Moniezia benedeni drives CD3+ T cells residence in the sheep intestinal mucosal effector sites

IntroductionT cells are the core of the cellular immunity and play a key role in the regulation of intestinal immune homeostasis. In order to explore the impact Moniezia benedeni (M. benedeni) infection on distributions of CD3+ T cells in the small intestine of the sheep.MethodsIn this study, sheep pET-28a-CD3 recombinant plasmid were constructed and expressed in BL21 receptor cells, then the rabbit anti-sheep CD3 polyclonal antibody was prepared through recombinant protein inducing. The M. benedeni-infected sheep (infection group, n = 6) and healthy sheep (control group, n = 6) were selected, and the distributions of CD3+ T cells in intestinal laminae propria (LP) and mucous epitheliums were observed and analyzed systematically.ResultsThe results showed that the rabbit anti-sheep CD3 polyclonal antibody had good potency and specificity. In the effector area of small intestine, a large number of CD3+ T cells were mainly diffusely distributed in the intestinal LP as well as in the mucous epitheliums, and the densities of intestinal LP from duodenum to jejunum to ileum were 6.01 cells/104 μm2, 7.01 cells/104 μm2 and 6.43 cells/104 μm2, respectively. Their distribution densities in mucous epitheliums were 6.71 cells/104 μm2, 7.93 cells/104 μm2 and 7.21 cells/104 μm2, respectively; in the infected group, the distributions of CD3+ T cells were similar to that of the control group, and the densities in each intestinal segment were all significantly increased (p < 0.05), meanwhile, the total densities of CD3+ T cells in duodenum, jejunum and ileum were increased by 33.43%, 14.50%, and 34.19%. In LP and mucous epitheliums, it was increased by 33.57% and 27.92% in duodenum; by 25.82% and 7.07% in jejunum, and by 27.07% and 19.23% in ileum, respectively.DiscussionIt was suggested that M. benedeni infection did not change the spatial distributions of CD3+ T cells in the small intestine of sheep, but significantly increased their densities, which lays a foundation for further research on the regulatory mechanism of sheep intestinal mucosal immune system against M. benedeni infection

Enhancement of Flame Retardancy and Mechanical Properties of Polylactic Acid with a Biodegradable Fire-Retardant Filler System Based on Bamboo Charcoal

A cooperative flame-retardant system based on natural intumescent-grafted bamboo charcoal (BC) and chitosan (CS) was developed for polylactic acid (PLA) with improved flame retardancy and minimal decline in strength properties. Chitosan (CS) as an adhesion promoter improved the interfacial compatibility between graft-modified bamboo charcoal (BC-m) and PLA leading to enhanced tensile properties by 11.11% and 8.42%, respectively for tensile strength and modulus. At 3 wt.% CS and 30 wt.% BC-m, the crystallinity of the composite increased to 38.92%, or 43 times that of pure PLA (0.9%). CS promotes the reorganization of the internal crystal structure. Thermogravimetric analysis showed significantly improved material retention of PLA composites in nitrogen and air atmosphere. Residue rate for 5 wt.% CS and 30 wt.% BC-m was 29.42% which is 55.1% higher than the theoretical value of 18.97%. Flammability tests (limiting oxygen index-LOI and UL-94) indicated significantly improved flame retardancy and evidence of cooperation between CS and BC-m, with calculated cooperative effectiveness index(Ce) >1. From CONE tests, the peak heat release rate (pHRR) and total heat release (THR) were reduced by 26.9% and 30.5%, respectively, for 3% CS + 20% BC-m in PLA compared with adding 20% BC-m alone. Analysis of carbon residue morphology, chemical elements and structure suggest CS and BC-m form a more stable char containing pyrophosphate. This char provides heat insulation to inhibit complete polymer pyrolysis, resulting in improved flame retardancy of PLA composites. Optimal mix may be recommended at 20% BC-m + 3% CS to balance compatibility, composite strength properties and flame retardance.Forestry, Faculty ofNon UBCWood Science, Department ofReviewedFacult

Genome-Wide Epigenetic Regulation of Gene Transcription in Maize Seeds

<div><p>Background</p><p>Epigenetic regulation is well recognized for its importance in gene expression in organisms. DNA methylation, an important epigenetic mark, has received enormous attention in recent years as it’s a key player in many biological processes. It remains unclear how DNA methylation contributes to gene transcription regulation in maize seeds. Here, we take advantage of recent technologies to examine the genome-wide association of DNA methylation with transcription of four types of DNA sequences, including protein-coding genes, pseudogenes, transposable elements, and repeats in maize embryo and endosperm, respectively.</p><p>Results</p><p>The methylation in CG, CHG and CHH contexts plays different roles in the control of gene expression. Methylation around the transcription start sites and transcription stop regions of protein-coding genes is negatively correlated, but in gene bodies positively correlated, to gene expression level. The upstream regions of protein-coding genes are enriched with 24-nt siRNAs and contain high levels of CHH methylation, which is correlated to gene expression level. The analysis of sequence content within CG, CHG, or CHH contexts reveals that only CHH methylation is affected by its local sequences, which is different from Arabidopsis.</p><p>Conclusions</p><p>In summary, we conclude that methylation-regulated transcription varies with the types of DNA sequences, sequence contexts or parts of a specific gene in maize seeds and differs from that in other plant species. Our study helps people better understand from a genome-wide viewpoint that how transcriptional expression is controlled by DNA methylation, one of the important factors influencing transcription, and how the methylation is associated with small RNAs.</p></div

Correlation between 24-nt sRNA and DNA methylation in the embryo and endosperm.

<p>(A to D) Correlations between 24-nt sRNA and DNA methylation in protein-coding genes (A), repeats (B), transposable elements (C) and pseudogenes (D). (E to H) Correlations between 24-nt sRNA and CHH methylation in protein-coding genes (A), repeats (B), transposable elements (C) and pseudogenes (D). The dashed line at zero represents the point of alignment.</p

DNA methylation profiles in the embryo and endosperm.

<p>(A to L) Maize B73 RefGen_V2-annotated protein-coding genes [(A), (B), and (C)], repeat regions [(D), (E), and (F)], transposable elements [(G), (H), and (I)] and pseudogenes [(J), (K), and (L)] are aligned at the 5’ end (left) or the 3’end (right), and average methylation levels for each 50-nt interval are plotted from 2 kb away from the gene (negative numbers) to 4 kb into the gene (positive numbers). Embryo methylation is represented by the red trace and endosperm by the blue trace. The dashed line at zero represents the point of alignment. CG methylation is shown in (A), (D), (G), (J), CHG in (B), (E), (H), (K), and CHH in (C), (F), (I) and (L).</p

sRNA associated with gene expression in the embryo.

<p>(A to L) show 21-24-nt sRNAs that regulate protein-coding gene expression [(A), (D), (G) and (J)], pseudogene gene expression [(B), (E), (H), and (K)] and transposable element activity [(C), (F), (I),and (L)]; 21-nt sRNAs are shown in (A), (B), and (C), 22-nt sRNA in (D), (E), and (F), 23-nt sRNA in (G), (H), and (I), and 24-nt sRNA in (J), (K), and (L). Gene expression was classified into five levels according to the number of reads per kilobase per million reads (RPKM, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139582#sec013" target="_blank">Materials and Methods</a>), and the correlation between sRNA accumulation and gene expression was investigated. The dashed line at zero represents the point of alignment. Note that there are only 13 pseudogenes and 20 TEs whose RPKM value is higher than 100 in the embryo, meaning that the sample size was too small to be statistically significant.</p

DNA methylation associated with gene expression in the endosperm.

<p>(A to I) show the relationships between DNA methylation and protein-coding gene expression [(A), (D), and (G)], pseudogene gene expression [(B), (D), and (H)] and transposable element activity [(C), (F), and (I)]; CG methylation is shown in (A), (B), and (C), CHG in (D), (E), and (F), and CHH in (G), (H), and (I). The dashed line at zero represents the point of alignment. As shown in Fig J in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139582#pone.0139582.s001" target="_blank">S1 File</a>, the number of pseudogenes and TEs with RPKM>100 are only 14 and 15 in the embryo, respectively.</p

The allotetraploid origin and asymmetrical genome evolution of the common carp Cyprinus carpio

Common carp (Cyprinus carpio) is an allotetraploid species derived from recent whole genome duplication and provides a model to study polyploid genome evolution in vertebrates. Here, we generate three chromosome-level reference genomes of C. carpio and compare to related diploid Cyprinid genomes. We identify a Barbinae lineage as potential diploid progenitor of C. carpio and then divide the allotetraploid genome into two subgenomes marked by a distinct genome similarity to the diploid progenitor. We estimate that the two diploid progenitors diverged around 23 Mya and merged around 12.4 Mya based on the divergence rates of homoeologous genes and transposable elements in two subgenomes. No extensive gene losses are observed in either subgenome. Instead, we find gene expression bias across surveyed tissues such that subgenome B is more dominant in homoeologous expression. CG methylation in promoter regions may play an important role in altering gene expression in allotetraploid C. carpio.</p

DNA methylation associated with gene expression in the embryo.

<p>(A to I) The relationships between DNA methylation and protein-coding gene expression [(A), (D), and (G)], pseudogene gene expression [(B), (D), and (H)] and transposable element activity [(C), (F), and (I)]; CG methylation is shown in (A), (B), and (C), CHG in (D), (E), and (F), and CHH in (G), (H), and (I). The dashed line at zero represents the point of alignment. As shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139582#pone.0139582.g004" target="_blank">Fig 4</a>, the number of pseudogenes and TEs with RPKM>100 are only 13 and 20 in the embryo, respectively.</p