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1.
Nature ; 633(8031): 840-847, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39261731

ABSTRACT

Parasitoid wasps are exceptionally diverse and use specialized adaptations capable of manipulating the physiology and behaviour of host organisms1. In more than two centuries since the first records of Drosophila-parasitizing wasps, nearly 200 described and provisional parasitoid species of drosophilids have been identified2. These include endoparasitoids and ectoparasitoids, as well as species attacking larval and pupal hosts3. Despite a deep history of research attention and remarkable biodiversity, a wasp species that attacks and develops inside the adult stage of a fly host has not been described previously. Here we report the discovery of a wasp species that infects the adult stage of fruit flies in the genus Drosophila, including one of the most deeply studied model organisms in biology, Drosophila melanogaster. Notably, this wasp can be easily collected from backyard fly baits and has a broad geographic distribution throughout the eastern USA. We document its life history and unique host interactions, including egg-laying into and larval emergence from adult flies, and provide protocols to raise wasps from wild-caught host flies. Our results emphasize the need for ongoing research investment in insect biodiversity and systematics. As parasitoid research continues to uncover unusual biology and supports fundamental mechanistic insights into immunity4, metabolism5, ecology6, evolution7-9 and behaviour10-12, we anticipate that this wasp's association with the laboratory model organism, D. melanogaster, will provide new research opportunities across the life sciences.


Subject(s)
Aging , Drosophila , Host-Parasite Interactions , Wasps , Animals , Female , Male , Biodiversity , Drosophila/classification , Drosophila/growth & development , Drosophila/parasitology , Drosophila melanogaster/growth & development , Drosophila melanogaster/parasitology , Host-Parasite Interactions/physiology , Larva/parasitology , Oviposition , Wasps/classification , Wasps/growth & development , Wasps/pathogenicity , Wasps/physiology , United States
2.
Genome ; 67(7): 243-255, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38593475

ABSTRACT

This study characterizes the chromosomal organization of DNA repetitive sequences and the karyotypic evolution in four representatives of the solitary wasp genus Trypoxylon using conventional and molecular cytogenetic techniques. Our findings present the first cytogenetic data for Trypoxylon rogenhoferi (2n = 30) and Trypoxylon albonigrum (2n = 32), while the karyotypes of Trypoxylon nitidum (2n = 30) and Trypoxylon lactitarse (2n = 30) were similar to those previously described. Fluorochrome staining and microsatellite distribution data revealed differences in the constitutive heterochromatin composition among species. Trypoxylon nitidum and T. albonigrum exhibited one major rDNA cluster, potentially representing an ancestral pattern for aculeate Hymenoptera, while T. rogenhoferi and T. lactitarse showed two pericentromeric rRNA gene sites, suggesting amplification events in their ancestral clade. The (TCAGG)n motif hybridized in the terminal regions of the chromosomes in all four Trypoxylon species, which may suggest that this sequence represents DNA telomeric repeat. Notably, the presence of this repetitive sequence in the centromeric regions of certain chromosome pairs in two species supports the hypothesis of chromosomal fusions or inversions in the ancestral karyotype of Trypoxylon. The study expands the chromosomal mapping data of repetitive sequences in wasps and offers insights into the dynamic evolutionary landscape of karyotypes in these insects.


Subject(s)
Karyotype , Repetitive Sequences, Nucleic Acid , Telomere , Wasps , Animals , Telomere/genetics , Wasps/genetics , Wasps/classification , Chromosomes, Insect/genetics , Heterochromatin/genetics , In Situ Hybridization, Fluorescence , Evolution, Molecular , Microsatellite Repeats , Karyotyping
3.
Bull Entomol Res ; 114(3): 433-443, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38711293

ABSTRACT

Aphidius colemani is an important biological control agent, used in greenhouses and open fields against aphid pests. Despite this economical importance, A. colemani, along with A. transcaspicus and A. platensis, has gone through a complex taxonomical history. The three species have only recently gained status as separate species again, comprising the morphologically defined Aphidius colemani species group. Other than sporadic records probably as a consequence of escape from greenhouses, the A. colemani species group members prefer warmer regions and there are numerous records from South America, Southern Europe and Asia. Based on slide-mounted material collected in the period 1964-2001 in Africa, we describe five new species belonging to this group, and report A. colemani, A. transcaspicus and A. platensis from several African countries. This data opens questions about the origin of the group and presents potential for the diversification of biological control agents against aphid pests.


Subject(s)
Wasps , Animals , Wasps/classification , Wasps/physiology , Wasps/anatomy & histology , Female , Male , Biodiversity , Pest Control, Biological , Africa , Aphids
4.
Syst Parasitol ; 101(4): 44, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38839661

ABSTRACT

Species of Diolcogaster parasitize Lepidoptera pests of commercial plants. The diversity of this genus is high, but few species of Diolcogaster have been described. The description of a new Diolcogaster species provides information for the biological control using this insect. This study presents the description and key notes on the biology of a new Diolcogaster parasitoid wasp. This species was reared from a caterpillar of Hypercompe brasiliensis collected after feeding on a Gloxinia perennis plant important to floriculture. Two complementary identification analyzes were performed on Diolcogaster adult bodies. The first was the analyses of its external morphology and the second its molecular analysis (mitochondrial DNA). The morphological analysis defined the insect as a new species of Diolcogaster, named Diolcogaster joanesi sp. nov. A maximum-likelihood (ML) analysis partially confirmed the morphological analysis, placing D. joanesi within a cluster including a previously identified species (Diolcogaster choi) and seven other morphospecies. The proximity of D. joanesi to D. choi is discussed and an updated key for all New World species of the xanthaspis group is provided. Twenty-eight adult wasps were obtained (22 females and six males) out of 50 cocoons which larvae emerged from the caterpillar host. The findings contribute to the broader understanding of Diolcogaster in the Neotropics and its potential for the biological control of lepidopteran defoliators.


Subject(s)
Pest Control, Biological , Species Specificity , Wasps , Animals , Brazil , Wasps/classification , Wasps/anatomy & histology , Moths/parasitology , Lepidoptera/parasitology , Phylogeny , Larva , Female
5.
J Virol ; 96(5): e0157321, 2022 03 09.
Article in English | MEDLINE | ID: mdl-34985997

ABSTRACT

Bracoviruses (BVs) are endogenized nudiviruses in parasitoid wasps of the microgastroid complex (family Braconidae). Microgastroid wasps have coopted nudivirus genes to produce replication-defective virions that females use to transfer virulence genes to parasitized hosts. The microgastroid complex further consists of six subfamilies and ∼50,000 species but current understanding of BV gene inventories and organization primarily derives from analysis of two wasp species in the subfamily Microgastrinae (Microplitis demolitor and Cotesia congregata) that produce M. demolitor BV (MdBV) and C. congregata BV (CcBV). Notably, several genomic features of MdBV and CcBV remain conserved since divergence of M. demolitor and C. congregata ∼53 million years ago (MYA). However, it is unknown whether these conserved traits more broadly reflect BV evolution, because no complete genomes exist for any microgastroid wasps outside the Microgastrinae. In this regard, the subfamily Cheloninae is of greatest interest because it diverged earliest from the Microgastrinae (∼85 MYA) after endogenization of the nudivirus ancestor. Here, we present the complete genome of Chelonus insularis, which is an egg-larval parasitoid in the Cheloninae that produces C. insularis BV (CinsBV). We report that the inventory of nudivirus genes in C. insularis is conserved but are dissimilarly organized compared to M. demolitor and C. congregata. Reciprocally, CinsBV proviral segments share organizational features with MdBV and CcBV but virulence gene inventories exhibit almost no overlap. Altogether, our results point to the functional importance of a conserved inventory of nudivirus genes and a dynamic set of virulence genes for the successful parasitism of hosts. Our results also suggest organizational features previously identified in MdBV and CcBV are likely not essential for BV virion formation. IMPORTANCE Bracoviruses are a remarkable example of virus endogenization, because large sets of genes from a nudivirus ancestor continue to produce virions that thousands of wasp species rely upon to parasitize hosts. Understanding how these genes interact and have been coopted by wasps for novel functions is of broad interest in the study of virus evolution. This work characterizes bracovirus genome components in the parasitoid wasp Chelonus insularis, which together with existing wasp genomes captures a large portion of the diversity among wasp species that produce bracoviruses. Results provide new information about how bracovirus genome components are organized in different wasps while also providing additional insights on key features required for function.


Subject(s)
Genome, Insect , Polydnaviridae , Wasps , Animals , Female , Genome Components/genetics , Genome, Insect/genetics , Nudiviridae/genetics , Polydnaviridae/genetics , Polydnaviridae/pathogenicity , Proviruses/genetics , Virulence Factors/genetics , Wasps/classification , Wasps/genetics , Wasps/virology
6.
Cytogenet Genome Res ; 161(3-4): 203-212, 2021.
Article in English | MEDLINE | ID: mdl-33979801

ABSTRACT

Eumeninae represents the largest subfamily within Vespidae, with 3,600 species described. Of these, only 18 have been cytogenetically analysed. In the present study, we used both classical and molecular techniques to characterise and compare the karyotypes of 3 Eumeninae species, namely, Ancistrocerus sp., Pachodynerus grandis, and Pachodynerus nasidens. Ancistrocerus sp. presented a haploid chromosome number of n = 12, with the first 2 chromosomes of the karyotype being almost entirely heterochromatic and much larger than the remaining chromosomes. The 2 Pachodynerus species presented the same chromosome number (n = 11 and 2n = 22) but displayed different karyotypic formulae. Additionally, chromosomal polymorphisms were observed in the analysed P. nasidens female. In the 3 species, heterochromatin was located in one of the chromosome arms. Fluorochrome staining revealed a balanced composition of AT and GC bases within the chromatin for each of the 3 species, except for few regions that were visibly GC-rich. All species had a single 18S rDNA site that co-localised with GC-rich regions; however, this localisation varied from species to species and not all GC-rich regions corresponded to ribosomal genes. Based on the cytogenetic data obtained here, we discuss the possible numerical/structural rearrangements that may be involved in the karyotypic evolution of the 3 studied species. In addition to the first description of the molecular cytogenetic characteristics of the Eumeninae subfamily and the genus Pachodynerus, this study also provides a relevant contribution towards the discussion of chromosomal evolution in Eumeninae wasps.


Subject(s)
Chromosomes, Insect/genetics , Cytogenetic Analysis/methods , RNA, Ribosomal, 18S/genetics , Wasps/genetics , Animals , Chromosome Banding , Female , Heterochromatin/genetics , In Situ Hybridization, Fluorescence/methods , Karyotype , Male , Species Specificity , Wasps/classification
7.
Mol Phylogenet Evol ; 159: 107119, 2021 06.
Article in English | MEDLINE | ID: mdl-33609704

ABSTRACT

The stinging wasps (Hymenoptera: Aculeata) include diverse groups such as vespid wasps, ants and bees. Phylogenetic relationships among major lineages of stinging wasps have been inferred from molecular and morphological data. However, the genomic features of the mitochondrial genomes and their phylogenetic utility remain to be explored. In this study, we determined 23 mitochondrial genomes from the Aculeata. Four Mutillidae species showed relatively low A + T content compared to other species of the Aculeata (69.7%-77.4%). Eleven out of 44 species, mainly from the Chrysididae and the Pompilidae, showed reversals of GC skews. Gene rearrangements occurred across the species. Patterns of tRNA rearrangement were conserved in some groups, including the Chrysididae, Bethylidae, Pompilidae, Scolioidea and Vespoidea. Rearrangement of protein-coding genes were found in 12 out of 44 species of the Aculeata, including all four species from the Chrysididae, both species from the Bethylidae, one species from the Dryinidae, all three Scolioidea species and two Apoidea species. Phylogenetic inference showed a long branch in species with unusual genomic features, such as in the Mutillidae and Bethylidae. By excluding these species, we found paraphyly of the Chrysidoidea and a sister group relationship between the Formicoidea and Vespoidea. These results improve our understanding of the evolution of mitochondrial genomes in the Aculeata and, in general, the evolution across this subclade.


Subject(s)
Gene Rearrangement , Genome, Mitochondrial , Phylogeny , Wasps/classification , Animals , Biological Evolution , Genomics
8.
Genome ; 64(3): 253-264, 2021 Mar.
Article in English | MEDLINE | ID: mdl-32413273

ABSTRACT

Gasteruptiidae Ashmead is an easily recognised family of wasps with ∼589 described species worldwide. Although well characterised by traditional taxonomy, multiple authors have commented on the extreme morphological uniformity of the group, making species-level identification difficult. This problem is enhanced by the lack of molecular data and molecular phylogenetic research for the group. We used 187 cytochrome c oxidase subunit I (COI) barcodes to explore the efficiency of sequence data to delimitate species in Gasteruptiidae. We undertook a graphical and discussion-based comparison of six methods for species delimitation, with the success of methods judged based on known species boundaries and morphology. Both distance-based (ABGD and jMOTU threshold analysis) and tree-based (GMYC and PTP) methods compared across multiple parameters recovered variable molecular operational taxonomic units (MOTUs), ranging from 55 to 123 MOTUs. Tree-based methods tended to split known morphological species less than distance-based methods, with the single-threshold GMYC method the most concordant with known morphospecies. Our results suggest that the incorporation of molecular species delimitation techniques provides a powerful tool to assist in the interpretation of species and help direct informed decisions with taxonomic uncertainty in the family.


Subject(s)
DNA Barcoding, Taxonomic , Wasps/classification , Animals , Genetic Variation , Phylogeny , Wasps/genetics
9.
Genome ; 64(5): 581-590, 2021 May.
Article in English | MEDLINE | ID: mdl-33170730

ABSTRACT

Globally, biodiversity is declining because of anthropogenic pressures, and this could lead to extinction of some species before they are discovered. The loss of insect taxa is of prime concern, given recent reports of significant declines in the populations of many taxa across the globe. Efforts to document biodiversity have met with several challenges, amongst which are the difficulties in using morphological features to discriminate species, especially in insects. DNA barcoding is a rapid and reliable method for species identification and discovery but choosing appropriate primers to amplify the barcode region without co-amplifying contaminants remains a key challenge. We developed and tested a set of primers for PCR amplification of the DNA barcode region of the COI gene in polistine wasps. We tested their efficacy in 36 species of vespid wasps, and the solitary wasp Zethus miniatus Saussure. Samples were obtained from Africa, Americas, Asia, and Europe. The polistine-specific primers successfully amplified the barcode region for all polistines tested, without amplifying any Wolbachia present; they also worked with many species from the other Vespidae wasp subfamilies. The new primers are valuable for the discovery and accurate documentation of polistine wasps in the four continents.


Subject(s)
DNA Barcoding, Taxonomic/methods , DNA Primers , Pest Control , Wasps/genetics , Animals , Biodiversity , DNA/analysis , Insecta/genetics , Phylogeny , Polymerase Chain Reaction , Wasps/classification
10.
BMC Genomics ; 21(1): 427, 2020 Jun 24.
Article in English | MEDLINE | ID: mdl-32580761

ABSTRACT

BACKGROUND: Vespa velutina, one of the most aggressive and fearful wasps in China, can cause grievous allergies and toxic reactions, leading to organ failure and even death. However, there is little evidence on molecular data regarding wasps. Therefore, we aimed to provide an insight into the transcripts expressed in the venom gland of wasps. RESULTS: In our study, high-throughput RNA sequencing was performed using the venom glands of four wasp species. First, the mitochondrial cytochrome C oxidase submit I (COI) barcoding and the neighbor joining (NJ) tree were used to validate the unique identity and lineage of each individual species. After sequencing, a total of 127,630 contigs were generated and 98,716 coding domain sequences (CDS) were predicted from the four species. The Gene ontology (GO) enrichment analysis of unigenes revealed their functional role in important biological processes (BP), molecular functions (MF) and cellular components (CC). In addition, c-type, p1 type, p2 type and p3 type were the most commonly found simple sequence repeat (SSR) types in the four species of wasp transcriptome. There were differences in the distribution of SSRs and single nucleotide polymorphisms (SNPs) among the four wasp species. CONCLUSIONS: The transcriptome data generated in this study will improve our understanding on bioactive proteins and venom-related genes in wasp venom gland and provide a basis for pests control and other applications. To our knowledge, this is the first study on the identification of large-scale genomic data and the discovery of microsatellite markers from V. tropica ducalis and V. analis fabricius.


Subject(s)
Gene Expression Profiling/veterinary , Genetic Markers , Insect Proteins/genetics , Wasp Venoms/genetics , Wasps/classification , Animals , Evolution, Molecular , Gene Ontology , High-Throughput Nucleotide Sequencing , Microsatellite Repeats , Molecular Sequence Annotation , Phylogeny , Polymorphism, Single Nucleotide , Sequence Analysis, RNA , Wasps/genetics
11.
Am Nat ; 195(2): 181-191, 2020 02.
Article in English | MEDLINE | ID: mdl-32017631

ABSTRACT

Insect flight is made possible by different morphological structures: wings produce the lift, the thorax drives the wings' movements, and the abdomen serves as a secondary control device. As such, the covariation of these structures could reflect functional constraints related to flight performances. This study examines evolutionary convergences in wasp body shapes to provide the first evidence for morphological integration among insect wings, thorax, and abdomen. The shapes of the forewings and hind wings, thorax, and petiole (connecting abdomen and thorax) of 22 Vespidae species were analyzed using computerized tomography and geometric morphometrics. Results show a clear relationship between petiole and wings or thorax shapes but not between wings and thorax. Wasps with elongated bodies have pointed wings, both features thought to improve flight maneuverability. In contrast, stouter species have rounded wings, which may allow for higher flight speeds. These integration patterns suggest that multiple selective regimes on flight performance, some of them biased toward maneuverability or maximal speed, drove the morphological diversity in Vespidae. The results also suggest that wing shapes evolved under constraints related to the body type they have to lift. The abdomen morphology is thus another factor to take into account to understand the flight performance of insects.


Subject(s)
Biological Evolution , Wasps/anatomy & histology , Wings, Animal/anatomy & histology , Animals , Female , Flight, Animal , Thorax/anatomy & histology , Wasps/classification
12.
Cytogenet Genome Res ; 160(11-12): 711-718, 2020.
Article in English | MEDLINE | ID: mdl-33752199

ABSTRACT

The characterization of karyotypes is an important aspect in understanding the structure and evolution of genomes. Polybia is a genus of social wasps of the family Vespidae. This genus has 58 species, but for only 8 of these chromosome number and morphology have been reported in the literature. The aim of this study was to describe and characterize the Polybia fastidiosuscula Saussure karyotype, presenting the first case of a B chromosome in Vespidae. In addition, we investigated the chromatin composition of this species through C-banding, base-specific fluorochrome staining, and physical mapping of 7 microsatellites and 18S rDNA. Four colonies of P. fastidiosuscula from Minas Gerais and Paraná states, Brazil, were analyzed. The chromosome number identified was 2n = 34, and 2 colonies presented a B chromosome. We characterized the chromatin composition of this species, analyzing the existence of different microsatellite-rich heterochromatic regions which are also enriched with AT or GC base pairs. We suggest an intraspecific origin of the B chromosome based on the homology of the heterochromatic composition with A chromosomes and also verify that the TTAGG and TCAGG sequences are not telomeric, but only microsatellites that occur in the centromeres of most chromosomes, as well as GAG and CGG.


Subject(s)
Chromatin/genetics , Chromosomes, Insect/genetics , Karyotype , Microsatellite Repeats/genetics , Wasps/genetics , Animals , Base Pairing , Base Sequence , Brazil , Chromosome Banding , Female , RNA, Ribosomal, 18S/genetics , Wasps/classification
13.
Mol Phylogenet Evol ; 153: 106949, 2020 12.
Article in English | MEDLINE | ID: mdl-32866614

ABSTRACT

Gall wasps in the genus Diplolepis Geoffroy are specialized herbivores that induce galls exclusively on roses. Despite their wide distribution across the Holarctic, little is known about their evolutionary history. Here we present the first phylogenomic tree of global Diplolepis reconstructed using Ultraconserved Elements (UCEs), resulting in a robust phylogeny based on 757 genes. Results support the existence of two principal clades: a Nearctic stem-galler clade, and a Holarctic leaf-galler clade that further splits into two Palearctic groups and one Nearctic group. This topology is congruent with a previous study based on the mitochondrial gene COI, an unexpected result given the common occurrence of mitonuclear discordance in closely related oak gall wasp lineages. Most Diplolepis species were recovered as reciprocally monophyletic, with some notable exceptions such as the D. polita and the D. ignota complex, for which species boundaries remain unresolved. Historical biogeographic reconstruction was unable to pinpoint the origin of Diplolepis, but confirms two independent incursions into the Nearctic. Ancestral state reconstruction analysis highlights the conservatism of gall location on the host plants, as shifts to different host organs are relatively rare. We suggest that Diplolepis were originally leaf gallers, with a Nearctic stem-galler clade undergoing a major plant organ switch onto rose stems. Host organ switch or reversal is uncommon, which suggests a level of conservatism. Our study showcases the resolving power of UCEs at the species level while also suggesting improvements to advance future Cynipoidea phylogenomics. Our results also highlight the additional sampling needed to clarify taxonomic relationships in the Nearctic and eastern Palearctic regions.


Subject(s)
Phylogeny , Wasps/classification , Wasps/genetics , Animals , Conserved Sequence/genetics , Genes, Mitochondrial/genetics , North America , Rosa/parasitology
14.
Article in English | MEDLINE | ID: mdl-32920209

ABSTRACT

Climate change is expected to produce shifts in species distributions as well as behavioural and physiological adaptations to find suitable conditions or to cope with the altered environment. The paper wasps Polistes dominula and Polistes gallicus are closely related species, native in the European Mediterranean region and North Africa. P. dominula has expanded its range to the relatively cooler climates of Northern and Eastern Europe, but P. gallicus remained in its original distribution area. In order to reveal their metabolic adaptation to the current climate conditions, and the impact on energy demand at future climate conditions, we investigated the respiratory metabolic rate (CO2 production) of P. dominula from Austria and P. gallicus from Italy. In contrast to the metabolic cold adaptation hypothesis their standard metabolic rate was nearly the same and increased in a typical exponential course with increasing ambient temperature. The metabolic rate of active wasps was higher than the standard metabolic rate and increased with the wasps' activity. There was no obvious difference in the active metabolism between the two species, with the exception that some P. gallicus individuals showed some extraordinary high values. A simultaneous measurement of metabolic rate and body temperature revealed that increased CO2 production was accompanied by endothermic activity. The two investigated populations of paper wasps are quite similar in their metabolic response to temperature, although they live in different climate regions. The spread of P. dominula into cooler regions did not have significant influence on their active and standard metabolic rate.


Subject(s)
Wasps/physiology , Animals , Body Temperature , Carbon Dioxide/metabolism , Respiration , Species Specificity , Wasps/classification , Wasps/metabolism
15.
Annu Rev Entomol ; 64: 335-358, 2019 01 07.
Article in English | MEDLINE | ID: mdl-30332295

ABSTRACT

The parasitoid wasp family Braconidae is likely the second-most species-rich family in the animal kingdom. Braconid wasps are widely distributed and often encountered. They constitute one of the principal groups of natural enemies of phytophagous insects, of which many are serious pest species. The enormous biological diversification of braconid wasps has led to many homoplasies, which contributed widely to instabilities in historical classifications. Recent studies using combinations of genetic markers or total mitochondrial genomes allow for better founded groupings and will ultimately lead to a stable classification. We present the current status of the phylogenetics of the Braconidae in a historical perspective and our understanding of the effects on higher classification.


Subject(s)
Phylogeny , Wasps/genetics , Animals , Geography , Wasps/classification
16.
BMC Genomics ; 20(1): 893, 2019 Nov 21.
Article in English | MEDLINE | ID: mdl-31752718

ABSTRACT

BACKGROUND: Parasitic insects are well-known biological control agents for arthropod pests worldwide. They are capable of regulating their host's physiology, development and behaviour. However, many of the molecular mechanisms involved in host-parasitoid interaction remain unknown. RESULTS: We sequenced the genomes of two parasitic wasps (Cotesia vestalis, and Diadromus collaris) that parasitize the diamondback moth Plutella xylostella using Illumina and Pacbio sequencing platforms. Genome assembly using SOAPdenovo produced a 178 Mb draft genome for C. vestalis and a 399 Mb draft genome for D. collaris. A total set that contained 11,278 and 15,328 protein-coding genes for C. vestalis and D. collaris, respectively, were predicted using evidence (homology-based and transcriptome-based) and de novo prediction methodology. Phylogenetic analysis showed that the braconid C. vestalis and the ichneumonid D. collaris diverged approximately 124 million years ago. These two wasps exhibit gene gains and losses that in some cases reflect their shared life history as parasitic wasps and in other cases are unique to particular species. Gene families with functions in development, nutrient acquisition from hosts, and metabolism have expanded in each wasp species, while genes required for biosynthesis of some amino acids and steroids have been lost, since these nutrients can be directly obtained from the host. Both wasp species encode a relative higher number of neprilysins (NEPs) thus far reported in arthropod genomes while several genes encoding immune-related proteins and detoxification enzymes were lost in both wasp genomes. CONCLUSIONS: We present the annotated genome sequence of two parasitic wasps C. vestalis and D. collaris, which parasitize a common host, the diamondback moth, P. xylostella. These data will provide a fundamental source for studying the mechanism of host control and will be used in parasitoid comparative genomics to study the origin and diversification of the parasitic lifestyle.


Subject(s)
Genome, Insect , Moths/parasitology , Wasps/genetics , Animals , Genes, Insect , Immunity/genetics , Multigene Family , Phylogeny , Wasps/classification
17.
Proc Biol Sci ; 286(1895): 20182352, 2019 01 30.
Article in English | MEDLINE | ID: mdl-30963952

ABSTRACT

Understanding phenotypic diversification and the conditions that spur morphological novelty or constraint is a major theme in evolutionary biology. Unequal morphological diversity between sister clades can result from either differences in the rate of morphological change or in the ability of clades to explore novel phenotype ranges. We combine an existing phylogenetic framework with new phylogenomic data and geometric morphometrics to explore the relative roles of rate versus mode of morphological evolution for a hyperdiverse group: cryptine ichneumonid wasps. Data from genomic ultraconserved elements confirm that cryptines are divided into two large clades: one specialized in the use of hosts that are deeply concealed under hard substrates, and another with a much more diversified host range. Using a phylomorphospace approach, we show that both clades have experienced similar rates of morphological evolution. Nonetheless, the more specialized group is much more restricted in morphospace occupation, indicating that it repeatedly evolved morphological change through the same morphospace regions. This is in agreement with our prediction that host use imposes constraints in the morphospace available to lineages, and reinforces an important distinction between evolutionary stasis as opposed to a scenario of continual morphological change restricted to a certain range of morphotypes.


Subject(s)
Biological Evolution , Environment , Host-Parasite Interactions , Wasps/anatomy & histology , Animals , Phylogeny , Wasps/classification , Wasps/genetics
18.
Insect Mol Biol ; 28(4): 485-498, 2019 08.
Article in English | MEDLINE | ID: mdl-30632223

ABSTRACT

A recent DNA barcoding study of Australian microgastrines (Hymenoptera: Braconidae) sought to use next-generation sequencing of the cytochrome c oxidase subunit 1 (COI) barcoding gene region, the wingless (WG) gene and the internal transcribed spacer 2 (ITS2) to delimit molecular species in a highly diverse group of parasitic wasps. Large intragenomic distances between ITS2 variants, often larger than the average interspecific variation, caused difficulties in using ITS2 for species delimitation in both threshold and tree-based approaches, and the gene was not included in the reported results of the previous DNA barcoding study. We here report on the intragenomic, and the intra- and interspecies, variation in ITS2in the microgastrine genus Diolcogasterto further investigate the value of ITS2as a marker for species delimitation and phylogenetics of the Microgastrinae. Distinctive intragenomic variant patterns were found in different species of Diolcogaster, with some species possessing a single major variant, and others possessing many divergent variants. Characterizing intragenomic variation of ITS2is critical as it is a widely used marker in hymenopteran phylogenetics and species delimitation, and large intragenomic distances such as those found in this study may obscure phylogenetic signal.


Subject(s)
DNA Barcoding, Taxonomic , DNA, Ribosomal Spacer/analysis , Phylogeny , Wasps/classification , Animals , Insect Proteins/analysis , Polymerase Chain Reaction/methods , Sequence Analysis, DNA , Wasps/genetics
19.
PLoS Biol ; 14(7): e1002500, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27380029

ABSTRACT

Gene expression divergence between closely related species could be attributed to both cis- and trans- DNA sequence changes during evolution, but it is unclear how the evolutionary dynamics of epigenetic marks are regulated. In eutherian mammals, biparental DNA methylation marks are erased and reset during gametogenesis, resulting in paternal or maternal imprints, which lead to genomic imprinting. Whether DNA methylation reprogramming exists in insects is not known. Wasps of the genus Nasonia are non-social parasitoids that are emerging as a model for studies of epigenetic processes in insects. In this study, we quantified allele-specific expression and methylation genome-wide in Nasonia vitripennis and Nasonia giraulti and their reciprocal F1 hybrids. No parent-of-origin effect in allelic expression was found for >8,000 covered genes, suggesting a lack of genomic imprinting in adult Nasonia. As we expected, both significant cis- and trans- effects are responsible for the expression divergence between N. vitripennis and N. giraulti. Surprisingly, all 178 differentially methylated genes are also differentially methylated between the two alleles in F1 hybrid offspring, recapitulating the parental methylation status with nearly 100% fidelity, indicating the presence of strong cis-elements driving the target of gene body methylation. In addition, we discovered that total and allele-specific expression are positively correlated with allele-specific methylation in a subset of the differentially methylated genes. The 100% cis-regulation in F1 hybrids suggests the methylation machinery is conserved and DNA methylation is targeted by cis features in Nasonia. The lack of genomic imprinting and parent-of-origin differentially methylated regions in Nasonia, together with the stable inheritance of methylation status between generations, suggests either a cis-regulatory motif for methylation at the DNA level or highly stable inheritance of an epigenetic signal in Nasonia.


Subject(s)
DNA Methylation , Epigenesis, Genetic , Inheritance Patterns/genetics , Transcriptome , Wasps/genetics , Alleles , Animals , CpG Islands/genetics , Evolution, Molecular , Female , Genes, Insect/genetics , Genome, Insect/genetics , Hybridization, Genetic , Male , Polymorphism, Single Nucleotide , Species Specificity , Wasps/classification
20.
Genome ; 62(3): 183-199, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30365918

ABSTRACT

Wild and cultivated olives harbor and share a diversity of insects, some of which are considered agricultural pests, such as the olive fruit fly. The assemblage of olive-associated parasitoids and seed wasps is rich and specialized in sub-Saharan Africa, with native species possibly coevolving with their hosts. Although historical entomological surveys reported on the diversity of olive wasp species in the Western Cape Province of South Africa, no comprehensive study has been performed in the region in the molecular era. In this study, a dual approach combining morphological and DNA-based methods was used for the identification of adult specimens reared from olive fruits. Four species of Braconidae and six species of Chalcidoidea were identified, and DNA barcoding methodologies were used to investigate conspecificity among individuals, based on randomly selected representative specimens. Morphological identifications were congruent with DNA data, as NJ and ML trees correctly placed the sequences for each species either at the genus or species level, depending on the available taxa coverage, and genetic distances strongly supported conspecificity. No clear evidence of cryptic diversity was found. Overall seed infestation and parasitism rates were higher in wild olives compared to cultivated olives, and highest for Eupelmus spermophilus and Utetes africanus. These results can be used for early DNA-based detection of wasp larvae in olives and to further investigate the biology and ecology of these species.


Subject(s)
Biodiversity , DNA Barcoding, Taxonomic/methods , DNA/genetics , Olea/parasitology , Wasps/classification , Wasps/genetics , Animals , DNA/analysis , Olea/genetics , Phylogeny , South Africa
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