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Objective The present study aims to investigate the clinical features and diagnostic characteristics of children with Cohen syndrome caused by the vacuolar protein sorting 13 homolog B (VPS13B) gene mutation and to review the relevant literature to provide a reference for genetic counseling and the diagnosis of Cohen syndrome. Methods The clinical data and molecular genetic test results of a child with Cohen syndrome were retrospectively analyzed and a review of the relevant literature was conducted. Results A two-year-and-four-month-old boy was referred to the hospital for recurrent fever and shortness of breath. On physical examination, the boy was found to have growth retardation, thick bushy hair, microcephaly, hypertelorism, down-slanting palpebral fissures, and hypotonia. Genetic testing was performed, and the results suggested the presence of exon 20–32 heterozygous deletion and c.8275 delC (p.R2759 fs*18) heterozygous variant on the VPS13B gene from phenotypically normal parents. These two mutation loci have not been reported in the literature, and they were predicted by relevant software to be pathogenic variants. Conclusion We identified two novel variants in the VPS13B gene (exon 20–32 heterozygous deletion and c.8275 delC heterozygous variant) in a boy with Cohen syndrome, thus extending the spectrum of VPS13B gene variants in patients with Cohen syndrome.

S-(-)-trans-Verbenol (1) and its antipode, R-(+)-trans-verbenol (1') have been confirmed as the critical pheromone components of bark beetles. Synthesis of these two active secondary alcohols (1 and 1') from commercially available starting materials S-α-pinene and R-α-pinene was reported. The key steps were mainly depended on the effective SN2 stereo-inversion of the hydroxy group of sterically hindered alcohols (3 and 3'), using Mitsunobu reaction or hydrolysis of mesylate ester, alternatively. Our results provide a new and stereo-selectivity way to obtain optically active insect pheromones.

The larvae of Ips typographus and Ips subelongatus can cause extensive damage to coniferous trees under their bark, resulting in severe economic losses within the forestry industry. In this study, we analyzed and compared the sensilla on the antennae and mouthparts of the larvae of these two species to identify biology- and taxonomy-related differences using scanning electron microscopy. In general, no significant differences in sensilla type or distribution on the antennae and mouthparts of the larvae were observed between the two species. However, some sensilla lengths, basal widths, and quantities varied greatly between the species. Two types of sensilla were observed on the antennae: sensilla basiconica (B.a.1) and sensilla twig basiconica (T.b.1 and T.b.2). The mouthparts had five types of sensilla: sensilla trichodea (T.r.1 and T.r.2), sensilla chaetica (C.h), B.a.2, T.b.3–T.b.5, and sensilla placodea (P.l). We also discuss the function of each type of sensilla based on their morphologies and locations. The results provide a theoretical basis for further studies on the electrophysiology and feeding behaviors of I. typographus and I. subelongatus larvae.

Background Micromelalopha siversi (Staudinger) (Lepidoptera: Notodontidae) is a defoliator of poplar trees, Populus spp. (Salicaceae). In our previous study, 13,15-octadecadienal has been conformed as a female-produced candidate sex pheromone component of M. siversi, but the Z/E stereochemistry of the 1,3-diene system has not been identified so far. Results Four unsaturated aliphatic aldehydes, Z13,E15-18:Ald, Z13,Z15-18:Ald, E13,E15-18:Ald, and E13,Z15-18:Ald, were synthesized from the commercially available 12-bromo-1-decanol mainly by alkylation of lithium alkyne, normal Wittig or Wittig-Schlosser olefination, and hydroboration-protonolysis. According to gas chromatography (GC) analysis of pheromone gland extracts, Z13,E15-18:Ald was the main component, and a small amount of Z13,Z15-18:Ald was also detected, with a ratio of approximately 7:3. However, the results of GC-electroantennographic detection (GC-EAD) showed that Z13,E15-18:Ald was the only compound with electrophysiological activity, whereas Z13,Z15-18:Ald elicited no activity. In the field, traps baited with only Z13,E15-18:Ald resulted in much superior results to those with Z13,Z15-18:Ald as well as the Z13,E15-18:Ald and Z13,Z15-18:Ald binary mixture. Conclusions Based on geometrically selective synthesis and bioactivity tests, the active sex pheromone component of M. siversi has been identified as Z13,E15-18:Ald, the pheromone component that has not been identified in Lepidoptera before. The synthetic component was attractive to male moths in preliminary field traps, which provides novel technologies to monitor and control this pest.

The spruce bark beetle (Ips typographus L.) is a destructive pest of Eurasian spruce forests. Although the gut bacteria of this insect are considered to play important roles in its lifecycle, the relationship between I. typographus and its gut bacterial community is poorly characterized. In this study, 16S rRNA gene sequencing was used to determine gut bacterial community composition across successive I. typographus life stages. Responses of the gut bacteria to α-pinene enantiomers were also explored. Ips typographus gut bacterial populations were dominated by the phyla Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, and the relative abundance of these phyla varied across different developmental stages of the beetle. Bacterial species diversity and richness indices increased with developmental stage progression. Relative abundances of the dominant genera, Erwinia (Enterobacteriales: Enterobacteriaceae), Pseudoxanthomonas (Xanthomonadales: Xanthomonadaceae), Serratia (Enterobacteriales: Enterobacteriaceae), and Romboutsia (Clostridiales: Peptostreptococcaceae), also varied across successive I. typographus life stages. Large disparities in the gut bacterial community of male adults were observed when the beetles were treated with S-(–)-α-pinene and R-(+)-α-pinene. The relative abundances of Lactococcus (Lactobacillales: Streptococcaceae) and Lelliottia (Enterobacteriales: Enterobacteriaceae) increased drastically with R-(+)-α-pinene and S-(–)-α-pinene treatment, respectively. This indicated a distinct enantiomer-specific effect of α-pinene on the I. typographus gut bacteria. This study demonstrated the plasticity of gut bacteria during I. typographus development, when α-pinene host monoterpenes are encountered. This study provides new insights into the relationship between ‘I. typographus–gut bacteria’ symbionts and host trees.

The symbiosis between the bark beetle (Ips subelongatus) and its fungal symbiont (Endoconidiophora fujiensis) poses a serious threat to larch forests. However, the signaling pathways between these symbiotic partners and their host/non-host trees are not fully understood. Inoculation of the host larch (Larix principis-rupprechtii) with two strains of E. fujiensis induced a rapid and long-term release of monoterpenes. Although the fungi had a level of tolerance to these compounds, many monoterpenes inhibited fungal growth in culture. Moreover, monoterpenes with stronger inhibitory effects on fungal growth exhibited weaker synergistic effects on the attraction of I. subelongatus to aggregation pheromone. Surprisingly, individual isomers of aggregation pheromone components promoted fungal symbiont growth in a culture medium. Non-host volatiles (NHVs) were tested and shown to completely inhibit the growth of fungal symbionts in culture but had no effects on beetle responses to aggregation pheromone, with the exception of (Z)-3-hexen-1-ol. These results reveal convergence and mutualism patterns in the evolution of I. subelongatus and E. fujiensis with respect to host tree volatiles but not in response to NHVs. Ultimately, we put forward a hypothesis that host plants are ecological and evolutionary determinants of bark beetle–fungus symbioses in terms of their complex signaling interactions.

Dendrolimus spp. are important destructive pests of conifer forests, and Dendrolimus punctatus Walker (Lepidoptera; Lasiocampidae) is the most widely distributed Dendrolimus species. During periodic outbreaks, this species is said to make "fire without smoke" because large areas of pine forest can be quickly and heavily damaged. Yet, little is known about the molecular mechanisms that underlie the unique ecological characteristics of this forest insect. Here, we combined Pacific Biosciences (PacBio) RSII single-molecule long reads and high-throughput chromosome conformation capture (Hi-C) genomics-linked reads to produce a high-quality, chromosome-level reference genome for D. punctatus. The final assembly was 614 Mb with contig and scaffold N50 values of 1.39 and 22.15 Mb, respectively, and 96.96% of the contigs anchored onto 30 chromosomes. Based on the prediction, this genome contained 17,593 protein-coding genes and 56.16% repetitive sequences. Phylogenetic analyses indicated that D. punctatus diverged from the common ancestor of Hyphantria cunea, Spodoptera litura and Thaumetopoea pityocampa ~ 108.91 million years ago. Many gene families that were expanded in the D. punctatus genome were significantly enriched for the xenobiotic biodegradation system, especially the cytochrome P450 gene family. This high-quality, chromosome-level reference genome will be a valuable resource for understanding mechanisms of D. punctatus outbreak and host resistance adaption. Because this is the first Lasiocampidae insect genome to be sequenced, it also will serve as a reference for further comparative genomics.

Graphite-like carbon films were deposited on silicon substrates in plasma nitriding system with propane and hydrogen. Scanning electron microscope, X-ray photoelectron spectroscopy, Raman spectroscopy, atomic force microscope, and contact angle measurement method were used to investigate the effect of voltage, duty cycle, and gas composition on the growth thickness, hydrogen content, atomic bond structure, surface roughness, surface morphology, and wettability of the films. It is shown that the thickness of the films decreased with the voltage and duty cycle increasing. The voltage, duty cycle and gas composition have a significant effect on the sp2/sp3 bonds and hydrogen content, which can produce the a-C:H films characterized by sp2 bonding (over 70%). As the voltage and duty cycle improved, the surface morphology of the film progressed from a rugged surface with wide hillsides to a flat level surface. This work will provide a novel method to produce graphite-like carbon films with lubricating and anti-wear properties and give direction on designing high-performance tribo-systems for industrial applications.

The association between insects and fungi has evolved over millions of years and is ubiquitous in nature. This symbiotic relationship holds critical implications for both partners, the insects and the associated microbes. Numerous fungi are externally allied with bark beetles and form a close symbiosis, but the community structures of these fungi are largely unknown. In Yunnan Province in southwestern China, the beetles Tomicus yunnanensis, T. minor, and T. brevipilosus are major forest pests that cause large losses of two indigenous pines, Pinus yunnanensis and P. kesiya. In this study, we used the Illumina MiSeq PE300 platform to process 48 samples of epibiotic fungal communities pooled from 1348 beetles, the beetles were collected during both the branch- and trunk-infection sections from five locations across Yunnan Province. Considerably greater species richness was detected using high-throughput sequencing of amplified internal transcribed spacer 1 (ITS1) ribosomal DNA (rDNA) libraries than previously documented by using culture-dependent methods. In total, 1,413,600 reads were generated, and a 97% sequence-similarity cutoff produced eight phyla, 31 classes, 83 orders, 181 families, 331 genera, 471 species, and 1157 operational taxonomic units (OTUs), with 659, 621, and 609 OTUs being confined to T. yunnanensis, T. minor, and T. brevipilosus, respectively. Tomicus yunnanensis, T. minor, and T. brevipilosus had the similar OTUs richness and evenness of fungal communities in Yunnan Province, nevertheless, the two fungal community compositions associated with T. yunnanensis and T. minor were structurally similar to each other but distinct from that associated with T. brevipilosus. Lastly, the results of principal co-ordinates analysis suggested that epibiotic fungal community structures of the three Tomicus spp. were conditioned strongly by the locations and pine hosts but weakly by beetle species and infection sections. Our findings provide baseline knowledge regarding the epibiotic fungal communities of three major Tomicus spp. in southwestern China.

The release rhythm of volatiles is an important physiological characteristic of plants, because the timing of release can affect the function of each particular volatile compound. However, most studies on volatiles release rhythms have been conducted using model plants, rather than crop plants. Here, we analyzed the variations in volatile compounds released from healthy and leafminer (Liriomyza huidobrensis)-infested kidney bean (Phaseolus vulgaris), an important legume crop plant, over a 24 h period. The constituents of the volatiles mixture released from plants were analyzed every 3 h starting from 08:00. The collected volatiles were identified and quantified by gas chromatography–mass spectrometry. Undamaged kidney bean plants released trace amounts of volatiles, with no obvious release rhythms. However, leafminer-damaged plants released large amounts of volatiles, in two main peaks. The main peak of emission was from 17:00 to 20:00, while the secondary peak was in the early morning. The terpene volatiles and (Z)-3-hexenyl acetate showed similar rhythms as that of total volatiles. However, the green leaf volatile (Z)-3-hexen-ol was emitted during the night with peak emission in the early morning. These results give us a clear picture of the volatiles release rhythms of kidney bean plants damaged by leafminer.