up of six core telomeric proteins TRF1, TRF2, TIN2, RAP1, POT1, and TPP1. TPP1, also known as adrenocortical dysplasia protein homolog (ACD), is a putative mammalian homolog of TEBP-β and belongs to the oligonucleotide binding (OB)-fold-containing protein family. Three functional domains have been identified within TPP1, the N-terminal OB fold, the POT1 binding recruitment domain (RD), and the carboxyl-terminal TIN2-interacting domain (TID). TPP1 can interact with both POT1 and TIN2 to maintain telomere structure, and mediate telomerase recruitment for telomere elongation. These features have indicated TPP1 play an essential role in telomere maintenance. Here, we will review important findings that highlight the functional significance of TPP1, with a focus on its interaction with other telosome components and the telomerase. We will also discuss potential implications in disease therapies.

Sexual selection is critical to both reproduction and evolution. The effects of male–male competition and female choice regarding body size have been examined in a large number of taxa, including toad species. Males and females have different optimal reproductive strategies, achieving breeding advantages in discrepant ways. Further, the relative contributions of intra- and inter-sexual size selection vary among species. Thus, to understand the mechanisms affecting mating success, it is important to consider both male–male and male–female interactions simultaneously and elucidate their interrelationship. In this study, we measured body sizes of all mated and unmated individuals in a population of Asiatic toad (Bufo gargarizans) and counted fertilized eggs of several clutches. Based on correlation and regression techniques, we tested for female choice and intra-sexual competition among males relative to body size gradients, and we compared the relative importance of these two processes for mating success. Our results reveal that male–male competition and female choice simultaneously contribute to sexual selection in toads. Furthermore, both interactions are most intense among smaller toads. The synergistic trends of male–male competition and female choice support the mutual mate choice hypothesis and works to stabilize body size in B. gargarizans. Normal distributions of breeding success relative to body size were detected for both sexes, suggesting that medium-sized individuals enjoy a reproductive advantage in the population studied.

This study aims to compare the expression levels of interleukin (IL)-17 and IL-23 in local periodontal tissues from patients with both chronic periodontitis and oral lichen planus (CP-OLP), patients with chronic periodontitis (CP) only, patients with oral lichen planus (OLP) only, and healthy controls (HC). The periodontal tissues were collected from 15 CP-OLP patients, 15 CP patients, 15 OLP patients, and 10 healthy controls. Immunohistochemistry (IHC) and real-time quantitative PCR (qPCR) was performed to investigate the protein and mRNA expression level of IL-17 and IL-23 in periodontal lesions from these four groups. IHC statistical analysis showed that the expression level of IL-17- and IL-23p19-positive cells significantly increased in CP-OLP group compared with that in CP (P

The objective of this study was to compare the expression levels of interleukin (IL)-17 IL-17 and IL-23 in serum from patients with both oral lichen planus and chronic periodontitis (OLP-CP), patients only with oral lichen planus (OLP), patients only with chronic periodontitis (CP), and healthy controls (HC). The serum samples were collected from 35 OLP-CP patients, 35 OLP patients, 30 CP patients, and 30 healthy controls. ELISA test was used to detect expression levels of IL-17 and IL-23 in serum from these four groups. ELISA analysis showed significantly elevated levels of serum IL-17 in OLP-CP group compared with OLP group (P

Animal skin, which is the tissue that directly contacts the external surroundings, has evolved diverse functions to adapt to various environments. Amphibians represent the transitional taxon from aquatic to terrestrial life. Exploring the molecular basis of their skin function and adaptation is important to understand the survival and evolutionary mechanisms of vertebrates. However, comprehensive studies on the molecular mechanisms of skin functions in amphibians are scarce. In this study, we sequenced the skin transcriptomes of seven anurans belonging to three families and compared the similarities and differences in expressed genes and proteins. Unigenes and pathways related to basic biological processes and special functions, such as defense, immunity and respiration, were enriched in functional annotations. A total of 108 antimicrobial peptides were identified. The highly expressed genes were similar in species of the same family but were different among families. Additionally, the positively selected orthologous groups were involved in biosynthesis, metabolism, immunity and defense processes. This study is the first to generate extensive transcriptome data for the skin of seven anurans and provides unigenes and pathway candidates for further studies on amphibian skin function and adaptation.