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Evolutionary theory predicts that the spread of cytoplasmic sex ratio distorters leads to the evolution of host nuclear suppressors, although there are extremely few empirical observations of this phenomenon. Here, we demonstrate that a nuclear suppressor of a cytoplasmic male killer has spread rapidly in a population of the green lacewing Mallada desjardinsi. An M. desjardinsi population, which was strongly female-biased in 2011 because of a high prevalence of the male-killing Spiroplasma endosymbiont, had a sex ratio near parity in 2016, despite a consistent Spiroplasma prevalence. Most of the offspring derived from individuals collected in 2016 had 1 : 1 sex ratios in subsequent generations. Contrastingly, all-female or female-biased broods appeared frequently from crossings of these female offspring with males derived from a laboratory line founded by individuals collected in 2011. These results suggest near-fixation of a nuclear suppressor against male killing in 2016 and reject the notion that a non-male-killing Spiroplasma variant has spread in the population. Consistently, no significant difference was detected in mitochondrial haplotype variation between 2011 and 2016. These findings, and earlier findings in the butterfly Hypolimnas bolina in Samoa, suggest that these quick events of male recovery occur more commonly than is generally appreciated.

Two of the most serious agricultural pests, Helicoverpa armigera (Hübner) and Helicoverpa zea (Boddie) (both Lepidoptera: Noctuidae), are similar in their appearances. To distinguish them, morphological characters of female internal genitalia were re-examined. Specimens were collected from 7 regions in 17 countries. All specimens were identified in advance by molecular methods. Significant differences were observed in the length of the bursa copulatrix, ductus bursa, and pigmented area on the base of appendix bursa. Helicoverpa armigera had dense spicules on the luminal surface of the appendix bursa which were absent on the corresponding surface in H. zea. Additionally, differences of length on these parts in female genitalia will be helpful for identification. We are confident these morphological characters will advance resolution of noctuid speciation by taxonomists to properly identify these species based on distinguishing features of the female genitalia.

Confuser® V is a pheromone-based mating disruptant designed to reduce damage caused by seven species of moth pests, including the beet semilooper, Autographa nigrisigna (Lepidoptera: Noctuidae). Eggs and larvae of A. nigrisigna are often found in fields treated with Confuser® V, suggesting that some components in the Confuser® V blend may have adverse effects on the efficacy of mating disruption of this species. Therefore, we examined whether A. nigrisigna perceives heterospecific pheromone components in the Confuser® V blend and delineated the roles of these components with respect to attraction and communication disruption. We found that several heterospecific pheromone components in the Confuser® V blend were perceived by male A. nigrisigna, and the addition of these components to the pheromone blend of A. nigrisigna reduced the attraction of males in the field, and tended to reduce the efficacy of mating disruption in cage bioassays.

Partner discrimination is crucial in mutualistic interactions between organisms to counteract cheating by the partner. Trophobiosis between ants and aphids is a model system of such mutualistic interaction. To establish and maintain the mutualistic association, ants need to correctly discriminate mutualistic aphids. However, the mechanism by which ants recognize aphids as their partners is poorly understood, despite its ecological and evolutionary importance. Here, we show for the first time the evidence that interaction with nest-mates that have tended aphids (Aphis craccivora) allows ants (Tetramorium tsushimae) to learn to recognize the aphid species as their partner. When ants had previously tended aphids, they moderated their aggressiveness towards aphids. More importantly, ants that had interacted with aphid-experienced nest-mates also reduced their aggressiveness towards aphids, even though they had never directly experienced them, indicating that aphid information was transmitted from aphid-experienced ants to inexperienced ants. Furthermore, inhibition of mouth-to-mouth contact (trophallaxis) from aphid-experienced ants to inexperienced ants by providing the inexperienced ants with artificial honeydew solution caused the inexperienced ants to become aggressive towards aphids. These results, with further supporting data, strongly suggest that ants transfer information on their mutualists during trophallactic interactions.

Helicoverpa armigera (Hübner) is a notorious agricultural pest native to the Old World. Recently, its invasion into South and Central America has become a serious problem in the New World. The rapid detection of invasive pests is essential to eradicate them and prevent establishment. However, an extremely similar species, H. zea (Boddie) distributed in the New World makes identification difficult. Helicoverpa armigera and H. zea have only minor differences in male genitalia to separate them morphologically. Both species are attracted to the same pheromone lure, and it takes considerable time and effort to identify them from bulk samples obtained during trap monitoring. Although several molecular approaches based on PCR have been reported, these methods require expensive equipment and are unsuitable for onsite diagnostics. Here, we developed a rapid and convenient diagnostic method based on the loop-mediated isothermal amplification to distinguish H. armigera from related species: H. zea, H. assulta (Guenée), H. punctigera (Wallengren), and Chloridea virescens (Fabricius). The diagnostic method makes it possible to detect H. armigera within 90 min only using simple equipment. The method also worked with mixed DNA templates containing excess DNA from H. zea at the ratio of 1:999 (H. armigera:H. zea). This method can be an effective tool for onsite diagnostics during monitoring surveys for invasive H. armigera.

For maternally transmitted microbes, a female-biased host sex ratio is of reproductive advantage. Here we found a strong female bias in a field population of the green lacewing, Mallada desjardinsi (Insecta; Neuroptera). This bias was attributed to the predominance of individuals harboring a maternally inherited male-killing bacterium that was phylogenetically closely related to the plant-pathogenic Spiroplasma phoeniceum and Spiroplasma kunkelii. Among 35 laboratory-reared broods produced by wild-caught females, 21 broods (60%)-all infected with Spiroplasma-consisted of only females (940 individuals). Among 14 broods consisting of both males and females (516 and 635 individuals, respectively), 4 broods were doubly infected with Spiroplasma and Rickettsia, 6 broods were singly infected with Rickettsia, and 3 broods were uninfected (remaining one brood was unknown). Mortality during embryonic and larval development was prominent in all-female broods but not in normal sex ratio broods. Following antibiotic treatment on all-female broods, mortality was significantly reduced and the sex ratio was restored to 1:1. Strong expression and high prevalence of this male-killer is remarkable considering its low density (~10-5-10-4 cells per host mitochondrial gene copy based on quantitative PCR). In addition, a bacterium closely related to Rickettsia bellii was present in 25 of 34 broods (73.5%), irrespective of the sex ratio, with the infection density comparable to other cases of endosymbiosis (~10-2-10-1 cells per mitochondrial gene copy). Higher density of Rickettsia than Spiroplasma was also demonstrated by electron microscopy which visualized both Spiroplasma-like cells and Rickettsia-like cells inside and outside the ovarian cells.

Background Wolbachia are maternally inherited arthropod endosymbionts known for their diverse effects on host reproduction, which serve to increase their prevalence in host populations. As Wolbachia spreads, the frequency of the associated mitochondrial DNA (mtDNA) haplotypes tends to increase within the host population. Two distinct Wolbachia strains, w CI and w Fem, are shared by two pierid butterfly sister species: Eurema mandarina and Eurema hecabe . The congruence of mtDNA phylogeny and Wolbachia infection status suggests hybrid introgression of mtDNA from E. hecabe to E. mandarina . This inference is based on the observation that uninfected E. mandarina have unique mtDNA haplotypes, distinct from the mtDNA haplotypes found in Wolbachia -infected E. mandarina and E. hecabe . In E. hecabe , Wolbachia infection has been considered fixed, with no expectation of uninfected individuals. Results Unexpectedly, Wolbachia- free E. hecabe individuals were discovered on the Yonaguni Island of Japan. We included these individuals in the phylogenetic analyses to reassess the impact of Wolbachia infection on Eurema butterflies . The nuclear Triosephosphate isomerase gene-based phylogenetic tree formed two discrete clades corresponding to E. mandarina and E. hecabe . Contrastingly, the mitochondrial cytochrome c oxidase subunit I gene-based tree consisted of three clades, Wolbachia -free E. mandarina , Wolbachia -free E. hecabe , and a clade consisting of Wolbachia -infected E. mandarina and E. hecabe, as well as two other Eurema species, Eurema ada and Eurema lacteola . Conclusions Our findings indicate that the mitochondria shared by E. mandarina and E. hecabe likely originate from a different species of Eurema ( E. ada , E. lacteola , or others). Although the origin was not identified, our results indicate that Wolbachia provides significant evolutionary advantages to the associated mtDNA haplotypes across multiple Eurema species, leading to a complex mtDNA phylogeny.

The majority of low‐grade isocitrate dehydrogenase‐mutant (IDH mt ) gliomas undergo malignant progression (MP), but their underlying mechanism remains unclear. IDH mt gliomas exhibit global DNA methylation, and our previous report suggested that MP could be partly attributed to passive demethylation caused by accelerated cell cycles. However, during MP, there is also active demethylation mediated by ten‐eleven translocation, such as DNA hydroxymethylation. Hydroxymethylation is reported to potentially contribute to gene expression regulation, but its role in MP remains under investigation. Therefore, we conducted a comprehensive analysis of hydroxymethylation during MP of IDH mt astrocytoma. Five primary/malignantly progressed IDH mt astrocytoma pairs were analyzed with oxidative bisulfite and the Infinium EPIC methylation array, detecting 5‐hydroxymethyl cytosine at over 850,000 locations for region‐specific hydroxymethylation assessment. Notably, we observed significant sharing of hydroxymethylated genomic regions during MP across the samples. Hydroxymethylated CpGs were enriched in open sea and intergenic regions ( p  < 0.001), and genes undergoing hydroxymethylation were significantly associated with cancer‐related signaling pathways. RNA sequencing data integration identified 91 genes with significant positive/negative hydroxymethylation‐expression correlations. Functional analysis suggested that positively correlated genes are involved in cell‐cycle promotion, while negatively correlated ones are associated with antineoplastic functions. Analyses of The Cancer Genome Atlas clinical data on glioma were in line with these findings. Motif‐enrichment analysis suggested the potential involvement of the transcription factor KLF4 in hydroxymethylation‐based gene regulation. Our findings shed light on the significance of region‐specific DNA hydroxymethylation in glioma MP and suggest its potential role in cancer‐related gene expression and IDH mt glioma malignancy.

Background Achalasia is a rare condition characterized by dysfunction of esophageal motility and impaired relaxation of the lower esophageal sphincter. Anesthetic management of these patients is challenging due to the elevated risk of regurgitation and aspiration. Case presentation A 53-year-old man diagnosed with achalasia was scheduled for renal cancer surgery before esophageal myotomy. Since his severe dysphagia suggested the possibility of vomiting and aspiration under anesthesia, a stomach tube was inserted before induction of general anesthesia. After preoxygenation, rapid sequence induction was performed and an antiemetic was administered to prevent postoperative vomiting. Although anesthetic management was uneventful, the inserted stomach tube coiled up in the dilated esophagus and substantial residue was aspirated via the tube even after a prolonged fasting period. Conclusion Anesthesiologists should be familiar with achalasia even though it is an uncommon disease, since affected patients are at risk of regurgitation and aspiration under anesthesia.

In ant-aphid associations, many aphid species provide ants with honeydew and are tended by ants, whereas others are never tended and are frequently preyed upon by ants. In these relationships, ants must have the ability to discriminate among aphid species, with mutualistic aphids being accepted as partners rather than prey. Although ants reportedly use cuticular hydrocarbons (CHCs) of aphids to differentiate between mutualistic and non-mutualistic species, it is unclear whether the ability to recognize mutualistic aphid species as partners is innate or involves learning. Therefore, we tested whether aphid recognition by ants depends on learning, and whether the learning behavior is species-specific. When workers of the ant Tetramorium tsushimae had previously tended the cowpea aphid, Aphis craccivora , they were less aggressive toward this species. In addition, ants also reduced their aggressiveness toward another mutualistic aphid species, Aphis fabae , after tending A. craccivora , whereas ants remained aggressive toward the non-mutualistic aphid, Acyrthosiphon pisum , regardless of whether or not they had previous experience in tending A. craccivora . When ants were offered glass dummies treated with CHCs of these aphid species, ants that had tended A. craccivora displayed reduced aggression toward CHCs of A. craccivora and A. fabae . Chemical analyses showed the similarity of the CHC profiles between A. craccivora and A. fabae but not with A. pisum . These results suggest that aphid recognition of ants involves learning, and that the learning behavior may not be species-specific because of the similarity of CHCs between different aphid species with which they form mutualisms.