Population genomics analysis reveals footprints of selective breeding in a rapid-growth variety of Paulownia fortunei with apical dominance.

Paulownia fortunei is an ecologically and economically valuable tree cultivated for its rapid growth and high-quality timber. To enhance Paulownia germplasm, we have developed the elite variety QingT with patented advantages in growth rate and apical dominance. To illuminate the genetic basis of QingT's superior traits, here we harness comparative population genomics to analyze genomic variation patterns between QingT and common Paulownia. We performed whole-genome re-sequencing of 30 QingT and 30 common samples, detecting 15.6 million SNPs and 2.6 million indels. Phylogeny and population structure analyses robustly partitioned common and QingT into distinct groups which indicate robust genome stabilization. QingT exhibited reduced heterozygosity and linkage disequilibrium decay compared to common Paulownia, reflecting high recombination, indicating hybridizing effects with common white-flowered string is the source of its patented advantages. Genome selection scans uncovered 25 regions of 169 genes with elevated nucleotide diversity, indicating selection sweeps among groups. Functional analysis of sweep genes revealed upregulation of ribosomal, biosynthesis, and growth pathways in QingT, implicating enhanced protein production and developmental processes in its rapid growth phenotype. This study's insights comprehensively chart genomic variation during Paulownia breeding, localizing candidate loci governing agronomic traits, and underpinnings of future molecular breeding efforts to boost productivity.

De Novo Assembly and Characterization of the Transcriptome of an Omnivorous Camel Cricket (Tachycines meditationis).

Tachycines meditationis (Orthoptera: Rhaphidophoridae: Tachycines) is a widely distributed insect in eastern Asia. This species is common in urban environments, and its unique omnivorous diet may contribute to its success in various habitats. However, molecular studies on the species are scarce. Here, we obtained the first transcriptome sequence of T. meditationis and performed preliminary analyses to test whether the evolution of coding sequences fits the expectations based on the species' ecology. We retrieved 476,495 effective transcripts and annotated 46,593 coding sequences (CDS). We analysed the codon usage and found that directional mutation pressure was the leading cause of codon usage bias in this species. This genome-wide relaxed codon usage pattern in T. meditationis is surprising, given the potentially large population size of this species. Moreover, despite the omnivorous diet, the chemosensory genes of this species do not exhibit codon usage deviating significantly from the genome-level pattern. They also do not seem to experience more gene family expansion than other cave cricket species do. A thorough search for rapidly evolved genes using the dN/dS value showed that genes associated with substance synthesis and metabolic pathways, such as retinol metabolism, aminoacyl-tRNA biosynthesis, and fatty acid metabolism, underwent species-specific positive selection. While some results seem to contradict the species ecology, our transcriptome assembly provides a valuable molecular resource for future studies on camel cricket evolution and molecular genetics for feeding ecology in insects, in general.

The Chromosome-Level Genome of Hestina assimilis (Lepidoptera: Nymphalidae) Reveals the Evolution of Saprophagy-Related Genes in Brush-Footed Butterflies.

Most butterflies feed on nectar, while some saprophagous butterflies forage on various non-nectar foods. To date, little is known about the genomic and molecular shifts associated with the evolution of the saprophagous feeding strategy. Here, we assembled the high-quality chromosome-level genome of Hestina assimilis to explore its saprophagous molecular and genetic mechanisms. This chromosome-level genome of H. assimilis is 412.82 Mb, with a scaffold N50 of 15.70 Mb. In total, 98.11% of contigs were anchored to 30 chromosomes. Compared with H. assimilis and other Nymphalidae butterflies, the genes of metabolism and detoxification experienced expansions. We annotated 80 cytochrome P450 (CYP) genes in the H. assimilis genome, among which genes belonging to the CYP4 subfamily were significantly expanded (p < 0.01). These P450 genes were unevenly distributed and mainly concentrated on chromosomes 6-9. We identified 33 olfactory receptor (OR), 20 odorant-binding protein (OBP), and six gustatory receptor (GR) genes in the H. assimilis genome, which were fewer than in the nectarivorous Danaus plexippus. A decreased number of OBP, OR, and GR genes implied that H. assimilis should resort less to olfaction and gustation than their nectarivorous counterparts, which need highly specialized olfactory and gustatory functions. Moreover, we found one site under positive selection occurred in residue 996 (phenylalanine) of GR genes exclusive to H. assimilis, which is conservative in most lineages. Our study provides support for the adaptive evolution of feeding habits in butterflies.

Evolution of Gene Arrangements in the Mitogenomes of Ensifera and Characterization of the Complete Mitogenome of Schizodactylus jimo.

Gene arrangement (relative location of genes) is another evolutionary marker of the mitogenome that can provide extensive information on the evolutionary mechanism. To explore the evolution of gene arrangements in the mitogenome of diversified Ensifera, we sequenced the mitogenome of the unique dune cricket species found in China and used it for phylogenetic analysis, in combination with 84 known Ensiferan mitogenomes. The mitogenome of Schizodactylus jimo is a 16,428-bp circular molecule that contains 37 genes. We identified eight types of gene arrangement in the 85 ensiferan mitogenomes. The gene location changes (i.e., gene translocation and duplication) were in three gene blocks: I-Q-M-ND2, rrnl-rns-V, and ND3-A-R-N-S-E-F. From the phylogenetic tree, we found that Schizodactylus jimo and most other species share a typical and ancient gene arrangement type (Type I), while Grylloidea has two types (Types II and III), and the other five types are rare and scattered in the phylogenetic tree. We deduced that the tandem replication-random loss model is the evolutionary mechanism of gene arrangements in Ensifera. Selection pressure analysis revealed that purifying selection dominated the evolution of the ensiferan mitochondrial genome. This study suggests that most gene rearrangements in the ensiferan mitogenome are rare accidental events.

Cadmium-induced genome-wide DNA methylation changes in growth and oxidative metabolism in Drosophila melanogaster.

BACKGROUND: Cadmium (Cd)-containing chemicals can cause serious damage to biological systems. In animals and plants, Cd exposure can lead to metabolic disorders or death. However, for the most part the effects of Cd on specific biological processes are not known. DNA methylation is an important mechanism for the regulation of gene expression. In this study we examined the effects of Cd exposure on global DNA methylation in a living organism by whole-genome bisulfite sequencing (WGBS) using Drosophila melanogaster as model. RESULTS: A total of 71 differentially methylated regions and 63 differentially methylated genes (DMGs) were identified by WGBS. A total of 39 genes were demethylated in the Cd treatment group but not in the control group, whereas 24 showed increased methylation in the former relative to the latter. In most cases, demethylation activated gene expression: genes such as Cdc42 and Mekk1 were upregulated as a result of demethylation. There were 37 DMGs that overlapped with differentially expressed genes from the digital expression library including baz, Act5C, and ss, which are associated with development, reproduction, and energy metabolism. CONCLUSIONS: DNA methylation actively regulates the physiological response to heavy metal stress in Drosophila in part via activation of apoptosis.

Analysis of synonymous codon usage pattern of genes in unique non-blood-sucking leech Whitmania pigra.

Whitmania pigra is a unique, fluid-sucking ectoparasite and an anticoagulant medical leech. The codon usage bias (CUB) is the nonuniform usage of synonymous codons in which some codons are more preferred than others. Here, we performed a comprehensive analysis of CUB of genes in W. pigra, analyzing 140 780 transcripts, 59 553 unigenes, and 20 304 qualified coding sequences (CDSs) from the transcriptomic data of W. pigra. The effective number of codons values suggested that the CUB was low in these genes. We recognized profoundly favored codons in W. pigra that have a G/C-ending. Parity rule two-bias plots suggested that both mutation pressure and natural selection might have influenced the CUB. However, neutrality plots revealed that natural selection might have played a major role while mutation pressure might have played a minor role in shaping the CUB. We applied principal component analysis to relative synonymous codon usage values for divided CDSs based on GC content and codon-ending bases. Codon usage in W. pigra had a general inclination toward C-ending codons and natural selection rather than mutation pressure is the dominant force in the genetic evolution of W. pigra. To our knowledge, this is the first study to describe a complete codon usage analysis of W. pigra; this will increase the understanding of CUB and evolution in W. pigra. The analysis of codon usage patterns in W. pigra aids in understanding its evolution and genetic architecture.

Analysis of codon usage patterns in Hirudinaria manillensis reveals a preference for GC-ending codons caused by dominant selection constraints.

BACKGROUND: Hirudinaria manillensis is an ephemeral, blood-sucking ectoparasite, possessing anticoagulant capacities with potential medical applications. Analysis of codon usage patterns would contribute to our understanding of the evolutionary mechanisms and genetic architecture of H. manillensis, which in turn would provide insight into the characteristics of other leeches. We analysed codon usage and related indices using 18,000 coding sequences (CDSs) retrieved from H. manillensis RNA-Seq data. RESULTS: We identified four highly preferred codons in H. manillensis that have G/C-endings. Points generated in an effective number of codons (ENC) plot distributed below the standard curve and the slope of a neutrality plot was less than 1. Highly expressed CDSs had lower ENC content and higher GC content than weakly expressed CDSs. Principal component analysis conducted on relative synonymous codon usage (RSCU) values divided CDSs according to GC content and divided codons according to ending bases. Moreover, by determining codon usage, we found that the majority of blood-diet related genes have undergone less adaptive evolution in H. manillensis, except for those with homologous sequences in the host species. CONCLUSIONS: Codon usage in H. manillensis had an overall preference toward C-endings and indicated that codon usage patterns are mediated by differential expression, GC content, and biological function. Although mutation pressure effects were also notable, the majority of genetic evolution in H. manillensis was driven by natural selection.

Reassessment of the Phylogenetics of Two Pygmy Grasshopper Generic Groups Tetrix and Systolederus through Mitochondrial Phylogenomics Using Four New Mitochondrial Genome Assemblies.

Mitochondrial genomes offer pragmatic genetic markers to reconstruct evolutionary relationships and inform taxonomic classifications. Here, we present complete mitochondrial sequences for four Chinese pygmy grasshoppers (Tetrigidae), aiming to reevaluate phylogenetic patterns and morphological taxonomy. Our 17,643 bp, 16,274 bp, 15,086 bp, and 15,398 bp mitogenomes of Exothotettix guangxiensis, Formosatettix longwangshanensis, Euparatettix sinufemoralis and Systolederus zhengi, respectively, exhibit archetypal Tetrigidae architecture. We constructed phylogenies using 13 protein-coding loci from 39 Tetrigidae mitogenomes, revealing several genus-level clusters with statistically solid support, conflicts regarding Ex. guangxiensis, F. longwangshanensis merging into Tetrix, and two subclades of Systolederus. The dated divergence analysis indicates over 150 Mya of Tetrigidae ancestry, tracing the Systolederus generic group splits up to ~75 million years ago. Moreover, the Tetrix generic group radiated over 14 Mya across vast distributions, consistent with rapid adaptive dispersals. Our mitochondrial reconstructions suggest that Synstolederus is taxonomically overextended for a single genus, while the distinctiveness of Ex. guangxiensis and F. longwangshanensis from Tetrix appears questionable, and the Tetrix generic group comprises a potential tRNA-Ile coding region. Our integrative mitogenomic approaches will help resolve issues stemming from morphological taxonomy that is reliant on traits that are prone to convergence. This investigation enhances comprehension of Tetrigidae phylogeny and accentuates molecular systematics.

Chromosomal-Level Reference Genome for the Chinese Endemic Pygmy Grasshopper, Zhengitettix transpicula, Sheds Light on Tetrigidae Evolution and Advancing Conservation Efforts.

The pygmy grasshopper, Zhengitettix transpicula, is a Chinese endemic species with an exceedingly limited distribution and fragile population structure, rendering it vulnerable to extinction. We present a high-continuity, chromosome-scale reference genome assembly to elucidate this species' distinctive biology and inform conservation. Employing an integrated sequencing approach, we achieved a 970.40 Mb assembly with 96.32% coverage across seven pseudo-chromosomes and impressive continuity (N50 > 220 Mb). Genome annotation achieves identification with 99.2% BUSCO completeness, supporting quality. Comparative analyses with 14 genomes from Orthoptera-facilitated phylogenomics and revealed 549 significantly expanded gene families in Z. transpicula associated with metabolism, stress response, and development. However, genomic analysis exposed remarkably low heterozygosity (0.02%), implying a severe genetic bottleneck from small, fragmented populations, characteristic of species vulnerable to extinction from environmental disruptions. Elucidating the genetic basis of population dynamics and specialization provides an imperative guideline for habitat conservation and restoration of this rare organism. Moreover, divergent evolution analysis of the CYP305m2 gene regulating locust aggregation highlighted potential structural and hence functional variations between Acrididae and Tetrigidae. Our chromosomal genomic characterization of Z. transpicula advances Orthopteran resources, establishing a framework for evolutionary developmental explorations and applied conservation genomics, reversing the trajectory of this unique grasshopper lineage towards oblivion.

A high-quality chromosome-level genome assembly of the endangered tree Kmeria septentrionalis.

Kmeria septentrionalis is a critically endangered tree endemic to Guangxi, China, and is listed on the International Union for Conservation of Nature's Red List. The lack of genetic information and high-quality genome data has hindered conservation efforts and studies on this species. In this study, we present a chromosome-level genome assembly of K. septentrionalis. The genome was initially assembled to be 2.57 Gb, with a contig N50 of 11.93 Mb. Hi-C guided genome assembly allowed us to anchor 98.83% of the total length of the initial contigs onto 19 pseudochromosomes, resulting in a scaffold N50 of 135.08 Mb. The final chromosome-level genome, spaning 2.54 Gb, achieved a BUSCO completeness of 98.9% and contained 1.67 Gb repetitive elements and 35,927 coding genes. This high-quality genome assembly provides a valuable resource for understanding the genetic basis of conservation-related traits and biological properties of this endangered tree species. Furthermore, it lays a critical foundation for evolutionary studies within the Magnoliaceae family.

Genome Survey Sequencing of the Mole Cricket Gryllotalpa orientalis.

The mole cricket Gryllotalpa orientalis is an evolutionarily, medicinal, and agriculturally significant insect that inhabits underground environments and is distributed globally. This study measured genome size by flow cytometry and k-mer based on low-coverage sequencing, and nuclear repetitive elements were also identified. The haploid genome size estimate is 3.14 Gb by flow cytometry, 3.17 Gb, and 3.77 Gb-based two k-mer methods, respectively, which is well within the range previously reported for other species of the suborder Ensifera. 56% of repetitive elements were found in G. orientalis, similar to 56.83% in Locusta migratoria. However, the great size of repetitive sequences could not be annotated to specific repeat element families. For the repetitive elements that were annotated, Class I-LINE retrotransposon elements were the most common families and more abundant than satellite and Class I-LTR. These results based on the newly developed genome survey could be used in the taxonomic study and whole genome sequencing to improve the understanding of the biology of G. orientalis.

Integrative analysis of microbiota and metabolomics in chromium-exposed silkworm (Bombyx mori) midguts based on 16S rDNA sequencing and LC/MS metabolomics.

The gut microbiota, a complex ecosystem integral to host wellbeing, is modulated by environmental triggers, including exposure to heavy metals such as chromium. This study aims to comprehensively explore chromium-induced gut microbiota and metabolomic shifts in the quintessential lepidopteran model organism, the silkworm (Bombyx mori). The research deployed 16S rDNA sequence analysis and LC/MS metabolomics in its experimental design, encompassing a control group alongside low (12 g/kg) and high (24 g/kg) feeding chromium dosing regimens. Considerable heterogeneity in microbial diversity resulted between groups. Weissella emerged as potentially resilient to chromium stress, while elevated Propionibacterium was noted in the high chromium treatment group. Differential analysis tools LEfSe and random forest estimation identified key species like like Cupriavidus and unspecified Myxococcales, offering potential avenues for bioremediation. An examination of gut functionality revealed alterations in the KEGG pathways correlated with biosynthesis and degradation, suggesting an adaptive metabolic response to chromium-mediated stress. Further results indicated consequential fallout in the context of metabolomic alterations. These included an uptick in histidine and dihydropyrimidine levels under moderate-dose exposure and a surge of gentisic acid with high-dose chromium exposure. These are critical players in diverse biological processes ranging from energy metabolism and stress response to immune regulation and antioxidative mechanisms. Correlative analyses between bacterial abundance and metabolites mapped noteworthy relationships between marker bacterial species, such as Weissella and Pelomonas, and specific metabolites, emphasizing their roles in enzyme regulation, synaptic processes, and lipid metabolism. Probiotic bacteria showed robust correlations with metabolites implicated in stress response, lipid metabolism, and antioxidant processes. Our study reaffirms the intricate ties between gut microbiota and metabolite profiles and decodes some systemic adaptations under heavy-metal stress. It provides valuable insights into ecological and toxicological aspects of chromium exposure that can potentially influence silkworm resilience.

The Comparison of Gut Bacteria Communities and the Functions Among the Sympatric Grasshopper Species From the Loess Plateau.

Gut bacteria exert effects on the health and fitness of their insect hosts. Grasshoppers are an important part of the grassland ecosystem and provide important ecosystem services. As the most valuable feature in grassland ecosystem, the compositions and potential influences of gut bacterial in herbivorous grasshoppers in the same ecological environment are essential but undetermined. To facilitate such studies, we collected nine species of grasshoppers (n = 110) from a rebuild grassland on the Loess Plateau in northern Shaanxi, China, which is a representative area of ecosystem restoration model. We characterized the composition and function of the gut bacteria. We found that 326 OTUs were exhibited in all grasshoppers in which Enterobacter, Pantoea, Bacillus, and Spiroplsma are dominant. Among them, 18 OTUs were shared across all nine species of grasshoppers. The predicted function showed that the majority function of those OTUs were involved in survival dependent processes including membrane transport, carbohydrate metabolism, amino acid metabolism, and DNA replication and repair. The composition of gut bacteria is specific to each grasshopper species, and the bacteria community is most various in Trilophidia annulata. These results highlight the gut bacterial community diversity in different grasshopper species. Our findings are necessary for better understanding the relationships between this important herbivorous insect and their microbiomes and have the potential contribution of evaluating the revegetation and ecosystem management in this area.

Genome Size Estimation and Full-Length Transcriptome of Sphingonotus tsinlingensis: Genetic Background of a Drought-Adapted Grasshopper.

Sphingonotus Fieber, 1852 (Orthoptera: Acrididae), is a grasshopper genus comprising approximately 170 species, all of which prefer dry environments such as deserts, steppes, and stony benchlands. In this study, we aimed to examine the adaptation of grasshopper species to arid environments. The genome size of Sphingonotus tsinlingensis was estimated using flow cytometry, and the first high-quality full-length transcriptome of this species was produced. The genome size of S. tsinlingensis is approximately 12.8 Gb. Based on 146.98 Gb of PacBio sequencing data, 221.47 Mb full-length transcripts were assembled. Among these, 88,693 non-redundant isoforms were identified with an N50 value of 2,726 bp, which was markedly longer than previous grasshopper transcriptome assemblies. In total, 48,502 protein-coding sequences were identified, and 37,569 were annotated using public gene function databases. Moreover, 36,488 simple tandem repeats, 12,765 long non-coding RNAs, and 414 transcription factors were identified. According to gene functions, 61 cytochrome P450 (CYP450) and 66 heat shock protein (HSP) genes, which may be associated with drought adaptation of S. tsinlingensis, were identified. We compared the transcriptomes of S. tsinlingensis and two other grasshopper species which were less tolerant to drought, namely Mongolotettix japonicus and Gomphocerus licenti. We observed the expression of CYP450 and HSP genes in S. tsinlingensis were higher. We produced the first full-length transcriptome of a Sphingonotus species that has an ultra-large genome. The assembly characteristics were better than those of all known grasshopper transcriptomes. This full-length transcriptome may thus be used to understand the genetic background and evolution of grasshoppers.

A new species of the genus Tuberfemurus (Orthoptera: Tetrigoidea: Cladonotinae) with comments on the characters of mitochondrial genome.

A new species, Tuberfemurus viridulus sp. nov. is described and illustrated with photographs. The new species is similar to T. torulisinotus Deng, 2019, but differs from the latter by broader vertex, invisible frontal costa in profile, distinctly truncate apex of hind pronotal process, and two large triangular projections on lower outer carinae of hind femur. An updated key to species of Tuberfemurus is provided. Simultaneously, the complete mitochondrial genome of Tuberfemurus viridulus sp. nov. is sequenced and analyzed. The total length of the assembled mitogenome is 15,060 bp with 37 typical mitochondrial genes and a non-coding region (A + T-rich region). The order and orientation of the gene arrangement pattern are identical to that of most Tetrigoidea species. All PCGs initiate with the standard start codon of ATN, except ATP6 with GAC and ND1 with TTG; and terminate with the complete stop codon (TAA/TAG) or with an incomplete T- codon. This data could provide the genome information available for Tetrigoidea and facilitate phylogenetic studies of related insects.

The complete mitochondrial genome of a grasshopper endemic to the Qinghai-Tibet plateau, Uvaroviola multispinosa (Acrididae: Oedipodinae).

The grasshopper Uvaroviola multispinosa (Acrididae: Oedipodinae), is an agricultural pest to pasture and limitedly distributed in Qinghai-Tibet plateau of China. The complete mitochondrial genome of U. multispinosa is 15,620 bp long, which comprises of 13 protein-coding genes (PCGs), two ribosomal RNA genes, 22 transfer RNA (tRNA) genes and a putative non-coding control region (GenBank accession ID: MK829651). These genes are unequally distributed on different DNA chains, which 23 are located on the majority Chain. The nucleotide composition shows evidently bias (A, C, G, and T was 43.8, 14.8, 10.1, and 31.3%, respectively) with an overall AT content of 75.2%. All PCGs are initiated by ATN codons, among them ATG is the most preferred. Eleven PCGs use a common stop codon of TAA or TAG, whereas the remaining two were terminated with single T as incomplete stop codon. The phylogenetic relationships based on Bayes method showed that U. multispinosa is closely related to Compsorhipis davidiana, which is in accordance with its traditional morphological classification.

Different mitogenomic codon usage patterns between damselflies and dragonflies and nine complete mitogenomes for odonates.

Damselflies and dragonflies, of the order Odonata, have distinct body plans and predatory abilities. Knowledge of their various evolutionary histories will allow for an understanding of the genetic and phenotypic evolution of insects. Mitogenomes are suitable materials to elucidate this, but the mitogenome of only a few odonates have been annotated. Herein, we report the complete mitogenome of nine odonates, including seven dragonflies and two damselflies, and a comprehensive analysis of the codon usage in 31 Odonata mitogenomes with the aim to estimate their evolutionary characteristics. Overall, a weak codon bias exists among odonate mitogenomes, although this favours AT-ending codons. Damselflies have a weaker codon usage bias than dragonflies, and 37 codons have significantly different usages. Both directional mutation and purifying selection shape damselfly and dragonfly mitogenomes. Although inevitable, directional mutation bias plays a minor role, whereas purifying selection pressure is the dominant evolutionary force. A higher selection pressure is observed in dragonflies than in damselflies, but it mainly acts on codon usage patterns rather than amino acid translation. Our findings suggest that dragonflies might have more efficient mitochondrial gene expression levels than damselflies, producing more proteins that support their locomotion and predatory abilities.

The Complete Chloroplast Genomes of Two Lespedeza Species: Insights into Codon Usage Bias, RNA Editing Sites, and Phylogenetic Relationships in Desmodieae (Fabaceae: Papilionoideae).

The genus Lespedeza (tribe: Desmodieae) consists of about 40 species that have high medicinal and economic value. However, in this genus, using morphological characters, the species identification is quite complicated, which can be solved by the analysis of the complete chloroplast genomes. As primary organelle genomes, the complete genome sequences of chloroplasts (cp) provide unique molecular information to study the divergence of species, RNA editing, and phylogeny. Therefore, to the best of our knowledge, for the first time, we sequenced the complete cp genomes of two representative Lespedeza species: Lespedeza davurica and Lespedeza cuneata. The cp genomes of both the species were found to be 149,010 bp in length, exhibiting the typical angiosperm chloroplast structure containing four regions. The Lespedeza cp genomes showed similar conserved gene contents, order, and orientations with a total GC content of 35.0%. A total of 128 genes, including 83 protein-coding genes, 37 tRNAs, and eight rRNAs, were identified from each genome. Unique molecular features of the two Lespedeza cp genome sequences were obtained by performing the analysis of repeats, sequence divergence, codon usage, and predicting the RNA editing sites in addition to phylogenetic analysis with other key genera in tribe Desmodieae. Using the two datasets, the phylogenetic relationship of Lespedeza species among Deasmodieae was discovered, suggesting that whole cp genomes provided useful information for phylogenetic studies of these species.

Draft Genome of a Blister Beetle Mylabris aulica.

Mylabris aulica is a widely distributed blister beetle of the Meloidae family. It has the ability to synthesize a potent defensive secretion that includes cantharidin, a toxic compound used to treat many major illnesses. However, owing to the lack of genetic studies on cantharidin biosynthesis in M. aulica, the commercial use of this species is less extensive than that of other blister beetle species in China. This study reports a draft assembly and possible genes and pathways related to cantharidin biosynthesis for the M. aulica blister beetle using nanopore sequencing data. The draft genome assembly size was 288.5 Mb with a 467.8 Kb N50, and a repeat content of 50.62%. An integrated gene finding pipeline performed for assembly obtained 16,500 protein coding genes. Benchmarking universal single-copy orthologs assessment showed that this gene set included 94.4% complete Insecta universal single-copy orthologs. Over 99% of these genes were assigned functional annotations in the gene ontology, Kyoto Encyclopedia of Genes and Genomes, or Genbank non-redundant databases. Comparative genomic analysis showed that the completeness and continuity of our assembly was better than those of Hycleus cichorii and Hycleus phaleratus blister beetle genomes. The analysis of homologous orthologous genes and inference from evolutionary history imply that the Mylabris and Hycleus genera are genetically close, have a similar genetic background, and have differentiated within one million years. This M. aulica genome assembly provides a valuable resource for future blister beetle studies and will contribute to cantharidin biosynthesis.

Transcriptomics and differential gene expression in Whitmania pigra (Annelida: Clitellata: Hirudinida: Hirudinidae): Contrasting feeding and fasting modes.

The medicinal utility of leeches has been demonstrated through decades of use in modern hospital settings, mainly as relievers of venous congestion following flap or digit replantation surgery. In the present study, we sequence and annotate (through BLAST- and Gene Ontology-based approaches) the salivary transcriptome of the nonblood feeding hirudinid Whitmania pigra and assess the differential gene expression of anticoagulation factors (through both quantitative real-time PCR [qRT-PCR] and in silico-based methods) during feeding and fasting conditions. This was done in order to evince the diversity of putative anticoagulation factors, as well as estimate the levels of upregulation of genes immediately after feeding. In total, we found sequences with demonstrated orthology (via both phylogenetic analyses and BLAST-based approaches) to seven different proteins that have previously been linked to anticoagulatory capabilities-eglin C, bdellin, granulin, guamerin, hyaluronidase, destabilase I, and lipocalin. All of these were recovered from leeches both in the fasting and in the feeding conditions, but all show signs of upregulation in the feeding leeches. Interestingly, our RNA-seq effort, coupled with a hypergeometric test, indicated that the differentially expressed genes were disproportionately involved in three main immunological pathways (endocytosis, peroxisome regulation, and lysosome regulation). The results and implications of the finding of anticoagulants in this nonblood feeding leech and the putative upregulation of anticoagulation factors after feeding are briefly discussed in an evolutionary context.