Transcriptomic response of the insect vector, Peregrinus maidis, to Maize mosaic rhabdovirus and identification of conserved responses to propagative viruses in hopper vectors

Abstract Background Insect growth regulators (IGRs) can control insect vector populations by disrupting growth and development in juvenile stages of the vectors. We previously identified and described the curry tree (Murraya koenigii (L.) Spreng) phytochemical leaf extract composition (neplanocin A, 3-(1-naphthyl)-l-alanine, lumiflavine, terezine C, agelaspongin and murrayazolinol), which disrupted growth and development in Anopheles gambiae sensu stricto mosquito larvae by inducing morphogenetic abnormalities, reducing locomotion and delaying pupation in the mosquito. Here, we attempted to establish the transcriptional process in the larvae that underpins these phenotypes in the mosquito. Methods We first exposed third-fourth instar larvae of the mosquito to the leaf extract and consequently the inherent phytochemicals (and corresponding non-exposed controls) in two independent biological replicates. We collected the larvae for our experiments sampled 24 h before peak pupation, which was 7 and 18 days post-exposure for controls and exposed larvae, respectively. The differences in duration to peak pupation were due to extract-induced growth delay in the larvae. The two study groups (exposed vs control) were consequently not age-matched. We then sequentially (i) isolated RNA (whole larvae) from each replicate treatment, (ii) sequenced the RNA on Illumina HiSeq platform, (iii) performed differential bioinformatics analyses between libraries (exposed vs control) and (iv) independently validated the transcriptome expression profiles through RT-qPCR. Results Our analyses revealed significant induction of transcripts predominantly associated with hard cuticular proteins, juvenile hormone esterases, immunity and detoxification in the larvae samples exposed to the extract relative to the non-exposed control samples. Our analysis also revealed alteration of pathways functionally associated with putrescine metabolism and structural constituents of the cuticle in the extract-exposed larvae relative to the non-exposed control, putatively linked to the exoskeleton and immune response in the larvae. The extract-exposed larvae also appeared to have suppressed pathways functionally associated with molting, cell division and growth in the larvae. However, given the age mismatch between the extract-exposed and non-exposed larvae, we can attribute the modulation of innate immune, detoxification, cuticular and associated transcripts and pathways we observed to effects of age differences among the larvae samples (exposed vs control) and to exposures of the larvae to the extract. Conclusions The exposure treatment appears to disrupt cuticular development, immune response and oxidative stress pathways in Anopheles gambiae s.s larvae. These pathways can potentially be targeted in development of more efficacious curry tree phytochemical-based IGRs against An. gambiae s.s mosquito larvae.

Download Full-text

Interactions Between Maize Mosaic and Maize Stripe Viruses in Their Insect Vector,Peregrinus maidis,and in Maize

Phytopathology ◽

10.1094/phyto-77-1051 ◽

1987 ◽

Vol 77 (6) ◽

pp. 1051 ◽

Cited By ~ 19

Author(s):

E. D. Ammar

Keyword(s):

Insect Vector ◽

Peregrinus Maidis

Download Full-text

The Phlebotomus papatasi transcriptomic response to trypanosomatid-contaminated blood is robust but non-specific

10.1101/867382 ◽

2019 ◽

Author(s):

Megan A. Sloan ◽

Jovana Sadlova ◽

Tereza Lestinova ◽

Mandy J. Sanders ◽

James A. Cotton ◽

...

Keyword(s):

Blood Meal ◽

Leishmania Donovani ◽

Leishmania Major ◽

Blood Feeding ◽

Sand Fly ◽

Insect Vector ◽

Sand Flies ◽

Phlebotomus Papatasi ◽

Transcriptomic Response ◽

Gene Expression Response

AbstractLeishmaniasis, caused by parasites of the genus Leishmania, is a disease that effects up to 8 million people worldwide. Parasites are transmitted to human and animal hosts through the bite of an infected sand fly. Novel strategies for disease control, require a better understanding of the key step for transmission namely, the establishment of infection inside the fly. In this work we wanted to identify fly transcriptomic signatures associated with infection success or failure. We used next generation sequencing to describe the transcriptome of the sand fly Phlebotomus papatasi when fed with blood alone or with blood containing one of three trypanosomatids: Leishmania major, Leishmania donovani and Herpetomonas muscarum: a parasite not transmitted to humans. Of these, only L. major was able to successfully establish an infection in P. papatasi. However, the transcriptional signatures observed were not specific to success or failure of infection but a generalised response to the blood meal. This implies that sand flies perceive Leishmania as just a feature of their microbiome landscape and that any strategy to tackle transmission should focus on the response towards the blood meal rather than parasite establishment.Authors summaryLeishmania are parasites that cause leishmaniasis, a group of serious diseases that affect millions of people, mainly across the subtropics and tropics. They are transmitted to humans by phlebotomine sand flies. However, despite establishment in the insect’s midgut being key to transmission, early infection events inside the insect are still unclear. Here, we study the gene expression response of the insect vector to a Leishmania parasite that is able to establish infection (L. major) one that is unable to do so (L. donovani) as well as one that is not a natural parasite of sand flies (Herpetomonas muscarum). We found that responses following any of the infected blood meals was very similar to uninfected blood meal. However, changes post-blood meal from day 1 to day 9 were dramatic. As a blood feeding insect can accumulate three times its weight in one blood meal, this seems to be the most important physiological change rather than the presence of the parasite. The latter might be just one in a number of microbes the insect encounters. This result will generate new thinking around the concept of stopping transmission by controlling the parasite inside the insect.

Download Full-text

A scanning electron microscopic study of the eggs of Culicoides variipennis (Diptera: Ceratopogonidae)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128705 ◽

1987 ◽

Vol 45 ◽

pp. 884-885 ◽

Cited By ~ 1

Author(s):

R. A. Nunamaker ◽

C. E. Nunamaker ◽

B. C. Wick

Keyword(s):

Distinct Species ◽

Hemorrhagic Disease ◽

Insect Vector ◽

Electron Microscopic ◽

Important Species ◽

Scanning Electron Microscopic Study ◽

Laboratory Colony ◽

Culicoides Variipennis ◽

Morphological Differences ◽

Scanning Electron

Culicoides variipennis (Coquillett) is probably the most economically important species of biting midge in the U.S. due to its involvement in the transmission of bluetongue (BT) disease of sheep, cattle and ruminant wildlife, and epizootic hemorrhagic disease (EHD) of deer. Proposals have been made to recognize the eastern and western populations of this insect vector as distinct species. Others recommend use of the term “variipennis complex” until such time that the necessary biosystematic studies have been made to determine the genetic nature and/or minute morphological differences within the population structure over the entire geographic range of the species. Increasingly, students of ootaxonomy are relying on scanning electron microscopy (SEM) to assess chorionic features. This study was undertaken to provide comparative chorionic data for the C. variipennis complex.Culicoides variipennis eggs were collected from a laboratory colony maintained in Laramie, Wyoming.

Download Full-text

Scent Sensors Are New Target for Repellents To Curb Insect Vector-Borne Diseases

Microbe Magazine ◽

10.1128/microbe.4.312.1 ◽

2009 ◽

Vol 4 (7) ◽

pp. 312-312

Keyword(s):

Insect Vector ◽

Vector Borne Diseases ◽

Vector Borne

Download Full-text

Metabolic reprogramming during the Trypanosoma brucei life cycle

F1000Research ◽

10.12688/f1000research.10342.2 ◽

2017 ◽

Vol 6 ◽

pp. 683 ◽

Cited By ~ 31

Author(s):

Terry K. Smith ◽

Frédéric Bringaud ◽

Derek P. Nolan ◽

Luisa M. Figueiredo

Keyword(s):

Life Cycle ◽

Trypanosoma Brucei ◽

Model Organism ◽

Protozoan Parasite ◽

Tsetse Fly ◽

Metabolic Reprogramming ◽

Mammalian Host ◽

Insect Vector ◽

Environmental Signals ◽

Cellular Metabolic Activity

Cellular metabolic activity is a highly complex, dynamic, regulated process that is influenced by numerous factors, including extracellular environmental signals, nutrient availability and the physiological and developmental status of the cell. The causative agent of sleeping sickness, Trypanosoma brucei, is an exclusively extracellular protozoan parasite that encounters very different extracellular environments during its life cycle within the mammalian host and tsetse fly insect vector. In order to meet these challenges, there are significant alterations in the major energetic and metabolic pathways of these highly adaptable parasites. This review highlights some of these metabolic changes in this early divergent eukaryotic model organism.

Download Full-text

Charged Residues Flanking the Transmembrane Domain of Two Related Toxin–Antitoxin System Toxins Affect Host Response

Toxins ◽

10.3390/toxins13050329 ◽

2021 ◽

Vol 13 (5) ◽

pp. 329

Author(s):

Andrew Holmes ◽

Jessie Sadlon ◽

Keith Weaver

Keyword(s):

Amino Acid ◽

Enterococcus Faecalis ◽

Host Response ◽

Cytoplasmic Membrane ◽

Transmembrane Domain ◽

The Other ◽

Type I ◽

Transcriptomic Response ◽

Specific Amino Acid ◽

Transporter Protein

A majority of toxins produced by type I toxin–antitoxin (TA-1) systems are small membrane-localized proteins that were initially proposed to kill cells by forming non-specific pores in the cytoplasmic membrane. The examination of the effects of numerous TA-1 systems indicates that this is not the mechanism of action of many of these proteins. Enterococcus faecalis produces two toxins of the Fst/Ldr family, one encoded on pheromone-responsive conjugative plasmids (FstpAD1) and the other on the chromosome, FstEF0409. Previous results demonstrated that overexpression of the toxins produced a differential transcriptomic response in E. faecalis cells. In this report, we identify the specific amino acid differences between the two toxins responsible for the differential response of a gene highly induced by FstpAD1 but not FstEF0409. In addition, we demonstrate that a transporter protein that is genetically linked to the chromosomal version of the TA-1 system functions to limit the toxicity of the protein.

Download Full-text

Sequential production of gametes during meiosis in trypanosomes

Communications Biology ◽

10.1038/s42003-021-02058-5 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Lori Peacock ◽

Chris Kay ◽

Chloe Farren ◽

Mick Bailey ◽

Mark Carrington ◽

...

Keyword(s):

Salivary Glands ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Cell Types ◽

Tsetse Fly ◽

Binucleate Cell ◽

Insect Vector ◽

Content Ratio ◽

Different Cell Types ◽

Meiosis I

AbstractMeiosis is a core feature of eukaryotes that occurs in all major groups, including the early diverging excavates. In this group, meiosis and production of haploid gametes have been described in the pathogenic protist, Trypanosoma brucei, and mating occurs in the salivary glands of the insect vector, the tsetse fly. Here, we searched for intermediate meiotic stages among trypanosomes from tsetse salivary glands. Many different cell types were recovered, including trypanosomes in Meiosis I and gametes. Significantly, we found trypanosomes containing three nuclei with a 1:2:1 ratio of DNA contents. Some of these cells were undergoing cytokinesis, yielding a mononucleate gamete and a binucleate cell with a nuclear DNA content ratio of 1:2. This cell subsequently produced three more gametes in two further rounds of division. Expression of the cell fusion protein HAP2 (GCS1) was not confined to gametes, but also extended to meiotic intermediates. We propose a model whereby the two nuclei resulting from Meiosis I undergo asynchronous Meiosis II divisions with sequential production of haploid gametes.

Download Full-text

Environmental Conditions Modulate the Transcriptomic Response of Both Caulobacter crescentus Morphotypes to Cu Stress

Microorganisms ◽

10.3390/microorganisms9061116 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1116

Author(s):

Laurens Maertens ◽

Pauline Cherry ◽

Françoise Tilquin ◽

Rob Van Houdt ◽

Jean-Yves Matroule

Keyword(s):

Oxidative Stress ◽

Stress Response ◽

Stress Responses ◽

Caulobacter Crescentus ◽

Oxidative Stress Response ◽

Transport Systems ◽

Transcriptomic Response ◽

Swarmer Cell ◽

Cu Stress ◽

Cellular Environment

Bacteria encounter elevated copper (Cu) concentrations in multiple environments, varying from mining wastes to antimicrobial applications of copper. As the role of the environment in the bacterial response to Cu ion exposure remains elusive, we used a tagRNA-seq approach to elucidate the disparate responses of two morphotypes of Caulobacter crescentus NA1000 to moderate Cu stress in a complex rich (PYE) medium and a defined poor (M2G) medium. The transcriptome was more responsive in M2G, where we observed an extensive oxidative stress response and reconfiguration of the proteome, as well as the induction of metal resistance clusters. In PYE, little evidence was found for an oxidative stress response, but several transport systems were differentially expressed, and an increased need for histidine was apparent. These results show that the Cu stress response is strongly dependent on the cellular environment. In addition, induction of the extracytoplasmic function sigma factor SigF and its regulon was shared by the Cu stress responses in both media, and its central role was confirmed by the phenotypic screening of a sigF::Tn5 mutant. In both media, stalked cells were more responsive to Cu stress than swarmer cells, and a stronger basal expression of several cell protection systems was noted, indicating that the swarmer cell is inherently more Cu resistant. Our approach also allowed for detecting several new transcription start sites, putatively indicating small regulatory RNAs, and additional levels of Cu-responsive regulation.

Download Full-text