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1.
Sheng Wu Gong Cheng Xue Bao ; 39(12): 4996-5013, 2023 Dec 25.
Artigo em Chinês | MEDLINE | ID: mdl-38147997

RESUMO

Transmembrane emp24 domain (TMED) gene is closely related to immune response, signal transduction, growth and disease development in mammals. However, only the Drosophila TMED gene has been reported on insects. We identified the TMED family genes of silkworm, Tribolium castaneum, tobacco moth and Italian bee from their genomes, and found that the TMED family gene composition patterns of one α-class, one ß-class, one δ-class and several γ-classes arose in the common ancestor of pre-divergent Hymenoptera insects, while the composition of Drosophila TMED family members has evolved in a unique pattern. Insect TMED family γ-class genes have evolved rapidly, diverging into three separate subclasses, TMED6-like, TMED5-like and TMED3-like. The TMED5-like gene was lost in Hymenoptera, duplicated in the ancestors of Lepidoptera and duplicated in Drosophila. Insect TMED protein not only has typical structural characteristics of TMED, but also has obvious signal peptide. There are seven TMED genes in silkworm, distributed in six chromosomes. One of seven is single exon and others are multi-exons. The complete open reading frame (ORF) sequences of seven TMED genes of silkworm were cloned from larval tissues and registered in GenBank database. BmTMED1, BmTMED2 and BmTMED6 were expressed in all stages and tissues of the silkworm, and all genes were expressed in the 4th and 5th instar and silk gland of the silkworm. The present study revealed the composition pattern of TMED family members, their γ class differentiation and their evolutionary history, providing a basis for further studies on TMED genes in silkworm and other insects.


Assuntos
Bombyx , Mariposas , Animais , Bombyx/genética , Bombyx/metabolismo , Genes de Insetos/genética , Mariposas/genética , Mariposas/metabolismo , Insetos/genética , Insetos/metabolismo , Drosophila , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Filogenia , Mamíferos/genética
2.
Zootaxa ; 5315(3): 251-263, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37518604

RESUMO

The name Striatochrista nom. n. is introduced as replacement for Striatella Volynkin & S.-Y. Huang, 2019. A new genus, Letrasilta S.-Y. Huang & Volynkin gen. n. is erected to include the Striatella cernyi species-group with the new species, L. ratnasambhava S.-Y. Huang, Volynkin & Yin sp. n. from Xizang, southwestern China designated as the type species. Based on the molecular phylogenetic analysis, the new genus is found to be sister to the clade (Aberrasine + ((Indiania + Idopterum) + Striatochrista nom. n.)) but is distinguished from all the relevant genera by the unique genitalia features. Letrasilta cernyi (Volynkin, 2018) comb. n. is also reported from India for the first time. Adults and genitalia of the aforementioned taxa are illustrated. A checklist of the genus Striatochrista is also provided.


Assuntos
Mariposas , Filogenia , Animais , China , Genitália/anatomia & histologia , Mariposas/anatomia & histologia , Mariposas/classificação , Mariposas/genética , Genes de Insetos/genética , Especificidade da Espécie
3.
Zootaxa ; 5254(3): 357-369, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-37044717

RESUMO

Recent survey efforts in Costa Rica have documented many new species of planthoppers, primarily in the families Derbidae and Cixiidae, on palms. Recently, a specimen was collected sweeping palms in the Los Angeles cloud forest in Costa Rica and was identified as belonging to the genus Herpis (Derbidae). It was subsequently determined to represent a previously undescribed species. Herein, the new species, Herpis circumsoros Bahder & Bartlett sp. n. is described with supplemental molecular data for the cytochrome c oxidase subunit I (COI) gene and 18S rRNA gene to support placement of the new species in the genus Herpis.


Assuntos
Hemípteros , Animais , Arecaceae , Costa Rica , Florestas , Hemípteros/anatomia & histologia , Hemípteros/classificação , Hemípteros/genética , Genes de Insetos/genética
4.
PLoS One ; 17(7): e0270840, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35797274

RESUMO

Bombyx mori is an important economic insect, its economic value mainly reflected in the silk yield. The major functional genes affecting the silk yield of B. mori have not been determined yet. Bombyx mori vacuolar protein sorting-associated protein 13d (BmVps13d) has been identified, but its function is not reported. In this study, BmVps13d protein shared 30.84% and 34.35% identity with that of in Drosophila melanogaster and Homo. sapiens, respectively. The expressions of BmVps13d were significantly higher in the midgut and silk gland of JS (high silk yield) than in that of L10 (low silk yield). An insertion of 9 bp nucleotides and two deficiencies of adenine ribonucleotides in the putative promoter region of BmVps13d gene in L10 resulted in the decline of promoter activity was confirmed using dual luciferase assay. Finally, the functions of BmVps13d in B. mori were studied using the CRISPR/Cas9 system, and the mutation of BmVps13d resulted in a 24.7% decline in weight of larvae, as well as a 27.1% (female) decline and a 11.8% (male) decline in the silk yield. This study provides a foundation for studying the molecular mechanism of silk yield and breeding the silkworm with high silk yield.


Assuntos
Bombyx , Genes de Insetos , Proteínas de Insetos , Seda , Animais , Bombyx/química , Bombyx/genética , Bombyx/metabolismo , Proteínas de Drosophila , Drosophila melanogaster/química , Feminino , Genes de Insetos/genética , Humanos , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Larva/anatomia & histologia , Masculino , Mutação , Regiões Promotoras Genéticas/genética , Proteínas , Seda/biossíntese
5.
Nat Commun ; 13(1): 755, 2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35136048

RESUMO

Seasonal plasticity is accomplished via tightly regulated developmental cascades that translate environmental cues into trait changes. Little is known about how alternative splicing and other posttranscriptional molecular mechanisms contribute to plasticity or how these mechanisms impact how plasticity evolves. Here, we use transcriptomic and genomic data from the butterfly Bicyclus anynana, a model system for seasonal plasticity, to compare the extent of differential expression and splicing and test how these axes of transcriptional plasticity differ in their potential for evolutionary change. Between seasonal morphs, we find that differential splicing affects a smaller but functionally unique set of genes compared to differential expression. Further, we find strong support for the novel hypothesis that spliced genes are more susceptible than differentially expressed genes to erosion of genetic variation due to selection on seasonal plasticity. Our results suggest that splicing plasticity is especially likely to experience genetic constraints that could affect the potential of wild populations to respond to rapidly changing environments.


Assuntos
Adaptação Fisiológica/genética , Processamento Alternativo , Borboletas/fisiologia , Genes de Insetos/genética , Estágios do Ciclo de Vida/genética , Animais , Evolução Biológica , Feminino , Variação Genética , Modelos Genéticos , Estações do Ano , Transcrição Gênica
6.
Genes (Basel) ; 12(12)2021 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-34946836

RESUMO

The German cockroach, Blattella germanica, and the American cockroach, Periplaneta americana are the most common and synanthropic household pests of interest to public health. While they have increasingly served as model systems in hemimetabolous insects for studying many biological issues, there is still a lack of stable reference gene evaluation for reliable quantitative real-time PCR (qPCR) outputs and functional genomics. Here, we evaluated the expression variation of common insect reference genes, including the historically used actin, across various tissues and developmental stages, and also under experimental treatment conditions in these two species by using three individual algorithms (geNorm, BestKeeper, and NormFinder) and a comprehensive program (RefFinder). RPL32 in B. germanica and EF1α in P. americana showed the overall lowest variation among all examined samples. Based on the stability rankings by RefFinder, the optimal but varied reference genes under specific conditions were selected for qPCR normalization. In addition, the combination of RPL32 and EF1α was recommended for all the tested tissues and stages in B. germanica, whereas the combination of multiple reference genes was unfavorable in P. americana. This study provides a condition-specific resource of reference gene selection for accurate gene expression profiling and facilitating functional genomics in these two important cockroaches.


Assuntos
Blattellidae/genética , Genes de Insetos/genética , Transcrição Gênica/genética , Animais , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Genômica/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Padrões de Referência , Seleção Genética/genética
7.
Genes (Basel) ; 12(12)2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34946935

RESUMO

Kapok is the main host of Glenea cantor (Fabricius), which causes serious damage and is difficult to control. In severe cases, it often causes the kapok trees to die continuously, which seriously affects the results of urban landscaping. To provide reference for the functional research on related genes in G. cantor, we screened the stable expression of candidate reference genes at different developmental stages (i.e., eggs, larvae, pupae, and adults), in various adult tissues (i.e., head, thorax, abdomen, feet, antennae, and wings), and sexes (i.e., male pupae, female pupae, male adults, and female adults). In this study, 12 candidate reference genes (i.e., ACTINLIKE, ACTININ, TUB, RPL36, RPL32, RPS20, TBP, GAPDH, 18S rRNA, EF1A1, EF1A2, and UBQ) were evaluated using different adult tissues, developmental stages, and sexes. RefFinder, geNorm, NormFinder, and BestKeeper were used to evaluate and comprehensively analyze the stability of the expression of the candidate reference genes. The results show that RPL32 and EF1A1 were the most suitable reference genes in the different adult tissues, and RPL36 and EF1A1 were best at the different developmental stages. RPL36 and EF1A2 were the best fit for the qRT-PCR reference genes in the different sexes, while RPL36 and EF1A1 were the most appropriate qRT-PCR reference genes in all samples. Results from geNorm showed that the optimal number of reference genes was two. We also surveyed the expression of cellulase at the different developmental stages and in the different adult tissues. Results further verified the reliability of the reference genes, and confirmed the best reference genes under the different experimental conditions. This study provides a useful tool for molecular biological studies on G. cantor.


Assuntos
Besouros/genética , Genes de Insetos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Transcriptoma/genética , Animais , China , Perfilação da Expressão Gênica/métodos , Larva/genética , Pupa/genética , Padrões de Referência , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
8.
Genetics ; 219(3)2021 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-34740249

RESUMO

In most experimental animals, it is challenging to combine mutations and rescue transgenes and to use bipartite systems to assess gene expression. To circumvent the difficulties in combining multiple genetic elements, we developed the DREaMR (Drug-on, REporter, Mutant, Rescue) system. Using Drosophila white as the initial model, we demonstrated that introduction of a single insertion by CRISPR/Cas9 created a null mutation, a tagged rescue construct, which could be induced with doxycycline, and which allowed assessment of protein expression. To create a DREaMR in an organism in which combining multiple genetic elements is more problematic than in Drosophila, we tested the mosquito, Aedes aegypti-the insect vector for dengue, yellow fever, Zika, and other viral diseases. We generated a DREaMR allele in the kh gene, which permitted us to induce expression of the rescue construct, and detect expression of Kh. Thus, this system avoids the need to perform genetic crosses to introduce an inducible rescue transgene in a mutant background, or to combine driver and reporter lines to examine expression of the targeted protein. We propose that DREaMR provides a system that can be applied to additional mosquito vectors as well as other organisms in which CRISPR/Cas9 is effective.


Assuntos
Aedes/genética , Animais Geneticamente Modificados/genética , Edição de Genes/métodos , Controle de Mosquitos/métodos , Mosquitos Vetores/genética , Animais , Sistemas CRISPR-Cas/genética , Drosophila melanogaster/genética , Genes de Insetos/genética , Mutação
9.
PLoS Genet ; 17(10): e1009792, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34662332

RESUMO

The transformer (tra) gene is essential for female development in many insect species, including the Australian sheep blow fly, Lucilia cuprina. Sex-specific tra RNA splicing is controlled by Sex lethal (Sxl) in Drosophila melanogaster but is auto-regulated in L. cuprina. Sxl also represses X chromosome dosage compensation in female D. melanogaster. We have developed conditional Lctra RNAi knockdown strains using the tet-off system. Four strains did not produce females on diet without tetracycline and could potentially be used for genetic control of L. cuprina. In one strain, which showed both maternal and zygotic tTA expression, most XX transformed males died at the pupal stage. RNAseq and qRT-PCR analyses of mid-stage pupae showed increased expression of X-linked genes in XX individuals. These results suggest that Lctra promotes somatic sexual differentiation and inhibits X chromosome dosage compensation in female L. cuprina. However, XX flies homozygous for a loss-of-function Lctra knockin mutation were fully transformed and showed high pupal eclosion. Two of five X-linked genes examined showed a significant increase in mRNA levels in XX males. The stronger phenotype in the RNAi knockdown strain could indicate that maternal Lctra expression may be essential for initiation of dosage compensation suppression in female embryos.


Assuntos
Compensação de Dosagem (Genética)/genética , Drosophila melanogaster/genética , Genes de Insetos/genética , Animais , Animais Geneticamente Modificados , Austrália , Calliphoridae/genética , Dípteros/genética , Proteínas de Drosophila/genética , Feminino , Genes Ligados ao Cromossomo X/genética , Masculino , Pupa/genética , Interferência de RNA/fisiologia , Splicing de RNA/genética , Proteínas de Ligação a RNA/genética , Ovinos , Fatores de Transcrição/genética , Cromossomo X/genética
10.
Sci Rep ; 11(1): 18269, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521896

RESUMO

Division of labour characterizes all major evolutionary transitions, such as the evolution of eukaryotic cells or multicellular organisms. Social insects are characterized by reproductive division of labour, with one or a few reproducing individuals (queens) and many non-reproducing nestmates (workers) forming a colony. Among the workers, further division of labour can occur with different individuals performing different tasks such as foraging, brood care or building. While mechanisms underlying task division are intensively studied in social Hymenoptera, less is known for termites, which independently evolved eusociality. We investigated molecular mechanisms underlying task division in termite workers to test for communality with social Hymenoptera. We compared similar-aged foraging workers with builders of the fungus-growing termite Macrotermes bellicosus using transcriptomes, endocrine measures and estimators of physiological condition. Based on results for social Hymenoptera and theory, we tested the hypotheses that (i) foragers are in worse physiological conditions than builders, (ii) builders are more similar in their gene expression profile to queens than foragers are, and (iii) builders invest more in anti-ageing mechanism than foragers. Our results support all three hypotheses. We found storage proteins to underlie task division of these similar-aged termite workers and these genes also characterize reproductive division of labour between queens and workers. This implies a co-option of nutrient-based pathways to regulate division of labour across lineages of termites and social Hymenoptera, which are separated by more than 133 million years.


Assuntos
Evolução Molecular , Isópteros/genética , Comportamento Social , Animais , Evolução Biológica , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Genes de Insetos/genética , Isópteros/fisiologia , Masculino , Transcriptoma/genética
11.
Genes (Basel) ; 12(8)2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34440427

RESUMO

Tuta absoluta is one of the most significant invasive pests affecting tomato plants worldwide. RT-qPCR has emerged as one of the most sensitive and accurate methods for detecting gene expression data. The screening of stable internal reference genes is the most critical step for studying the molecular mechanisms of environmental adaptability. The stable reference genes expressed in T. absoluta under specific experimental conditions have not yet been clarified. In this study, seven candidate reference genes (RPL27, RPS13, RPS15, EF1-α, TUB, TBP, and ß-actin) and their optimal numbers were evaluated under biotic (developmental stages and adult tissues) and abiotic (insecticide, temperature, and plant VOC) conditions using four software programs. Our results identified the following reference genes and numbers as optimal: three genes (EF1-α, RPS13, and RPL27) for different developmental stages (egg, larva, pupa, unmated adult), two genes (RPS13 and TBP) for adult tissues (antenna, head, thorax, abdomen, leg), two genes (TBP and RPS13) for insecticides (Bacillus thuringiensis, chlorpyrifos, abamectin-aminomethyl, and chlorantraniliprole), two genes (RPL27 and TUB) for temperature-induced stresses (0, 25, and 40 °C), and two genes (RPS13 and TUB) for VOC-induced stresses (nonanal, α-phellandrene, and tomato leaves). Our results provide a reference for selecting appropriate reference genes for further study of the functional genes of T. absoluta under different experimental conditions.


Assuntos
Genes de Insetos/genética , Lepidópteros/genética , Reação em Cadeia da Polimerase em Tempo Real/normas , Solanum lycopersicum/parasitologia , Animais , Inseticidas/farmacologia , Larva/genética , Larva/patogenicidade , Lepidópteros/patogenicidade , Solanum lycopersicum/genética , Solanum lycopersicum/crescimento & desenvolvimento , Mariposas/genética , Mariposas/patogenicidade , Controle Biológico de Vetores , Padrões de Referência
12.
PLoS One ; 16(6): e0253528, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34153077

RESUMO

The moth pest fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is now present throughout much of the Eastern Hemisphere where it poses a significant economic threat to a number of crops. Native to the Western Hemisphere, fall armyworm is one of the primary pests of corn in the Americas and periodically causes significant economic damage to sorghum, millet, cotton, rice, and forage grasses. This broad host range is in part the result of two populations historically designated as host strains (C-strain and R-strain) that differ in their host plant preferences. Reports of infestations in Africa have to date mostly been limited to the C-strain preferred crops of corn and sorghum, with little evidence of an R-strain presence. However, this could reflect a bias in monitoring intensity, with the R-strain perhaps being more prevalent in other crop systems that have not been as routinely examined for the pest. Because knowledge of whether and to what extent both strains are present is critical to assessments of crops at immediate risk, we analyzed specimens obtained from a systematic survey of pasture grass and rice fields, habitats typically preferred by the R-strain, done contemporaneously with collections from corn fields in Ghana and Togo. Substantial larval infestations were only observed in corn, while pheromone trap capture numbers were high only in corn and rice habitats. Little to no fall armyworm were found in the pasture setting. Comparisons with a meta-analysis of studies from South America identified differences in the pattern of strain-specific markers typically found in fall armyworm collected from rice habitats between the two hemispheres. Genetic tests of specimens from rice and corn area traps failed to show evidence of differential mating between strains. These results are consistent with the R-strain being rare or even absent in Africa and, at least for the Ghana-Togo area, this R-strain lack does not appear to be due to limitations in pest monitoring. The implications of these results to the crops at risk in Africa and the accuracy of existing molecular markers of strain identity are discussed.


Assuntos
Camundongos/parasitologia , Milhetes , Oryza , Spodoptera , Animais , Produção Agrícola , Demografia , Feminino , Genes de Insetos/genética , Gana , Masculino , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , América do Sul , Spodoptera/genética , Togo
13.
Commun Biol ; 4(1): 733, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-34127782

RESUMO

Most of our knowledge of insect genomes comes from Holometabolous species, which undergo complete metamorphosis and have genomes typically under 2 Gb with little signs of DNA methylation. In contrast, Hemimetabolous insects undergo the presumed ancestral process of incomplete metamorphosis, and have larger genomes with high levels of DNA methylation. Hemimetabolous species from the Orthopteran order (grasshoppers and crickets) have some of the largest known insect genomes. What drives the evolution of these unusual insect genome sizes, remains unknown. Here we report the sequencing, assembly and annotation of the 1.66-Gb genome of the Mediterranean field cricket Gryllus bimaculatus, and the annotation of the 1.60-Gb genome of the Hawaiian cricket Laupala kohalensis. We compare these two cricket genomes with those of 14 additional insects and find evidence that hemimetabolous genomes expanded due to transposable element activity. Based on the ratio of observed to expected CpG sites, we find higher conservation and stronger purifying selection of methylated genes than non-methylated genes. Finally, our analysis suggests an expansion of the pickpocket class V gene family in crickets, which we speculate might play a role in the evolution of cricket courtship, including their characteristic chirping.


Assuntos
Evolução Molecular , Genoma de Inseto/genética , Gryllidae/genética , Insetos/genética , Animais , Metilação de DNA , Elementos de DNA Transponíveis/genética , Feminino , Genes de Insetos/genética , Masculino , Filogenia , Sequências Repetitivas de Ácido Nucleico/genética , Análise de Sequência de DNA
14.
Mol Biol Rep ; 48(4): 3155-3163, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33939074

RESUMO

Western flower thrips, Frankliniella occidentalis is an economically important agricultural pest. It causes damage by feeding and oviposition or indirectly by plant virus transmission. Australian F. occidentalis are resistant to many insecticides including spinosad and the related chemical spinetoram. Spinetoram resistance to F. occidentalis has been recently reported in three different Australian States, however, mechanisms conferring that resistance have not been investigated. To identify the mechanisms underlying resistance to spinetoram in F. occidentalis, we sequenced the genomic region of nicotinic acetylcholine receptor Foα6 in number of spinosad and spinetoram resistant field-populations. We found that a single nucleotide substitution (G to A) in exon 9 of the α6 subunit was present in resistant strains (G275E) and absent from susceptible. By examining field populations we consider the G275E mutation is the major cause of resistance to spinetoram in Australian F. occidentalis. We developed a real-time PCR diagnostic assay to quickly identify resistant alleles in field-populations. The method was used to test spinetoram resistant F. occidentalis collected from Australian cotton during the 2018-2019. Results show thrips tested carried the G275E mutation and the resistance allele was unusually widely distributed. The wide distribution of G275E mutation was not expected because spinetoram is not extensively used in Australian cotton. We speculate resistance may relate to extensive chemical use in crops nearby such as horticulture where thrips are often targeted for control. Our molecular diagnostic assay can provide timely and precise resistance frequency information that can support sustainable chemical use including spinetoram based IPM.


Assuntos
Resistência a Inseticidas/genética , Macrolídeos/farmacologia , Receptores Nicotínicos/genética , Tisanópteros , Animais , Austrália , Produtos Agrícolas , Combinação de Medicamentos , Genes de Insetos/genética , Inseticidas/farmacologia , Mutação , Controle de Pragas , Tisanópteros/efeitos dos fármacos , Tisanópteros/genética
15.
Sci Rep ; 11(1): 8334, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33859212

RESUMO

For decades, the American palm weevil (APW), Rhynchophorus palmarum, has been a threat to coconut and oil palm production in the Americas. It has recently spread towards North America, endangering ornamental palms, and the expanding date palm production. Its behavior presents several parallelisms with a closely related species, R. ferrugineus, the red palm weevil (RPW), which is the biggest threat to palms in Asia and Europe. For both species, semiochemicals have been used for management. However, their control is far from complete. We generated an adult antennal transcriptome from APW and annotated chemosensory related gene families to obtain a better understanding of these species' olfaction mechanism. We identified unigenes encoding 37 odorant-binding proteins (OBPs), ten chemosensory proteins (CSPs), four sensory neuron membrane proteins (SNMPs), seven gustatory receptors (GRs), 63 odorant receptors (ORs), and 28 ionotropic receptors (IRs). Noticeably, we find out the R. ferrugineus pheromone-binding protein and pheromone receptor orthologs from R. palmarum. Candidate genes identified and annotated in this study allow us to compare these palm weevils' chemosensory gene sets. Most importantly, this study provides the foundation for functional studies that could materialize as novel pest management strategies.


Assuntos
Arecaceae/parasitologia , Sequenciamento do Exoma/métodos , Genes de Insetos/genética , Estudos de Associação Genética/métodos , Proteínas de Insetos/genética , Proteínas de Insetos/isolamento & purificação , Olfato/genética , Gorgulhos/genética , Gorgulhos/fisiologia , Animais , Ásia , Europa (Continente) , América do Norte , Controle Biológico de Vetores/métodos
16.
PLoS Pathog ; 17(4): e1009552, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33901257

RESUMO

Host genetic variation plays an important role in the structure and function of heritable microbial communities. Recent studies have shown that insects use immune mechanisms to regulate heritable symbionts. Here we test the hypothesis that variation in symbiont density among hosts is linked to intraspecific differences in the immune response to harboring symbionts. We show that pea aphids (Acyrthosiphon pisum) harboring the bacterial endosymbiont Regiella insecticola (but not all other species of symbionts) downregulate expression of key immune genes. We then functionally link immune expression with symbiont density using RNAi. The pea aphid species complex is comprised of multiple reproductively-isolated host plant-adapted populations. These 'biotypes' have distinct patterns of symbiont infections: for example, aphids from the Trifolium biotype are strongly associated with Regiella. Using RNAseq, we compare patterns of gene expression in response to Regiella in aphid genotypes from multiple biotypes, and we show that Trifolium aphids experience no downregulation of immune gene expression while hosting Regiella and harbor symbionts at lower densities. Using F1 hybrids between two biotypes, we find that symbiont density and immune gene expression are both intermediate in hybrids. We propose that in this system, Regiella symbionts are suppressing aphid immune mechanisms to increase their density, but that some hosts have adapted to prevent immune suppression in order to control symbiont numbers. This work therefore suggests that antagonistic coevolution can play a role in host-microbe interactions even when symbionts are transmitted vertically and provide a clear benefit to their hosts. The specific immune mechanisms that we find are downregulated in the presence of Regiella have been previously shown to combat pathogens in aphids, and thus this work also highlights the immune system's complex dual role in interacting with both beneficial and harmful microbes.


Assuntos
Afídeos/microbiologia , Carga Bacteriana/genética , Enterobacteriaceae/imunologia , Imunidade Inata/genética , Simbiose , Animais , Afídeos/classificação , Afídeos/genética , Afídeos/imunologia , Carga Bacteriana/fisiologia , Enterobacteriaceae/classificação , Enterobacteriaceae/citologia , Enterobacteriaceae/genética , Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Genes de Insetos/genética , Variação Genética/fisiologia , Interações entre Hospedeiro e Microrganismos/genética , Interações entre Hospedeiro e Microrganismos/imunologia , Especificidade da Espécie , Simbiose/genética , Simbiose/imunologia
17.
Zootaxa ; 4963(3): zootaxa.4963.3.4, 2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33903541

RESUMO

The subgenus Amblypteraca Mas-Peinado, Buckley, Ruiz García-París, 2018 of Pimelia Fabricius, 1775, is restricted to the southern Iberian Peninsula and western Maghreb (northern and western Morocco). The distribution of Amblypteraca throughout the African-European edges overlaps largely with the geographic range of the subgenus Amblyptera, which is sister to the clade grouping subgenera Amblypteraca and Ecphoroma Solier, 1836. Delimiting species boundaries in the speciose genus Pimelia is often challenging, and the taxonomic status of some groups within the aforementioned subgenera is still a matter of debate. Here, we aim to stabilize some of the available names in Amblypteraca, and to correct some previous misidentifications. For that purpose, we discuss the composition and taxonomic structure within Amblypteraca by (i) assessing the phylogenetic congruence between mitochondrial and nuclear markers, and (ii) examining external morphological traits in 568 Amblypteraca specimens under the light of the phylogenetic hypotheses proposed here. Based on our results, Amblypteraca consists of three species: P. rotundipennis Kraatz, 1865, P. fairmairii Kraatz, 1865 and P. chrysomeloides Pallas, 1781. Both molecular and morphological data revealed four lineages within P. chrysomeloides: P. chrysomeloides chrysomeloides, distributed on both sides of the Strait of Gibraltar; P. chrysomeloides fornicata Herbst, 1799 from Portugal (Troia region); P. chrysomeloides bathyglypta Antoine, 1949, restricted to a narrow strip between Larache and Arbaoua (northern atlantic Moroccan coast), and P. chrysomeloides subris Koch, 1941 from Kenitra-La Mamora forest (Morocco). We designate a neotype of Tenebrio chrysomeloides Pallas, 1781 and propose the synonymy of P. chrysomeloides (Pallas, 1781) = P. obesa Solier, 1836 syn. n. Pimelia tristis Haag-Rutenberg, 1875, previously misidentified and included in Amblypteraca, is now transferred back to Amblyptera. Further studies with ad hoc sampling designs and analytical tools would be in need to delimit the exact geographic ranges of these taxa, and to analyse the patterns of diversity within and among species and subspecies.


Assuntos
Besouros , Filogenia , Animais , Classificação , Besouros/anatomia & histologia , Besouros/classificação , Besouros/genética , Genes de Insetos/genética , Marrocos , Espanha , Especificidade da Espécie
18.
PLoS Pathog ; 17(3): e1009424, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33690727

RESUMO

Maintenance of a balance between the levels of viral replication and selective pressure from the immune systems of insect vectors is one of the prerequisites for efficient transmission of insect-borne propagative phytoviruses. The mechanism regulating the adaptation of RNA viruses to insect vectors by genomic variation remains unknown. Our previous study demonstrated an extension of the 3'-untranslated terminal region (UTR) of two genomic segments of rice stripe virus (RSV). In the present study, a reverse genetic system for RSV in human cells and an insect vector, the small brown planthopper Laodelphax striatellus, was used to demonstrate that the 3'-terminal extensions suppressed viral replication in vector insects by inhibiting promoter activity due to structural interference with the panhandle structure formed by viral 3'- and 5'-UTRs. The extension sequence in the viral RNA1 segment was targeted by an endogenous insect microRNA, miR-263a, which decreased the inhibitory effect of the extension sequence on viral promoter activity. Surprisingly, the expression of miR-263a was negatively regulated by RSV infection. This elaborate coordination between terminal variation of the viral genome and endogenous insect microRNAs controls RSV replication in planthopper, thus reflecting a distinct strategy of adaptation of phytoviruses to insect vectors.


Assuntos
Genes de Insetos/genética , Genes Virais/genética , Insetos Vetores/genética , Insetos Vetores/virologia , Tenuivirus/genética , Animais , Humanos , MicroRNAs/genética , Replicação Viral/genética
19.
J Insect Sci ; 21(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33620485

RESUMO

The lacewing Chrysoperla sinica (Tjeder) is a common natural enemy of many insect pests in China and is frequently employed for biological control programs. Adults make migratory flights after emergence, which reduces their effectiveness as biological control agents. Previously, we proved that 2-d-old unmated females exhibited significantly stronger flight ability than 3-d-old ones. Meanwhile, 3-d-old unmated adults flew significantly longer distances than mated ones. In this study, Illumina RNA sequencing was performed to characterize differentially expressed genes (DEGs) between virgin and mated adults of different ages in a single female strain of C. sinica. In total, 713,563,726 clean reads were obtained and de novo assembled into 109,165 unigenes with an average length of 847 bp (N50 of 1,754 bp), among which 4,382 (4.01%) unigenes matched known proteins. Based on these annotations, many putative transcripts were related to C. sinica's flight capacity and muscle structure, energy supply, growth, development, environmental adaptability, and metabolism of nutritional components and bioactive components. In addition, the differential expression of transcripts between different ages and mating status were analyzed, and DEGs participating in flight capacity and muscles were detected, including glutathione hydrolase, NAD-specific glutamate dehydrogenase, aminopeptidase, and acidic amino acid decarboxylase. The DEGs with functions associated with flight capacity and muscles exhibited higher transcript levels for younger (2 d--old) virgins. This comprehensive C. sinica transcriptomic data provide a foundation for a better understanding of the molecular mechanisms underlying the flight capacity to meet the physiological demands of flight muscles in C. sinica.


Assuntos
Voo Animal , Genes de Insetos/genética , Insetos/fisiologia , Transcriptoma/fisiologia , Animais , Insetos/genética
20.
Sci Rep ; 11(1): 4156, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33603202

RESUMO

The autonomy of segment-specific regulatory domains in the Bithorax complex is conferred by boundary elements and associated Polycomb response elements (PREs). The Fab-6 boundary is located at the junction of the iab-5 and iab-6 domains. Previous studies mapped it to a nuclease hypersensitive region 1 (HS1), while the iab-6 PRE was mapped to a second hypersensitive region HS2 nearly 3 kb away. To analyze the role of HS1 and HS2 in boundary we generated deletions of HS1 or HS1 + HS2 that have attP site for boundary replacement experiments. The 1389 bp HS1 deletion can be rescued by a 529 bp core Fab-6 sequence that includes two CTCF sites. However, Fab-6 HS1 cannot rescue the HS1 + HS2 deletion or substitute for another BX-C boundary - Fab-7. For this it must be combined with a PRE, either Fab-7 HS3, or Fab-6 HS2. These findings suggest that the boundary function of Fab-6 HS1 must be bolstered by a second element that has PRE activity.


Assuntos
Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Genes Homeobox/genética , Genes de Insetos/genética , Elementos de Resposta/genética , Animais , Deleção de Genes , Elementos Isolantes/genética , Proteínas do Grupo Polycomb/genética
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