scholarly journals Extensive Genetic Differentiation between Homomorphic Sex Chromosomes in the Mosquito Vector, Aedes aegypti

2017 ◽  
Vol 9 (9) ◽  
pp. 2322-2335 ◽  
Author(s):  
Albin Fontaine ◽  
Igor Filipović ◽  
Thanyalak Fansiri ◽  
Ary A. Hoffmann ◽  
Changde Cheng ◽  
...  
2016 ◽  
Author(s):  
Albin Fontaine ◽  
Igor Filipović ◽  
Thanyalak Fansiri ◽  
Ary A. Hoffmann ◽  
Changde Cheng ◽  
...  

AbstractMechanisms and evolutionary dynamics of sex-determination systems are of particular interest in insect vectors of human pathogens like mosquitoes because novel control strategies aim to convert pathogen-transmitting females into non-biting males, or rely on accurate sexing for the release of sterile males. In Aedes aegypti, the main vector of dengue and Zika viruses, sex determination is governed by a dominant male-determining locus, previously thought to reside within a small, non-recombining, sex-determining region (SDR) of an otherwise homomorphic sex chromosome. Here, we provide evidence that sex chromosomes in Ae. aegypti are genetically differentiated between males and females over a region much larger than the SDR. Our linkage mapping intercrosses failed to detect recombination between X and Y chromosomes over a 123-Mbp region (40% of their physical length) containing the SDR. This region of reduced male recombination overlapped with a smaller 63-Mbp region (20% of the physical length of the sex chromosomes) displaying high male-female genetic differentiation in unrelated wild population from Brazil and Australia and in a reference laboratory strain originating from Africa. In addition, the sex-differentiated genomic region was associated with a significant excess of male-to-female heterozygosity and contained a small cluster of loci consistent with Y-specific null alleles. We demonstrate that genetic differentiation between sex chromosomes is sufficient to assign individuals to their correct sex with high accuracy. We also show how data on allele frequency differences between sexes can be used to estimate linkage disequilibrium between loci and the sex-determining locus. Our discovery of large-scale genetic differentiation between sex chromosomes in Ae. aegypti lays a new foundation for mapping and population genomic studies, as well as for mosquito control strategies targeting the sex-determination pathway.


2020 ◽  
Vol 10 (1) ◽  
pp. 67-77
Author(s):  
Amos Watentena ◽  
Ikem Chris Okoye ◽  
Ikechukwu Eugene Onah ◽  
Onwude Cosmas Ogbonnaya ◽  
Emmanuel Ogudu

Mosquitoes of Aedes species are vectors of several arboviral diseases which continue to be a major public health problem in Nigeria. This study among other things, morphologically identified Aedes mosquitoes collected from Nsukka LGA and used an allele specific PCR amplification for discrimination of dengue vectors. Larval sampling, BG-sentinel traps and modified human landing catches were used for mosquito sampling in two selected autonomous communities of Nsukka LGA (Nsukka and Obimo). A total of 124 Aedes mosquitoes consisting of five (5) different species were collected from April to June, 2019 in a cross-sectional study that covered 126 households, under 76 distinct geographical coordinates. Larvae was mainly collected from plastic containers 73% (n=224), metallic containers 14% (n=43), earthen pots 9% (n=29) and used car tyres 3% (n=9), reared to adult stage 69.35% (n=86), and all mosquitoes were identified using standard morphological keys. Five (5) Aedes mosquito species were captured; Aedes aegypti 83(66.94%), Aedes albopictus 33(26.61%), Aedes simpsoni (4.48%), Aedes luteocephalus (≤1%) and Aedes vittatus (≤1%). Nsukka autonomous community had higher species diversity than Obimo. Allele specific amplification confirmed dengue vectors, Aedes aegypti and Aedes albopictus species on a 2% agarose gel. Since the most recent re-emergence of arboviral diseases is closely associated with Aedes species, findings of this study, therefore, give further evidence about the presence of potential arboviral vectors in Nigeria and describe the role of a simple PCR in discriminating some. Further entomological studies should integrate PCR assays in mosquito vector surveillance.


2021 ◽  
Vol 16 (2) ◽  
pp. 1934578X2199019 ◽  
Author(s):  
Iris Stappen ◽  
Juergen Wanner ◽  
Nurhayat Tabanca ◽  
Ulrich R. Bernier ◽  
Paul E. Kendra

Blue tansy essential oil (BTEO) ( Tanacetum annuum L.) was analyzed by GC-MS and GC-FID using two different capillary column stationary phases. Sabinene (14.0%), camphor (13.6%), myrcene (8.0%), β-pinene (7.7%), and chamazulene (6.9%) were the main components using an SE52 column (non-polar). On a polar CW20M phase column, sabinene (15.1%), camphor (14.4%), α-phellandrene (7.9%), β-pinene (7.7%), and myrcene (6.9%) were the most abundant compounds. To assess the oil for potential applications in integrated pest management strategies, behavioral bioassays were conducted to test for repellency against yellow fever mosquito Aedes aegypti, and for attractant activity for Mediterranean fruit fly Ceratitis capitata. Results showed that BTEO was not effective in repelling Ae. aegypti (minimum effective dosage [MED]: 0.625 ± 0.109 mg/cm2 compared with the standard insect repellent DEET (N,N-diethyl-3-methylbenzamide). In assays with male C. capitata, BTEO displayed mild attraction compared with two positive controls (essential oils from tea tree Melaleuca alternifolia and African ginger bush Tetradenia riparia). Additional studies are needed to identify the specific attractant chemicals in BTEO and to determine if they confer a synergistic effect when combined with other known attractants for C. capitata. To the best of our knowledge, this study represents the first investigation of BTEO for repellency against the mosquito vector Ae. aegypti and for attractancy to C. capitata, a major agricultural pest worldwide.


2012 ◽  
Vol 6 (11) ◽  
pp. e1892 ◽  
Author(s):  
Andrew F. van den Hurk ◽  
Sonja Hall-Mendelin ◽  
Alyssa T. Pyke ◽  
Francesca D. Frentiu ◽  
Kate McElroy ◽  
...  

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 177 ◽  
Author(s):  
Tereza Magalhaes ◽  
Alexis Robison ◽  
Michael Young ◽  
William Black ◽  
Brian Foy ◽  
...  

In urban settings, chikungunya, Zika, and dengue viruses are transmitted by Aedes aegypti mosquitoes. Since these viruses co-circulate in several regions, coinfection in humans and vectors may occur, and human coinfections have been frequently reported. Yet, little is known about the molecular aspects of virus interactions within hosts and how they contribute to arbovirus transmission dynamics. We have previously shown that Aedes aegypti exposed to chikungunya and Zika viruses in the same blood meal can become coinfected and transmit both viruses simultaneously. However, mosquitoes may also become coinfected by multiple, sequential feeds on single infected hosts. Therefore, we tested whether sequential infection with chikungunya and Zika viruses impacts mosquito vector competence. We exposed Ae. aegypti mosquitoes first to one virus and 7 days later to the other virus and compared infection, dissemination, and transmission rates between sequentially and single infected groups. We found that coinfection rates were high after sequential exposure and that mosquitoes were able to co-transmit both viruses. Surprisingly, chikungunya virus coinfection enhanced Zika virus transmission 7 days after the second blood meal. Our data demonstrate heterologous arbovirus synergism within mosquitoes, by unknown mechanisms, leading to enhancement of transmission under certain conditions.


2018 ◽  
Vol 4 (2) ◽  
pp. 83-90
Author(s):  
Ign Joko Suyono ◽  
Aditya K. Karim

Dengue is the most important emerging tropical viral disease of humans in the world today. Aedes aegypti is a major mosquito vector responsible for transmitting many viral diseases and this mosquito that spreads major health problems like dengue fever. The resistance of Ae. aegypti to insecticides is already widespread and represents a serious problem for programmes aimed at the control and prevention of dengue in tropical countries. The search for compounds extracted from medicinal plant preparations as alternatives insecticide for mosquito control is in immediate need. Alternative approach for control Ae. aegypti dan virus dengue using the medicinal plant will be discussed in this paper.Key words: Medicinal plant, Aedes aegypti, dengue fever, dengue haemorragi fever, dengue shock syndrome


2021 ◽  
Vol 12 ◽  
Author(s):  
Thiago H. J. F. Leite ◽  
Álvaro G. A. Ferreira ◽  
Jean-Luc Imler ◽  
João T. Marques

Aedes aegypti mosquitoes are vectors for arboviruses of medical importance such as dengue (DENV) and Zika (ZIKV) viruses. Different innate immune pathways contribute to the control of arboviruses in the mosquito vector including RNA interference, Toll and Jak-STAT pathways. However, the role of cellular responses mediated by circulating macrophage-like cells known as hemocytes remains unclear. Here we show that hemocytes are recruited to the midgut of Ae. aegypti mosquitoes in response to DENV or ZIKV. Blockade of the phagocytic function of hemocytes using latex beads induced increased accumulation of hemocytes in the midgut and a reduction in virus infection levels in this organ. In contrast, inhibition of phagocytosis by hemocytes led to increased systemic dissemination and replication of DENV and ZIKV. Hence, our work reveals a dual role for hemocytes in Ae. aegypti mosquitoes, whereby phagocytosis is not required to control viral infection in the midgut but is essential to restrict systemic dissemination. Further understanding of the mechanism behind this duality could help the design of vector-based strategies to prevent transmission of arboviruses.


2014 ◽  
Vol 3 (1) ◽  
pp. 31
Author(s):  
Rahmawati Ekaputri ◽  
Sudarsono Sudarsono ◽  
Budi Mulyaningsih

<p>Background: <em>Vinca rosea</em> is known contain alkaloids, it was usually used to treat various diseases. Alkaloids from Vinca leaves are also already known have larvicidal activity. Based on this toxicological activity, the fruit of <em>Vinca rosea</em> was selected to investigation its larvicidal activity against the 3<sup>rd</sup> instar larvae of the mosquito vector of dengue haemorrhagic fever (DHF) <em>Aedes aegypti.</em>  Five concentrations of Vinca fruit extract were tested against the 3<sup>rd</sup> instar Aedes aegypti larvae. The different larval mortality percentages were recorded after 24 hours. Lethal concentration (LC<sub>50</sub> anf LC<sub>90</sub>) of Vinca fruit extract were calculated using Probit analysis. Phytochemical compounds  of ethanolic extract also investigated using Thin layer Chromatography (TLC). LC<sub>50</sub> and LC<sub>90</sub> values of fruit extract were 2.987 mg/ml and 32.861 mg/ml. Alkaloids were detected in extract.</p>


2019 ◽  
Vol 57 (3) ◽  
pp. 830-836
Author(s):  
Aryana Zardkoohi ◽  
David Castañeda ◽  
Juan C Lol ◽  
Carmen Castillo ◽  
Francisco Lopez ◽  
...  

Abstract Aedes aegypti (Linnaeus, 1762) is considered the most important mosquito vector species for several arboviruses (e.g., dengue, chikungunya, Zika) in Costa Rica. The primary strategy for the control and prevention of Aedes-borne diseases relies on insecticide-based vector control. However, the emergence of insecticide resistance in the mosquito populations presents a significant threat to these prevention actions. The characterization of the mechanisms driving the insecticide resistance in Ae. aegypti is vital for decision making in vector control programs. Therefore, we analyzed the voltage-gated sodium channel (VGSC) gene for the presence of the V1016I and F1534C kdr mutations in Ae. aegypti populations from Puntarenas and Limon provinces, Costa Rica. The CDC bottle bioassays showed that both Costa Rican Ae. aegypti populations were resistant to permethrin and deltamethrin. In the case of kdr genotyping, results revealed the co-occurrence of V1016I and F1534C mutations in permethrin and deltamethrin-resistant populations, as well as the fixation of the 1534C allele. A strong association between these mutations and permethrin and deltamethrin resistance was found in Puntarenas. Limon did not show this association; however, our results indicate that the Limon population analyzed is not under the same selective pressure as Puntarenas for the VGSC gene. Therefore, our findings make an urgent call to expand the knowledge about the insecticide resistance status and mechanisms in the Costa Rican populations of Ae. aegypti, which must be a priority to develop an effective resistance management plan.


Sign in / Sign up

Export Citation Format

Share Document