Dark triad and cyber aggression among Chinese adolescents during COVID-19: A moderated mediation model.

During the COVID-19 pandemic, the use of online learning has become a necessary choice for students, and would increase the probability of cyber aggression (CA). Despite the relationship between Dark Triad and CA previous was explored in previous research, the underlying psychological mechanism of CA in adolescents is still unclear. The current study aimed to examine the mediating role of moral disengagement (MD) and the moderating of gender in the relationship between Dark Triad and CA. A sample consists of 501 Chinese adolescents (246 females; 255 males) between the ages of 11 ~ 20. Participants completed the Dirty Dozen Scale, Moral Disengagement Scale, and Cyber Aggressive Behavior Scale. Results show that higher levels of dark personality were associated with higher levels of MD and CA. Moral disengagement partially mediated this positive effects of dark personality on CA. Moreover, gender moderated the mediation model. Specially, the positive relationship between dark triad personality and CA was stronger among females adolescents. These findings advance the understanding of how dark triad personality induces Chinese adolescents' cyber aggressive behavior.

Licochalcone A restrains microphthalmia-associated transcription factor expression and growth by activating autophagy in melanoma cells via miR-142-3p/Rheb/mTOR pathway.

Licochalcone A (LCA) was found to possess anticancer effects. This study aimed to investigate the anticancer effects and mechanisms of LCA in melanoma. A375 and B16 melanoma cells were stimulated with LCA, MTT assay was used to assess cell proliferation. Expression of miR-142-3p, microphthalmia-associated transcription factor (MITF, which regulates melanin production) and autophagy-related genes was determined by Real-time PCR or western blot. The apoptosis was analyzed by flow cytometry and caspase-3 activity. The roles of miR-142-3p and Ras homolog enriched in brain (Rheb) in LCA-affected cells were investigated by gain- and loss-of functions. LCA inhibited proliferation and MITF expression, but increased apoptosis and autophagy of melanoma cells. Moreover, LCA elevated miR-142-3p expression, but decreased its target gene Rheb expression. The effects of LCA on melanoma cells were abrogated by miR-142-3p inhibitor or Rheb overexpression. LCA suppressed mTOR signaling activation via Rheb. Additionally, rapamycin (a mTOR antagonist) notably attenuated the effects of Rheb on the autophagy, proliferation, apoptosis, and MITF expression in LCA-treated melanoma cells. In conclusion, LCA restrained MITF expression and growth by activating autophagy in melanoma cells via miR-142-3p/Rheb/mTOR pathway. This study suggested that LCA might be a potential therapeutic candidate for prevention and treatment of melanoma.

Obligate mutualism within a host drives the extreme specialization of a fig wasp genome.

BACKGROUND: Fig pollinating wasps form obligate symbioses with their fig hosts. This mutualism arose approximately 75 million years ago. Unlike many other intimate symbioses, which involve vertical transmission of symbionts to host offspring, female fig wasps fly great distances to transfer horizontally between hosts. In contrast, male wasps are wingless and cannot disperse. Symbionts that keep intimate contact with their hosts often show genome reduction, but it is not clear if the wide dispersal of female fig wasps will counteract this general tendency. We sequenced the genome of the fig wasp Ceratosolen solmsi to address this question. RESULTS: The genome size of the fig wasp C. solmsi is typical of insects, but has undergone dramatic reductions of gene families involved in environmental sensing and detoxification. The streamlined chemosensory ability reflects the overwhelming importance of females finding trees of their only host species, Ficus hispida, during their fleeting adult lives. Despite long-distance dispersal, little need exists for detoxification or environmental protection because fig wasps spend nearly all of their lives inside a largely benign host. Analyses of transcriptomes in females and males at four key life stages reveal that the extreme anatomical sexual dimorphism of fig wasps may result from a strong bias in sex-differential gene expression. CONCLUSIONS: Our comparison of the C. solmsi genome with other insects provides new insights into the evolution of obligate mutualism. The draft genome of the fig wasp, and transcriptomic comparisons between both sexes at four different life stages, provide insights into the molecular basis for the extreme anatomical sexual dimorphism of this species.

Evolution and expression plasticity of opsin genes in a fig pollinator, Ceratosolen solmsi.

Figs and fig pollinators have co-evolved species-specific systems of mutualism. So far, it was unknown how visual opsin genes of pollinators have evolved in the light conditions inside their host figs. We cloned intact full-length mRNA sequences of four opsin genes from a species of fig pollinator, Ceratosolen solmsi, and tested for selective pressure and expressional plasticity of these genes. Molecular evolutionary analysis indicated that the four opsin genes evolved under different selective constraints. Subsets of codons in the two long wavelength sensitive opsin (LW1, LW2) genes were positively selected in ancestral fig pollinators. The ultraviolet sensitive opsin (UV) gene was under strong purifying selection, whereas a relaxation of selective constrains occurred on several amino acids in the blue opsin. RT-qPCR analysis suggested that female and male fig pollinators had different expression patterns possibly due to their distinct lifestyles and different responses to light within the syconia. Co-evolutionary history with figs might have influenced the evolution and expression plasticity of opsin genes in fig pollinators.

Adaptive evolution of vertebrate-type cryptochrome in the ancestors of Hymenoptera.

One of the most mysterious aspects of insect clock mechanisms is that some insects, including Hymenoptera and Tribolium, only express a vertebrate-type cryptochrome (cry2). It is unknown whether or not cry2 underwent adaptive evolution in these insects. In the present study, we cloned and sequenced the full-length cry2 from a fig pollinator species, Ceratosolen solmsi (Hymenoptera: Chalcidoidea: Agaonidae), and examined the molecular evolution and daily expression of this gene. Our results suggest that cry2 underwent positive selection in the branch leading to hymenopteran insects. The function of CRY2 might have been fixed since undergoing natural selection in the ancestor of Hymenoptera. Male pollinators showed stronger rhythmicity in the host figs, which reflect an adaptation to their life cycles.

Chaos of Wolbachia sequences inside the compact fig syconia of Ficus benjamina (Ficus: moraceae).

Figs and fig wasps form a peculiar closed community in which the Ficus tree provides a compact syconium (inflorescence) habitat for the lives of a complex assemblage of Chalcidoid insects. These diverse fig wasp species have intimate ecological relationships within the closed world of the fig syconia. Previous surveys of Wolbachia, maternally inherited endosymbiotic bacteria that infect vast numbers of arthropod hosts, showed that fig wasps have some of the highest known incidences of Wolbachia amongst all insects. We ask whether the evolutionary patterns of Wolbachia sequences in this closed syconium community are different from those in the outside world. In the present study, we sampled all 17 fig wasp species living on Ficus benjamina, covering 4 families, 6 subfamilies, and 8 genera of wasps. We made a thorough survey of Wolbachia infection patterns and studied evolutionary patterns in wsp (Wolbachia Surface Protein) sequences. We find evidence for high infection incidences, frequent recombination between Wolbachia strains, and considerable horizontal transfer, suggesting rapid evolution of Wolbachia sequences within the syconium community. Though the fig wasps have relatively limited contact with outside world, Wolbachia may be introduced to the syconium community via horizontal transmission by fig wasps species that have winged males and visit the syconia earlier.

Molecular approaches identify known species, reveal cryptic species and verify host specificity of Chinese Philotrypesis (Hymenoptera: Pteromalidae).

Philotrypesis, a major component of the fig wasp community (Hymenoptera: Pteromalidae), is a model taxon for studying male fighting and mating behaviour. Its extreme sexual dimorphism and male polymorphism render species identification uncertain and in-depth research on its ecology, behaviour and other evolutionary topics challenging. The fig wasps' enclosed habitat within the syconia makes their mating behaviour inaccessible, to the extent of matching conspecific females and males. In this study, we combine morphological and molecular analyses to identify species of Philotrypesis sampled from south China and to associate their extraordinarily dimorphic genders and labile male morphologies. Morphological evaluations of females identify 22 species and 28 male morphs. The mitochondrial cytochrome c oxidase I and nuclear internal transcribed spacer 2 data detect 21 species using females, and 15 species among the males. Most of the males match the species as delimited by females. Both markers reveal cryptic species in P. quadrisetosa on Ficus vasculosa. Most species of wasps live on one species of fig but three species co-occur in two hosts (F. microcarpa and F. benjamina), which indicates host switching.