摘要: Insect herbivores adapt and develop strategies to counteract plant chemical defenses. The aphid Uroleucon formosanum is a serious sap-sucking pest that infests lettuces containing toxic sesquiterpene lactones (STLs). Herein, we employed a combination of genome sequencing and RNA-seq transcriptome profiling to understand the mechanisms underlying phytotoxin tolerance in U. formosanum. We generated the first chromosome-level genome assembly for U. formosanum, with a total size of 453.26 Mb and a scaffold N50 of 33.22 Mb. Comparative genomic analyses revealed an enrichment of signals for positive selection and gene family expansion in immune-related pathways. Specifically, the expanded set of heat shock protein 70 (HSP70) genes showed upregulation after treatment with lactucin, suggesting that they may play a role in the immune response against STLs. The expression of takeout-like genes and cuticle-associated genes was also significantly increased in the lactucin-treated samples. Additionally, 53 cytochrome P450 monooxygenase, 30 carboxylesterase, 19 glutathione S-transferase, 32 uridine diphosphate glycosyltransferase and 63 ATP-binding cassette (ABC) transporter genes were identified in the U. formosanum genome. CYP4C1, CYP6A13 and 7 ABC genes were strongly upregulated in response to lactucin treatment, indicating the involvement of detoxifying enzymes in the tolerance of U. formosanum to STLs. Our findings suggest that the cuticle barrier, immune response and enzyme-mediated metabolic detoxification jointly enhance the tolerance of U. formosanum to phytotoxins and promote its adaptation to host plants. This study presents a valuable genomic resource and provides insights into insect adaptation to plant chemical challenges and future technological developments for pest management.

摘要:

摘要: Insect lytic polysaccharide monooxygenases (LPMO15s) are newly discovered copper-dependent enzymes that promote chitin degradation in insect through oxidative cleavage of glycosidic bonds. They are potential pesticide targets due to their critical role for chitin turnover in the integument, trachea, and peritrophic matrix of the midgut during insect molting. However, the knowledge about whether and how LPMO15s participate in chitin turnover in other tissues is still insufficient. Here, using the orthopteran pest Locusta migratoria as a model, a novel alternative splicing site of LmLPMO15-1 was discovered and it produces 2 variants, LmLPMO15-1a and LmLPMO15-1b. The transcripts of LmLPMO15-1a and LmLPMO15-1b were specifically expressed in the trachea and foregut, respectively. RNA interference targeting LmLPMO15-1 (a common fragment shared by both LmLPMO15-1a and LmLPMO15-1b), a specific region of LmLPMO15-1a or LmLPMO15-1b all significantly reduced survival rate of nymphs and induced lethal phenotypes with developmental stasis or molt failure. Ultrastructure analysis demonstrated that LmLPMO15-1b was specifically involved in foregut old cuticle degradation, while LmLPMO15-1a was exclusively responsible for the degradation of the tracheal old cuticle. This study revealed LmLPMO15-1 achieved tissue-specific functional differentiation through alternative splicing, and proved the significance of the spliced variants during insect growth and development. It provides new strategies for pest control targeting LPMO15-1.

摘要:

摘要: In many animals, drastic changes are observed during sexual maturation characterized by the reproductive system development concomitantly to the sexual behavior ontogenesis. These modifications are under the control of internal and external factors such as food. Sexual maturation requires considerable energetic investment, and diet has been shown to affect reproductive activities in many taxonomic groups, especially in insects and vertebrates. By contrast, diet effects on sexual behavior development remain largely unexplored. To elucidate this aspect, we used the male moth Agrotis ipsilon which undergoes sexual maturation occurring between the third and the fifth day postemergence. During this period, males are sensitive to female sex pheromones and a stereotypical sexual behavior characterized by female-oriented flight takes place. In our study, we compared (1) sex pheromone detection by electroantennography recordings and (2) behavioral response in wind tunnel assays between males fed with different diets found in nature. Compared to standard sucrose diet, males fed with sucrose, fructose, and glucose supplemented with sodium (a mineral element necessary for the locomotor activity in several moths) did not respond better to female sex pheromones but clearly exhibited an earlier behavioral response. Thus, such a diet accelerates the development of sex pheromone-mediated oriented flight, probably by facilitating the central processing of sex pheromone information in male A. ipsilon moths. Our results provide new information on the influence of nutritional intake on the ontogenesis of male sexual behavior in animals.

摘要: Spiders are an abundant group of natural enemies preying on insect pests in agroecosystem. But their potential in biological control has not been fully realized due to difficult mass production. One hindrance is the intense intraspecific aggression in spiders. Neurotransmitters such as serotonin play important roles in modulating aggression. Here, we investigated the regulatory function of serotonin (5-hydroxytryptamine [5-HT]) signaling in the intraspecific aggression in a wandering spider Pardosa pseudoannulata (Araneae, Lycosidae). The aggression was quantified with 5 escalated aggression behaviors as approach, chasing, lunging, boxing, and biting. Virgin (VG) females exhibited higher aggression levels but less 5-HT content than post-reproductive (PR) females. Systemic increase of 5-HT via 5-HT injection decreased aggression, while decrease of 5-HT via RNA interference (RNAi) of the tryptophan hydroxylase gene, increased aggression. The involvement of the four 5-HT receptors were determined via individual or combined RNAi. Co-RNAi of the three 5-HT1 genes increased overall aggression with decreased incidents of approach, chasing, lunging, and increased biting. RNAi of 5-HT1B decreased approach and increased biting, whereas RNAi of 5-HT1A or 5-HT1C did not affect aggression. RNAi of 5-HT7 decreased approach only. Therefore, different 5-HT receptor types contribute to different aspects of the inhibitory effects of 5-HT on aggression and provide several pharmacological targets for manipulating spider aggression. 5-HT injection did not affect spiders' predation on their insect prey, the brown planthopper Nilaparvata lugens. The findings reveal 1 neuronal mechanism regulating intraspecific aggression in spiders and provide an insight in developing aggression suppression strategies for spider mass rearing.

摘要: We describe a new frog species of Ceratobatrachidae, assigned to the genus Liurana, from Medog, Xizang, China. The new species can be distinguished from its congeners by:(1) smaller body size;(2) head length smaller than head width;(3) tibiotarsal articulation reaching between the eye and nostril when adpressed;(4) distinct tympanum;(5) digital disc absent;(6) metacarpal tubercles absent;(7) metatarsal tubercles indistinctive;(8) supernumerary tubercles below the base of finger absent; and(9) finger I much shorter than finger II. Phylogenetic analyses based on a single mitochondrial gene, as well as the combined sequences of one mitochondrial and two nuclear genes, both support the new species as an independent lineage. In addition, the uncorrected genetic distance of COI between the new species and the closest congener, L. xizangensis, was 9.4%. The discovery of another new species of the genus Liurana from the same region suggests that the diversity within this genus requires more comprehensive investigation.

摘要: The genus Ablepharus represents a morphologically diverse group of lizards, comprising approximately 19 species distributed across Asia. However, due to challenges in sample collection, the taxonomy and phylogeny of this genus remain poorly resolved. In this study, we identified and described a novel species of Ablepharus from western Xizang, China, through morphological analysis and molecular phylogenetics. Phylogenetic reconstruction based on mitochondrial DNA（ND2） sequences showed that the new species formed a strongly supported sister lineage with A. ladacensis and A. himalayanus, while exhibiting significant genetic divergence from all other congeners. In addition to its genetic distinctiveness, the new species can be characterized by a combination of the following morphological characters:（1） eyelids partially fused;（2） tympanum sunken;（3） supranasal scales absent;（4） prefrontals separated from each other;（5） supraoculars 4;（6） supralabials 7, 6^th largest;（7） infralabials 6 or 7;（8） scale rows across neck and back 6;（9） scales encircling midbody 32;（10） midventral scales from last chinshield to precloaca 72–80;（11） subcaudals 110–125;（12） lamellae beneath 4^th finger 13–16, beneath 4^th toe 18–21;（13） body brownish-olive, devoid of spots, venter brick-red. This study highlights the underexplored species diversity within Ablepharus in China and provides new insights into the taxonomy and evolutionary relationships of the genus.

摘要: Mitogenomes have been widely used in phylogenetic and taxonomic research, due to their maternal inheritance, accelerated evolutionary rates, compact circular structure, and the absence of introns. Although their utility is well-established, efficient mitogenome sequencing still poses a challenge for evolutionary studies. Here, we presented a novel hybridization capture protocol that enables highfidelity sequencing of the complete mitogenome(16 535 bp) of Odorrana nasuta. This genome exhibits typical anuran characteristics, including an A + T nucleotide bias(56.37%) and conserved gene composition. Notably, we identified a lineage-specific trn H transposition event that reorganizes the typical gene order into a unique trn H-trn L1-trn T-trn P-trn F cluster, which may be a potential synapomorphic trait for the genus Odorrana. Phylogenetic reconstruction using 13 protein-coding genes from 59 anuran species strongly supported the monophyly of Ranidae and its constituent genera(Odorrana, Rana, Lithobates, Amolops, Pelophylax, Glandirana), yet reveals the incongruence in the placement of Hylarana. The conflicting topologies observed for Hylarana and Glandirana across different studies highlight critical methodological limitations, including taxonomic sampling biases and data type dependency, which collectively compromise phylogenetic resolution. By integrating mitogenomic structure signatures with sequence-based phylogenies, this work advances our understanding of the systematics within Odorrana and highlights the need of multi-locus genomic datasets for resolving deep phylogenetic conflicts within Ranidae.

摘要: This study describes Rhabdophis shuichengensis sp. nov. a new species from Guizhou Province, China. This new species is distinguished from other congeners by the following characters:(1) medium-sized body(SVL of adult males: 579–643 mm and adult females: 530 mm);(2) uniformly grayish brown above, black line below eye and between last two labials absent;(3) dorsal scale rows of 15-15-15;(4) ventral scales of 154–158;(5) subcaudal scales of 43–56;(6) supralabials scales 6;(7) infralabials scales 8;(8) preoculars scales 1, postoculars scales 3, and supraocular scales 1;(9) temporal scales 1 + 2;(10) dorsal scales are keeled, with uppermost 5 rows feebly keeled;(11) abruptly enlarged, blade-shaped posterior two maxillary teeth, not preceded by a diastema and maxillary tooth count 20–22(18–20 + 2). The description of this new species brings the total number of described species of this genus to 35 and represents the 14 th known Rhabdophis species in China.