Wolbachia cifB induces cytoplasmic incompatibility in the malaria mosquito vector

AbstractWolbachia, a maternally inherited intracellular bacterial species, can manipulate host insect reproduction by cytoplasmic incompatibility (CI), which results in embryo lethality in crosses between infected males and uninfected females. CI is encoded by two prophage genes, cifA and cifB. Wolbachia, coupled with the sterile insect technique, has been used in field trials to control populations of the dengue vector Aedes albopictus, but CI-inducing strains are not known to infect the malaria vector Anopheles gambiae. Here we show that cifA and cifB can induce conditional sterility in the malaria vector An. gambiae. We used transgenic expression of these Wolbachia-derived genes in the An. gambiae germline to show that cifB is sufficient to cause embryonic lethality and that cifB-induced sterility is rescued by cifA expression in females. When we co-expressed cifA and cifB in male mosquitoes, the CI phenotype was attenuated. In female mosquitoes, cifB impaired fertility, which was overcome by co-expression of cifA. Our findings pave the way towards using CI to control malaria mosquito vectors.

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STUDI BIONOMIK VEKTOR MALARIA DI KECAMATAN KALIBAWANG, KULONPROGO

Jurnal Rekayasa Lingkungan ◽

10.29122/jrl.v4i2.1859 ◽

2018 ◽

Vol 4 (2) ◽

Author(s):

Sardjito Eko Windarso dkk

Keyword(s):

Land Use ◽

Malaria Vector ◽

Rainy Season ◽

Dry Season ◽

Physical Factors ◽

Mosquito Vector ◽

Anopheles Species ◽

Commercial Farming ◽

Study Results ◽

Dry And Rainy Seasons

The increasing of malaria cases in recent years at Kecamatan Kalibawang has been suspected correspond with the conversion of farming land-use which initiated in 1993. Four years after the natural vegetation in this area were changed become cocoa and coffee commercial farming estates, the number of malaria cases in 1997 rose more than six times, and in 2000 it reached 6085. This study were aimed to observe whether there were any differences in density and diversity of Anopheles as malaria vector between the cocoa and mix farming during dry and rainy seasons. The results of the study are useful for considering the appropriate methods, times and places for mosquito vector controlling. The study activities comprised of collecting Anopheles as well as identifying the species to determine the density and diversity of the malaria vector. Both activities were held four weeks in dry season and four weeks in rainy season. The mea-surement of physical factors such as temperature, humidity and rainfall were also conducted to support the study results. Four dusuns which meet the criteria and had the highest malaria cases were selected as study location. Descriptively, the results shows that the number of collected Anopheles in cocoa farming were higher compared with those in mix horticultural farming; and the number of Anopheles species identifi ed in cocoa farming were also more varied than those in the mix horticultural farming.Key words: bionomik vektor malaria, anopheles,

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Transgenic Expression of the Anti-parasitic Factor TEP1 in the Malaria Mosquito Anopheles gambiae

PLoS Pathogens ◽

10.1371/journal.ppat.1006113 ◽

2017 ◽

Vol 13 (1) ◽

pp. e1006113 ◽

Cited By ~ 24

Author(s):

Gloria Volohonsky ◽

Ann-Katrin Hopp ◽

Mélanie Saenger ◽

Julien Soichot ◽

Heidi Scholze ◽

...

Keyword(s):

Anopheles Gambiae ◽

Malaria Mosquito ◽

Transgenic Expression ◽

Mosquito Anopheles Gambiae

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One prophage WO gene rescues cytoplasmic incompatibility in Drosophila melanogaster

10.1101/300269 ◽

2018 ◽

Author(s):

J. Dylan Shropshire ◽

Jungmin On ◽

Emily M. Layton ◽

Helen Zhou ◽

Seth R. Bordenstein

Keyword(s):

Drosophila Melanogaster ◽

Vector Control ◽

Genetic Basis ◽

Cytoplasmic Incompatibility ◽

Embryo Rescue ◽

Field Trials ◽

Current Control ◽

Drive System ◽

World Health ◽

Fitness Advantage

AbstractWolbachia are maternally-inherited, intracellular bacteria at the forefront of vector control efforts to curb arbovirus transmission. In international field trials, the cytoplasmic incompatibility (CI) drive system of wMel Wolbachia is deployed to replace target vector populations, whereby a Wolbachia– induced modification of the sperm genome kills embryos. However, Wolbachia in the embryo rescue the sperm genome impairment, and therefore CI results in a strong fitness advantage for infected females that transmit the bacteria to offspring. The two genes responsible for the wMel-induced sperm modification of CI, cifA and cifB, were recently identified in the eukaryotic association module of prophage WO, but the genetic basis of rescue is unresolved. Here we use transgenic and cytological approaches to demonstrate that cifA independently rescues CI and nullifies embryonic death caused by wMel Wolbachia in Drosophila melanogaster. Discovery of cifA as the rescue gene and previously one of two CI induction genes establishes a new ‘Two-by-One’ model that underpins the genetic basis of CI. Results highlight the central role of prophage WO in shaping Wolbachia phenotypes that are significant to arthropod evolution and vector control.Significance StatementThe World Health Organization recommended pilot deployment of Wolbachia-infected mosquitoes to curb viral transmission to humans. Releases of mosquitoes are underway worldwide because Wolbachia can block replication of these pathogenic viruses and deterministically spread by a drive system termed cytoplasmic incompatibility (CI). Despite extensive research, the underlying genetic basis of CI remains only half-solved. We recently reported that two prophage WO genes recapitulate the modification component of CI in a released strain for vector control. Here we show that one of these genes underpins rescue of CI. Together, our results reveal the complete genetic basis of this selfish trait and pave the way for future studies exploring WO prophage genes as adjuncts or alternatives to current control efforts.

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Wild chive oil is an extremely effective larvicide against malaria mosquito vector Anopheles stephensi

Asian Pacific Journal of Tropical Medicine ◽

10.4103/1995-7645.257117 ◽

2019 ◽

Vol 12 (4) ◽

pp. 170 ◽

Cited By ~ 2

Author(s):

Moussa Soleimani-Ahmadi ◽

Alireza Sanei-Dehkordi ◽

YaserSalim Abadi ◽

Azim Paksa

Keyword(s):

Anopheles Stephensi ◽

Mosquito Vector ◽

Malaria Mosquito

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Some methodological issues in the development of public health recommendations from field trials of new malaria vector control interventions

Malaria Journal ◽

10.1186/1475-2875-11-s1-p134 ◽

2012 ◽

Vol 11 (S1) ◽

Author(s):

Jo Lines

Keyword(s):

Public Health ◽

Vector Control ◽

Malaria Vector ◽

Field Trials ◽

Malaria Vector Control ◽

Methodological Issues

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Effect of phyto-synthesized silver nanoparticles on developmental stages of malaria vector, Anopheles stephensi and dengue vector, Aedes aegypti

Egyptian Journal of Basic and Applied Sciences ◽

10.1016/j.ejbas.2017.04.005 ◽

2017 ◽

Vol 4 (3) ◽

pp. 212-218 ◽

Cited By ~ 8

Author(s):

Madanagopal Nalini ◽

Mahalingam Lena ◽

Palanisamy Sumathi ◽

Chandran Sundaravadivelan

Keyword(s):

Silver Nanoparticles ◽

Aedes Aegypti ◽

Malaria Vector ◽

Anopheles Stephensi ◽

Developmental Stages ◽

Dengue Vector

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Transgenic Testing Does Not Support a Role for Additional Candidate Genes in Wolbachia Male Killing or Cytoplasmic Incompatibility

mSystems ◽

10.1128/msystems.00658-19 ◽

2020 ◽

Vol 5 (1) ◽

Author(s):

Jessamyn I. Perlmutter ◽

Jane E. Meyers ◽

Seth R. Bordenstein

Keyword(s):

Drosophila Melanogaster ◽

Copy Number ◽

Cytoplasmic Incompatibility ◽

Functional Study ◽

Content Type ◽

Transgenic Expression ◽

Additional Gene ◽

Reproductive Parasitism ◽

Transcript Length ◽

Male Killing

ABSTRACT Endosymbiotic bacteria in the genus Wolbachia remarkably infect nearly half of all arthropod species. They spread in part because of manipulations of host sexual reproduction that enhance the maternal transmission of the bacteria, including male killing (death of infected males) and unidirectional cytoplasmic incompatibility (CI; death of offspring from infected fathers and uninfected mothers). Recent discoveries identified several genes in prophage WO of Wolbachia (wmk, cifA, and cifB) that fully or partially recapitulate male killing or CI when transgenically expressed in Drosophila melanogaster. However, it is not yet fully resolved if other gene candidates contribute to these phenotypes. Here, we transgenically tested 10 additional gene candidates for their involvement in male killing and/or CI. The results show that despite sequence and protein architecture similarities or comparative associations with reproductive parasitism, transgenic expression of the candidates does not recapitulate male killing or CI. Sequence analysis across Wmk and its closest relatives reveals amino acids that may be important to its function. In addition, evidence is presented to propose new hypotheses regarding the relationship between wmk transcript length and its ability to kill a given host, as well as copy number of wmk homologs within a bacterial strain, which may be predictive of host resistance. Together, these analyses continue to build the evidence for identification of wmk, cifA, and cifB as the major genes that have thus far been shown to cause reproductive parasitism in Wolbachia, and the transgenic resources provide a basis for further functional study of phage WO genes. IMPORTANCE Wolbachia are widespread bacterial endosymbionts that manipulate the reproduction of diverse arthropods to spread through a population and can substantially shape host evolution. Recently, reports identified three prophage WO genes (wmk, cifA, and cifB) that transgenically recapitulate many aspects of reproductive manipulation in Drosophila melanogaster. Here, we transgenically tested 10 additional gene candidates for CI and/or male killing in flies. The results yield no evidence for the involvement of these gene candidates in reproductive parasitism, bolstering the evidence for identification of the cif and wmk genes as the major factors involved in their phenotypes. In addition, evidence supports new hypotheses for prediction of male-killing phenotypes or lack thereof based on wmk transcript length and copy number. These experiments inform efforts to understand the full basis of reproductive parasitism for basic and applied purposes and lay the foundation for future work on the function of an interesting group of Wolbachia and phage WO genes.

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Evaluation of mosquito electrocuting traps as a safe alternative to the human landing catch for measuring human exposure to malaria vectors in Burkina Faso

Malaria Journal ◽

10.1186/s12936-019-3030-5 ◽

2019 ◽

Vol 18 (1) ◽

Cited By ~ 1

Author(s):

Antoine Sanou ◽

W. Moussa Guelbéogo ◽

Luca Nelli ◽

K. Hyacinth Toé ◽

Soumanaba Zongo ◽

...

Keyword(s):

Species Composition ◽

Burkina Faso ◽

Malaria Vector ◽

Human Exposure ◽

Infected Mosquito ◽

Malaria Vectors ◽

Human Landing Catch ◽

Mosquito Vector ◽

Human Landing ◽

Biting Behaviour

Abstract Background Measuring human exposure to mosquito bites is a crucial component of vector-borne disease surveillance. For malaria vectors, the human landing catch (HLC) remains the gold standard for direct estimation of exposure. This method, however, is controversial since participants risk exposure to potentially infected mosquito bites. Recently an exposure-free mosquito electrocuting trap (MET) was developed to provide a safer alternative to the HLC. Early prototypes of the MET performed well in Tanzania but have yet to be tested in West Africa, where malaria vector species composition, ecology and behaviour are different. The performance of the MET relative to HLC for characterizing mosquito vector population dynamics and biting behaviour in Burkina Faso was evaluated. Methods A longitudinal study was initiated within 12 villages in Burkina Faso in October 2016. Host-seeking mosquitoes were sampled monthly using HLC and MET collections over 14 months. Collections were made at 4 households on each night, with METs deployed inside and outside at 2 houses, and HLC inside and outside at another two. Malaria vector abundance, species composition, sporozoite rate and location of biting (indoor versus outdoor) were recorded. Results In total, 41,800 mosquitoes were collected over 324 sampling nights, with the major malaria vector being Anopheles gambiae sensu lato (s.l.) complex. Overall the MET caught fewer An. gambiae s.l. than the HLC (mean predicted number of 0.78 versus 1.82 indoors, and 1.05 versus 2.04 outdoors). However, MET collections gave a consistent representation of seasonal dynamics in vector populations, species composition, biting behaviour (location and time) and malaria infection rates relative to HLC. As the relative performance of the MET was somewhat higher in outdoor versus indoor settings, this trapping method slightly underestimated the proportion of bites preventable by LLINs compared to the HLC (MET = 82.08%; HLC = 87.19%). Conclusions The MET collected proportionately fewer mosquitoes than the HLC. However, estimates of An. gambiae s.l. density in METs were highly correlated with HLC. Thus, although less sensitive, the MET is a safer alternative than the HLC. Its use is recommended particularly for sampling vectors in outdoor environments where it is most sensitive.

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Effect of dengue mosquito control insecticide thermal fogging on non-target insects

International Journal of Tropical Insect Science ◽

10.1017/s1742758416000254 ◽

2016 ◽

Vol 37 (01) ◽

pp. 11-18 ◽

Cited By ~ 4

Author(s):

K.G. Thilanka N. Abeyasuriya ◽

N.W. Nalaka P. Nugapola ◽

M. Devika B. Perera ◽

W.A. Inoka P. Karunaratne ◽

S.H.P. Parakrama Karunaratne

Keyword(s):

Mosquito Control ◽

Recovery Period ◽

Mosquito Vector ◽

Dengue Vector ◽

Insect Order ◽

Severe Effect ◽

Control Programmes ◽

Control Adult ◽

Positive Controls ◽

Dengue Vector Control

AbstractDengue vector control programmes are mainly focused on insecticide fogging/space spraying to control adultAedesmosquito vector populations. Due to the diurnal habit of the vectors, spraying is routinely conducted during the day when many other insect species are also active. This study reports the simultaneous effect of fogging on non-target insects by direct counting of knockdown in the insect population. Eight fogging treatments were conducted in two sites in Kurunegala District of Sri Lanka. Pesguard insecticide was sprayed in each treatment for 8 minutes according to the standard methodology and the ‘knockdown insects’ were collected on randomly spread polyethythene sheets (10 m2). A total of 3884 insects (24.3 insects per treatment per m2) belonging to 12 orders were collected and 12.44% of them recovered during a 24-hr recovery period. Diptera was the most affected insect order (36%) followed by Collembola (30%) and Thysanoptera (17%). Out of the 31 mosquitoes (<1%) collected, only two (<0.1%) belonged to the genusAedes. Body length of 93% of the affected insects ranged from 0.35 mm to 1.8 mm. Positive controls using the WHO standard cage bioassays with the mosquitoAe. albopictus(n = 417) and the stingless beeTrigona iridipennis(n = 122) showed 100% initial knockdown, and 83.5% mosquito and 93.5% bee mortalities after the recovery period. The study shows that insecticide fogging does have a severe effect on non-target insects such as pollinators; therefore, fogging operations should be done in a controlled manner and indiscriminate fogging should be avoided.

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