Effect of heavy metals pollution on the composition and diversity of the intestinal microbial community of a pygmy grasshopper (Eucriotettix oculatus).

Heavy metal pollution in the environment is mostly manifested as a multi-elemental compound pollution. The effect of the long-term exposure to heavy metal pollution on the gut microbes of insects has remained unknown. For the current work, the population of Eucriotettix oculatus living in mining areas around the Diaojiang River with a history of hundreds of years of pollution, was selected along with the similar species living in non-mining areas to conduct a comparative study of their gut microbes. The microbial communities were analyzed using 16S rRNA amplicon sequencing. The results showed Proteobacteria to be dominant among gut microbes of E. oculatus, but the abundance of Proteobacteria was significantly increased when the insects were exposed to the environment with heavy metal pollution. The symbiotic bacteria belonging to genus Wolbachia were found to be dominant among the insect population from the non-mining area group, while the pathogenic bacteria belonging to Aeromonas were dominant among the insect population of the mining area group. The diversity analysis showed that the gut microbial community diversity of E. oculatus was reduced in the heavy metal pollution habitat. The analysis of the differences in the gut microbial population and metabolic pathways of the two groups showed that the heavy metal pollution caused the increase in pathogenic bacteria among the gut microbes of E. oculatus, which might have a negative impact on the health of the host. At the same time, probiotics and the beneficial metabolism pathways were also found to increase and enhance, helping the host to resist the damage caused by heavy metal stress. This might be one of the strategies used by E. oculatus to adapt to heavy metal pollution.

Integrative analysis of microbiota and metabolomics in chromium-exposed silkworm (Bombyx mori) midguts based on 16S rDNA sequencing and LC/MS metabolomics.

The gut microbiota, a complex ecosystem integral to host wellbeing, is modulated by environmental triggers, including exposure to heavy metals such as chromium. This study aims to comprehensively explore chromium-induced gut microbiota and metabolomic shifts in the quintessential lepidopteran model organism, the silkworm (Bombyx mori). The research deployed 16S rDNA sequence analysis and LC/MS metabolomics in its experimental design, encompassing a control group alongside low (12 g/kg) and high (24 g/kg) feeding chromium dosing regimens. Considerable heterogeneity in microbial diversity resulted between groups. Weissella emerged as potentially resilient to chromium stress, while elevated Propionibacterium was noted in the high chromium treatment group. Differential analysis tools LEfSe and random forest estimation identified key species like like Cupriavidus and unspecified Myxococcales, offering potential avenues for bioremediation. An examination of gut functionality revealed alterations in the KEGG pathways correlated with biosynthesis and degradation, suggesting an adaptive metabolic response to chromium-mediated stress. Further results indicated consequential fallout in the context of metabolomic alterations. These included an uptick in histidine and dihydropyrimidine levels under moderate-dose exposure and a surge of gentisic acid with high-dose chromium exposure. These are critical players in diverse biological processes ranging from energy metabolism and stress response to immune regulation and antioxidative mechanisms. Correlative analyses between bacterial abundance and metabolites mapped noteworthy relationships between marker bacterial species, such as Weissella and Pelomonas, and specific metabolites, emphasizing their roles in enzyme regulation, synaptic processes, and lipid metabolism. Probiotic bacteria showed robust correlations with metabolites implicated in stress response, lipid metabolism, and antioxidant processes. Our study reaffirms the intricate ties between gut microbiota and metabolite profiles and decodes some systemic adaptations under heavy-metal stress. It provides valuable insights into ecological and toxicological aspects of chromium exposure that can potentially influence silkworm resilience.

The mitochondrial genome sequence of a satyrid butterfly, Lethe confuse (Lepidoptera: Nymphalidae: Satyrinae).

The nearly complete mitochondrial genome (mitogenome) of Lethe confuse was sequenced and analyzed. This mitogenome is 14,945 bp in size and encodes 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes. The most common start codon is ATN (ATA, ATG, and ATT), and the most common termination codon is TAA. In addition, three PCGs have incomplete termination codon T. The overall nucleotide composition is 38.0% of A, 7.8% of G, 42.4% of T, and 11.8% of C. The data will increase the basic information of Satyrinae phylogenetic research and can help to better understand the phylogenetic status of L. confuse in Nymphalidae.

The complete mitochondrial genome of Appias albina (Lepidoptera: Pieridae) and phylogenetic analysis.

The complete mitochondrial genome of Appias albina (Lepidoptera: Pieridae) was firstly sequenced and characterized in our study. The total length of mitogenome is 15,193 bp and contains 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and 1 A + T-rich region. The overall nucleotide composition was 38.4% of A, 8.0% of G, 40.9% of T, and 12.4% of C. Phylogenetic tree was reconstructed using Bayesian Inference (BI) to validate the taxonomic status of A. albina, exhibiting the close relationship with Appias remedios.

First record of mitochondrial genome of Teredorus nigropennis (Orthoptera: Tetrigidae) and phylogenetic analysis.

The nearly complete mitochondrial genome (mitogenome) of Teredorus nigropennis was determined and analyzed. This mitogenome was 14,652 bp in size and encoded 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes. The most common start codon is ATN, the most common termination codon is TAA and two genes have incomplete termination codon T (TA). The overall nucleotide composition was 45.2% of A, 10.2% of G, 28.6% of T, and 16.1% of C. The data will increase the basic information of Tetrigidae phylogenetic research and can help to better understand the phylogenetic status of T. nigropennis in Tetrigiodea.