Search

Pine wilt disease (caused by the nematode Bursaphelenchus xylophilus) is extremely harmful to pine forests in East Asia. As a low-resistance pine species, Pinus thunbergii is more vulnerable to pine wood nematode (PWN) than Pinus densiflora and Pinus massoniana. Field inoculation experiments were conducted on PWN-resistant and -susceptible P. thunbergii , and the difference in transcription profiles 24 h after inoculation was analyzed. We identified 2603 differentially expressed genes (DEGs) in PWN-susceptible P. thunbergii , while 2559 DEGs were identified in PWN-resistant P. thunbergii. Before inoculation, DEGs between PWN-resistant and PWN-susceptible P. thunbergii were enriched in the REDOX (Oxidation-Reduction) activity pathway (152 DEGs), followed by the oxidoreductase activity pathway (106 DEGs). After inoculation with PWN, however, the opposite was observed; DEGs were enriched in the oxidoreductase activity pathway (119 DEGs), followed by the REDOX activity pathway (84 DEGs). Before inoculation, according to the metabolic pathway analysis results, we found more genes upregulated in phenylpropanoid metabolic pathways and enriched in lignin synthesis pathways; cinnamoyl-CoA reductase-coding genes related to lignin synthesis were upregulated in PWN-resistant P. thunbergii and downregulated in PWN-susceptible P. thunbergii , and the lignin content was always higher in resistant than in susceptible P. thunbergii. These results reveal distinctive strategies of resistant and susceptible P. thunbergii in dealing with PWN infections. [ABSTRACT FROM AUTHOR]

The pinewood nematode, Bursaphelenchus xylophilus, has been determined as one of the world's top ten plant-parasitic nematodes. It causes pine wilt, a progressive disease that affects the economy and ecologically sustainable development in East Asia. B. xylophilus secretes pathogenic proteins into host plant tissues to promote infection. However, little is known about the interaction between B. xylophilus and pines. Previous studies reported transthyretin proteins in some species and their strong correlation with immune evasion, which has also been poorly studied in B. xylophilus. In this study, we cloned and functionally validated the B. xylophilus pathogenic protein BxTTR-52, containing a transthyretin domain. An in situ hybridization assay demonstrated that BxTTR-52 was expressed mainly in the esophageal glands of B. xylophilus. Confocal microscopy revealed that BxTTR-52-RFP localized to the nucleus, cytoplasm, and plasma membrane. BxTTR-52 recombinant proteins produced by Escherichia coli could be suppressed by hydrogen peroxide and antioxidant enzymes in pines. Moreover, silencing BxTTR-52 significantly attenuated the morbidity of Pinus thunbergii infected with B. xylophilus. It also suppressed the expression of pathogenesis-related genes in P. thunbergii. These results suggest that BxTTR-52 suppresses the plant immune response in the host pines and might contribute to the pathogenicity of B. xylophilus in the early infection stages. [ABSTRACT FROM AUTHOR]

Background: Gastric cancer (GC) is common in East Asia, yet its molecular and pathogenic mechanisms remain unclear. Circular RNAs (circRNAs) are differentially expressed in GC and may be promising biomarkers. Here, we investigated the role and regulatory mechanism of circTMC5 in GC. Methods: CircTMC5 expression was detected in human GC and adjacent tissues using microarray assays and qRT-PCR, while the clinicopathological characteristics of patients with GC were used to assess its diagnostic and prognostic value. The circTMC5/miR-361-3p/RABL6 axis was examined in vitro and vivo, and the immune roles of RABL6 were evaluated using bioinformatics analyses and immunohistochemistry (IHC). Results: CircTMC5 was highly expressed in GC tissues, plasma, and cell lines, and was closely related to histological grade, pathological stage, and T classification in patients with GC. CircTMC5 expression was also an independent prognostic factor for GC and its combined detection with carcinoembryonic antigen may improve GC diagnosis. Low circTMC5 expression correlated with good prognosis, inhibited GC cell proliferation, and promoted apoptosis. Mechanistically, circTMC5 overexpression promoted GC cell proliferation, invasion, and metastasis but inhibited apoptosis by sponging miR-361-3p and up-regulating RABL6 in vitro and vivo, whereas miR-361-3p up-regulation had the opposite effects. RABL6 was highly expressed in GC and was involved in immune regulation and infiltration in GC. Conclusions: CircTMC5 promotes GC and sponges miR-361-3p to up-regulate RABL6 expression, thus may have diagnostic and prognostic value in GC. RABL6 also displays therapeutic promise due to its role in the immune regulation of GC. [ABSTRACT FROM AUTHOR]

• First mitogenome of the superfamily Arionoidea. • Novel gene order for Stylommatophora. • Repeated tandem duplication random loss best explains gene order evolution. Stylommatophora is a main clade of Gastropoda that encompasses approximately 112 gastropod families and may exceed a total of 30,000 species. Twenty-four complete stylommatophoran mitogenomes have been sequenced to date, yet our understanding of mitochondrial evolution in stylommatophorans is still in its infancy. To further expand the set of available mitogenomes, we sequenced the mitogenome of Meghimatium bilineatum (Arionoidea: Philomycidae), a widespread land slug in East Asia. This is the first report on a mitogenome of the superfamily Arionoidea, and indeed on a terrestrial slug. The mitogenome of Meghimatium bilineatum comprises 13,972 bp and exhibits a novel, highly distinctive gene arrangement among the Stylommatophora. Phylogenetic reconstructions based on the sequences of all protein-coding genes consistently recovered Meghimatium bilineatum as sister-group of the Succineidae. A phylogenetic reconstruction based on gene order, however, suggested a highly divergent tree topology, which is less credible when taking into account prior knowledge of stylommatophoran relationships. Our CREx (Common interval Rearrangement Explorer) analysis suggested that three successive events of tandem duplication random loss (TDRL) best explain the evolutionary process of gene order rearrangement in Meghimatium bilineatum from an ancestral stylommatophoran mitogenome. The present example offers new insights into the mechanisms of mitogenome rearrangements in gastropods at large and into the usefulness of mitogenomic gene order as a phylogenetic marker. [ABSTRACT FROM AUTHOR]