摘要: Males evolved plastic strategies to respond to male-male competition and exhibit adaptive traits and behaviors maximizing their access to the females and limiting sperm competition. Mating behaviors allow males to express quick responses to current sexual audience, that is, the number of nearby conspecifics prone to mate. In contrast, physiological responses are frequently delayed because they are constrained by the time and resources having to be mobilized to produce and export sperm and associated products. This is especially critical in species for which males produce spermatophores. Here we investigated in what extend moth males (the tortricid moth Lobesia botrana) producing spermatophores exhibit plastic behavioral and physiological responses to different sexual audiences before and during mating and the consequences for their reproductive output. We found that males adjusted their mating behaviors and spermatophore size to a potentially elevated risk of sperm competition perceived before mating. In addition, males responded to the closed presence of females during mating by reducing their mating duration. Surprisingly, the various behavioral and physiological responses we highlighted here were not fully reflected in their reproductive performance as we did not reveal any effect on fecundity and fertility of their mate. The selective pressure exerted on males experiencing male-male competition could thus be sufficient to trigger adjustment in male mating behaviors but constrains physiological responses according to the perception of competition.

摘要: The development of insect appendages requires the expression of multiple genes in a strict spatial and temporal order. The odd-skipped family genes are vital transcriptional factors involved in embryonic development. The development and morphogenesis of the insect wing requires multiple transcription factors to regulate the expression of wing patterning genes at the transcriptional level. However, the function of odd-related genes in insect wing morphogenesis and development during postembryonic stages is unclear. We focused on the roles of the sister of odd and bowl (sob) gene, a member of odd-skipped family genes, during the wing morphopoiesis in Bombyx mori using the clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 9 system and in Tribolium castaneum by RNA interference. The results showed that the wings were significantly smaller and degenerated, and wing veins were indistinct in the sob gene loss-of-function group in both B. mori and T. castaneum. Quantitative real-time polymerase chain reaction revealed that the Tcsob gene regulated the expression of wing development genes, such as the cht 7 and the vg gene. The findings suggest the importance of sob gene in insect wing morphology formation during postembryonic stages.

摘要: Nutritional mutualism between insects and symbiotic bacteria is widespread. The various sap-feeding whitefly species within the Bemisia tabaci complex associate with the same obligate symbiont (Portiera) and multiple secondary symbionts. It is often assumed that some of the symbionts residing in the whiteflies play crucial roles in the nutritional physiology of their insect hosts. Although effort has been made to understand the functions of the whitefly symbionts, the metabolic complementarity offered by these symbionts to the hosts is not yet well understood. We examined two secondary symbionts, Arsenophonus and Wolbachia, in two species of the B. tabaci whitefly complex, provisionally named as Asia II 3 and China 1. Genomic sequence analyses revealed that Arsenophonus and Wolbachia retained genes responsible for the biosynthesis of B vitamins. We then conducted transcriptomic surveys of the bacteriomes in these two species of whiteflies together with that in another species named MED of this whitefly complex previously reported. The analyses indicated that several key genes in B vitamin syntheses from the three whitefly species were identical. Our findings suggest that, similar to another secondary symbiont Hamiltonella, Arsenophonus and Wolbachia function in the nutrient provision of host whiteflies. Although phylogenetically distant species of symbionts are associated with their respective hosts, they have evolved and retained similar functions in biosynthesis of some B vitamins. Such metabolic complementarity between whiteflies and symbionts represents an important feature of their coevolution.

摘要: Numerous experimental life-history studies on aging are mainly baised on two classical models-fruit fly Drosophila melanogaster (Meigen) and nematode Caenorhabditis elegans (Maupas)-with relatively little attention given to other organisms with different life-history characters. Two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) differs from many other arthropods in that the females continue their growth in the early adult stage and can reproduce sexually and asexually. In this study, the influences of dietary restriction and delayed mating on the aging patterns of the spider mite were examined with the prevailing survival and reproduction trade-off hypothesis of aging being tested. Significant sex-specific responses of the spider mites were found. The females showed longevity extension on diet restriction (fasting for 2 days in every 4 days) compared with their counterparts being fed ad libitum, and after delayed mating for 9 days, while the males displayed a decrease in lifespan when experiencing diet restriction but were not significantly influenced by delayed mating. Path analysis was used to investigate the relationship between mite survival and reproduction traits, including longevity, female lifetime reproduction, age at first reproduction, early reproductive efforts and late reproductive efforts, yielding no evidence for trade-offs between these life-history traits. The additive effects of dietary restriction and delayed mating in lifespan extension of female spider mites were confirmed, proving that diet restriction is a robust anti-aging intervention, and that later onset of reproduction can prolong adult lifespan in females.

摘要: Long noncoding RNAs (lncRNAs) are noncoding transcripts that are more than 200 nucleotides long. They play essential roles in regulating a variety of biological processes in many species, including insects, and some lncRNAs have been found to be associated with insecticide resistance. However, the characteristics and biological functions of lncRNAs involved in indoxacarb resistance are unknown in Spodoptera litura. We performed RNA sequencing in the SS, InRS, and FInRS of S. litura and identified 11 978 lncRNAs, including 3 136 intergenic lncRNAs, 7 393 intronic lncRNAs, and 1 449 anti-sense lncRNAs. Compared with the SS, 51 lncRNAs were upregulated and 134 lncRNAs were downregulated in the two resistant strains, and 908 differentially expressed mRNAs were predicted as the target genes of the 185 differentially expressed lncRNAs. Further analysis showed that 112 of differentially expressed lncRNAs may be associated with indoxacarb resistance by regulating the expression of 14 P450s, seven CCEs, one GST, six UGTs, five ABC transporters, and 24 cuticle protein genes, and 79 of differentially expressed lncRNAs may regulate the expression of 14 detoxification genes and 19 cuticle protein genes to participate in indoxacarb resistance by sponging 10 microRNAs. Interestingly, 47 of differentially expressed lncRNAs may mediate indoxacarb resistance through both lncRNA-mRNA and lncRNA-miRNA-mRNA regulatory pathways. Furthermore, quantitative PCR, RNA interference, and indoxacarb bioassay analyses indicated that overexpressed LNC_004867 and LNC_006576 were involved in indoxacarb resistance. This study provides comprehensive information for lncRNAs of S. litura, and presents evidence that lncRNAs have key roles in conferring insecticide resistance in S. litura.