Sex-specific transcription and DNA methylation landscapes of the Asian citrus psyllid, a vector of huanglongbing pathogens

The relationship of DNA methylation and sex-biased gene expression is of high interest, it allows research into mechanisms of sexual dimorphism and the development of potential novel strategies for insect pest control. The Asian citrus psyllid, Diaphorina citri Kuwayama, is a major vector for the causative agents of Huanglongbing (HLB), which presents an unparalleled challenge to citrus production worldwide. Here, we identify the X chromosome of D. citri and investigate differences in the transcription and DNA methylation landscapes between adult virgin males and females. We find a large number of male-biased genes on the autosomes and a depletion of such on the X chromosome. We have also characterized the methylome of D. citri, finding low genome-wide levels, which is unusual for an hemipteran species, as well as evidence for both promoter and TE methylation. Overall, DNA methylation profiles are similar between the sexes but with a small number of differentially methylated genes found to be involved in sex differentiation. There also appears to be no direct relationship between differential DNA methylation and differential gene expression. Our findings lay the groundwork for the development of novel epigenetic-based pest control methods, and given the similarity of the D. citri methylome to some other insect species, these methods could be applicable across agricultural insect pests.</p

Glucitol-core containing gallotannins-enriched red maple (Acer rubrum) leaves extract alleviated obesity via modulating short-chain fatty acid production in high-fat diet-fed mice

Glucitol-core containing gallotannins (GCGs) are characteristic constituents of the red maple (Acer rubrum) species. To pursue the development of red maple for nutraceutical applications, GCGs-enriched red maple leaves extract (MLE) was evaluated for its effects on obesity, gut dysbiosis and short chain fatty acids (SCFAs) production. Our results demonstrated that MLE alleviated high-fat diet-induced obesity, reduced body weight gain and fat mass, improved liver steatosis and insulin resistance, and mitigated adipose hypertrophy and inflammation. Additionally, MLE increased total SCFAs, acetic acid and n-butyric acid content, but exerted no impact on propionic acid production. Moreover, MLE modulated gut microbiota community structure and certain bacteria relative abundance, including Prevotella and Eubacterium. Our work firstly reports a potential association between colon-derived SCFAs production and metabolic improvement due to GCGs-enriched red maple leaves extract administration, and highlights the utilization of red maple gallotannins as a dietary ingredient for preventing obesity and related metabolic diseases

C-X-C Motif Chemokine Ligand 1 Promotes Colitis by Modulating the Gut Microbiota

Introduction: C-X-C motif chemokine ligand 1 (CXCL1) is a potent neutrophil chemoattractant that plays a pivotal role in recruiting neutrophils during inflammatory conditions. This study explored the role of CXCL1 in modulating the gut microbiota, influencing neutrophil infiltration, and contributing to the development of colitis. Methods: We employed quantitative PCR to assess CXCL1 expression in colon samples. A mouse model of dextran sulfate sodium (DSS)-induced colitis was utilized to explore the progression of colitis in wild-type (WT) and CXCL1-deficient (CXCL1−/−) mice. Results: Colitis attenuation was evident in CXCL1−/− mice. Significant alterations were observed in the gut microbiome, as revealed by 16S rRNA gene sequencing. Furthermore, CXCL1−/− mice exhibited reduced gut permeability and diminished endotoxin levels in peripheral blood following DSS treatment compared to WT mice. In response to DSS treatment, WT mice showed a clear increase in neutrophil infiltration, while CXCL1−/− mice exhibited lower levels of infiltration. Fecal microbiota transplantation (FMT) using stools from CXCL1−/− mice alleviated DSS-induced colitis. Interestingly, FMT from patients with colitis increased CXCL1 and Ly6G expression in the colons of gut-sterilized mice. Clinical data analysis revealed elevated CXCL1 and CD15 expression in patients with colitis, with a positive correlation between the severity of colitis and the expression of CXCL1 and CD15. Conclusion: These findings shed light on the pivotal role of CXCL1 in promoting colitis by modulating the gut microbiota

The structure and function of the global citrus rhizosphere microbiome

Citrus is a globally important, perennial fruit crop whose rhizosphere microbiome is thought to play an important role in promoting citrus growth and health. Here, we report a comprehensive analysis of the structural and functional composition of the citrus rhizosphere microbiome. We use both amplicon and deep shotgun metagenomic sequencing of bulk soil and rhizosphere samples collected across distinct biogeographical regions from six continents. Predominant taxa include Proteobacteria, Actinobacteria, Acidobacteria and Bacteroidetes. The core citrus rhizosphere microbiome comprises Pseudomonas, Agrobacterium, Cupriavidus, Bradyrhizobium, Rhizobium, Mesorhizobium, Burkholderia, Cellvibrio, Sphingomonas, Variovorax and Paraburkholderia, some of which are potential plant beneficial microbes. We also identify over-represented microbial functional traits mediating plant-microbe and microbe-microbe interactions, nutrition acquisition and plant growth promotion in citrus rhizosphere. The results provide valuable information to guide microbial isolation and culturing and, potentially, to harness the power of the microbiome to improve plant production and health

Effects of L1-ORF2 fragments on green fluorescent protein gene expression

The retrotransposon known as long interspersed nuclear element-1 (L1) is 6 kb long, although most L1s in mammalian and other eukaryotic cells are truncated. L1 contains two open reading frames, ORF1 and ORF2, that code for an RNA-binding protein and a protein with endonuclease and reverse transcriptase activities, respectively. In this work, we examined the effects of full length L1-ORF2 and ORF2 fragments on green fluorescent protein gene (GFP) expression when inserted into the pEGFP-C1 vector downstream of GFP. All of the ORF2 fragments in sense orientation inhibited GFP expression more than when in antisense orientation, which suggests that small ORF2 fragments contribute to the distinct inhibitory effects of this ORF on gene expression. These results provide the first evidence that different 280-bp fragments have distinct effects on the termination of gene transcription, and that when inserted in the antisense direction, fragment 280-9 (the 3' end fragment of ORF2) induces premature termination of transcription that is consistent with the effect of ORF2

Phylogenetic relationship and characterization of the complete mitochondrial genome of Milionia basalis (Lepidoptera: Geometridae)

Larvae of the geometrid moth Milionia basalis feed exclusively on the podocarp tree, Podocarpus macrophyllus. In this study, we sequenced and analyzed the complete mitochondrial genome (mitogenome) of M. basalis. This mitogenome was 15,901 bp long and encoded 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), and two ribosomal RNA unit genes (rRNAs). The whole mitogenome exhibited heavy AT nucleotide bias (82.2%). Gene order was conserved and identical to most other previously sequenced Geometridae. Most PCGs of M. basalis had the conventional start codons ATN, with the exception of nad1 (TTG) and cox1 (CGA). Except for four genes (cox1, cox2, nad5, and nad4) end with the incomplete stop codon T––, all other PCGs terminated with the stop codon TAA. Phylogenetic analysis showed that M. basalis got together with Apocheima cinerarius, Jankowskia athlete, and four Biston species (B. panterinaria, B. perclara, B. suppressaria, and B. thibetaria)

Silencing of Chitin-Binding Protein with PYPV-Rich Domain Impairs Cuticle and Wing Development in the Asian Citrus Psyllid, Diaphorina citri

Chitin is a major component of the arthropod exoskeleton, always working together with chitin-binding proteins to maintain the functions of extracellular structures. In the present study, we identified a cuticle protein 64 from Diaphorina citri using a chitin-binding assay. Bioinformatics analysis revealed that DcCP64 contained eight conserved PYPV motifs but lacked a Rebers&ndash;Riddiford (R&ndash;R) consensus and other chitin-binding domains. RT-qPCR analysis suggested that DcCP64 had the highest expression level in the wing and fifth-instar nymph stage. Knockdown of DcCP64 by RNA interference (RNAi) resulted in a malformed-wing phenotype, higher mortality and decreased molting rate. Furthermore, transcriptomics analysis revealed that 1244 differentially expressed genes (DEGs) were up-regulated and 580 DEGs were down-regulated, compared with dsDcCP64 groups and dsGFP groups. KEGG enrichment analysis revealed that up-regulated DEGs were mainly related to oxidative phosphorylation, whereas down-regulated DEGs were mainly involved in the MAPK and FoxO signaling pathways. Moreover, inhibition of DcCP64 significantly affected the cuticle surface, and increased the permeability of the abdomen and wings. Further chitin- and cellulose-binding assay confirmed the chitin-binding properties of recombinant DcCP64 in vitro. These results indicate that DcCP64 might play an important role in the cuticle and wing development of D. citri