Review articleFlavivirus Susceptibility in Aedes aegypti
Section snippets
Population Genetics of Aedes aegypti
Aedes aegypti has a cosmopolitan distribution between the 40°N and 40°S latitudes and is phenotypically polymorphic, varies in gene frequencies as detected by biochemical and molecular genetic markers, and exhibits variation in vector competence for arboviruses. In sub-Saharan Africa, Ae. aegypti appears as a black sylvan race or subspecies, Ae. aegypti formosus, that oviposits primarily in treeholes. A light-colored domestic race, Ae. aegypti aegypti is distributed in tropical and subtropical
Physiologic Genetics of Vector Competence
Figure 2 is a generalized diagram showing potential barriers to transmission that an arbovirus must overcome to be transmitted by a mosquito vector (22). Following ingestion in a bloodmeal, the arbovirus must first infect midgut epithelial cells of the vector. Presumably, virions interact with receptors on midgut epithelial cells and penetrate the cells. Uncoating, transcription, and translation of the virus genome is followed by virion maturation. Then, infectious virions must disseminate from
Environmental Factors Also Control Arbovirus Transmission
Biological transmission of arboviruses by a mosquito involves complex interactions among intrinsic biological factors in the mosquito and virus and extrinsic, environmental factors. Vector competence in an individual mosquito is a function of biological barriers discussed previously that an ingested virus must pass through to be replicated and finally transmitted. However, functioning of these barriers on a strictly deterministic basis would fail to explain the large variation in vector
Variation for Flavivirus Vector Competence in Aedes aegypti
Several studies have documented wide variation among and within populations of Ae. aegypti in vector competence for flaviviruses. Geographic variation in oral infection rates with YF was demonstrated among 28 populations of Ae. aegypti worldwide (33). Patterns of oral susceptibility correlated with the eight genetic groupings identified by allozyme analysis previously described (17). Least susceptible mosquitoes were from the sylvan formosus populations (7–34% with disseminated infection [DI]),
Quantitative Genetics of Vector Competence in Aedes aegypti
Quantitative genetics provides a useful tool for determining the degree to which a phenotypic trait is controlled by genetic and environmental factors. It also provides a means to determine the ways that alleles contribute to the phenotype. We have discussed that susceptibility to arboviruses appears to be under the control of multiple loci and subject to environmental effects. We performed a quantitative genetic study of the ability of Ae. aegypti to propagate DEN-2 in the midgut and in a
Mapping Genes That Control Flavivirus Vector Competence in Aedes aegypti
All research to date indicates that level of DEN infection in Ae. aegypti is a quantitative rather than a discrete variable appearing to be distributed continuously among individuals and subject to environmental effects. Recent molecular genetic and statistical advances permit mapping of loci affecting expression of quantitative traits, termed quantitative trait loci (QTL). Severson and colleagues 62, 63 mapped in Ae. aegypti the QTL that condition susceptibility to filarial worms (64) and
Genetics of Vector Competence in Aedes aegypti Populations
Information presented in this review suggests a general model for the dynamics of flavivirus vector competence in Ae. aegypti populations. Our results suggest that variation in dengue infection rates among natural populations of Ae. aegypti may be due to segregation of alleles at each of the three QTL. Differences in dengue susceptibility between Ae. aegypti aegypti and Ae. aegypti formosus populations may reflect differences in frequency of alleles at MIB and MEB loci but may also arise from
Identification of Genes Controlling Vector Competence in Aedes aegypti
Our results suggest that alleles at primarily three independently segregating loci create an MIB or MEB for flaviviruses in Ae. aegypti. Alleles at these loci act additively both within each QTL and independently among QTL. Other loci of minor effect may also be involved. The additive genetic pattern observed could reflect differences among genotypes in 1) density of a virus receptor on midgut cells, 2) abundance of intracellular factors needed for viral replication, or 3) abundance of
Acknowledgements
This research was supported by NIH grants U01AI45430 and R01-AI49256. NG-E was supported by NIH Fogarty Center Training grant D43 TW01130.
References (69)
- et al.
Urban yellow fever epidemic in western Nigeria, 1987
Trans R Soc Trop Med Hyg
(1989) - et al.
Epidemic yellow fever in eastern Nigeria, 1986
Lancet
(1988) - et al.
Expansion of epidemic dengue viral infections to Pakistan
Int J Infect Dis
(1998) - et al.
Role of La Crosse virus glycoproteins in attachment of virus to host cells
Virology
(1991) - et al.
Enzyme processing of La Crosse virus glycoprotein G1a bunyavirus-vector infection model
Virology
(1989) - et al.
Enhanced infectivity of modified bluetongue virus particles for two insect cell lines and for two Culicoides vector species
Virology
(1996) - et al.
Bunyavirus-vector interactions
Virus Res
(1988) - et al.
St. Louis encephalitis virusan ultrastructural study of infection in a mosquito vector
Virology
(1973) - et al.
Eastern equine encephalomyelitis virusan electron microscopic study of Aedes triseriatus (Say) salivary gland infection
Virology
(1971) - et al.
Increase in the size of the amino acid pool is sufficient to activate translation of early trypsin mRNA in Aedes aegypti midgut
Insect Biochem Mol Biol
(1999)
Neuroendocrine factors affecting the steady-state levels of early trypsin mRNA in Aedes aegypti
J Insect Physiol
Geographic distribution and evolution of yellow fever viruses based on direct sequencing of genomic cDNA fragments
J Gen Virol
Denguethe risk to developed and developing countries
Proc Natl Acad Sci USA
Vector-borne emergent disease
Ann NY Acad Sci
Epidemic yellow fever caused by an incompetent mosquito vector
Trop Med Parasitol
Reemergence of dengue in Cubaa 1997 epidemic in Santiago de Cuba
Emerg Infect Dis
Two contiguous outbreaks of dengue type 2 in north Queensland
Med J Aust
Emerging infectious diseases—Southeast Asia
Emerg Infect Dis
Dengue fever on the increase
Nat Med
Emerging and resurging vector-borne diseases
Annu Rev Entomol
Changing epidemiology of dengue hemorrhagic fever in Thailand
Epidemiol Infect
Dengue reemergence in Argentina
Emerg Infect Dis
The features of imported dengue fever cases from 1996 to 1999
Jpn J Infect Dis
The yellow fever mosquitoevolutionary genetics and arthropod-borne disease
Am Entomol
A world-wide survey of genetic variation in the yellow fever mosquito, Aedes aegypti
Genet Res
Population genetics with RAPD-PCR markersthe breeding structure of Aedes aegypti in Puerto Rico
Heredity
Genetic isolation by distance among Aedes aegypti populations along the northeastern coast of Mexico
Am J Trop Med Hyg
The breeding structure of Aedes aegypti populations in Mexico varies by region
Am J Trop Med Hyg
Macrogeographic genetic variation in a human commensalAedes aegypti, the yellow fever mosquito
Genet Res
Natural cycles of vector borne pathogens
VP7an attachment protein of bluetongue virus for cellular receptors in Culicoides variipennis
J Gen Virol
A putative receptor for Venezuelan equine encephalitis virus from mosquito cells
J Virol
Development of a Sindbis virus expression system that efficiently expresses green fluorescent protein in midguts of Aedes aegypti following per os infection
Insect Mol Biol
Quantitative trait loci that control vector competence for dengue-2 virus in the mosquito Aedes aegypti
Genetics
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