Population genetic structure of the major malaria vector Anopheles darlingi (Diptera: Culicidae) from the Brazilian Amazon, using microsatellite markers
Mem. Inst. Oswaldo Cruz
;
102(3): 319-328, June 2007. tab, mapas
Article
in English
| LILACS
| ID: lil-452509
ABSTRACT
The population genetic structure of Anopheles darlingi, the major human malaria vector in the Neotropics, was examined using seven microsatellite loci from nine localities in central and western Amazonian Brazil. High levels of genetic variability were detected (5-25 alleles per locus; H E = 0.519-0.949). There was deviation from Hardy-Weinberg Equilibrium for 59.79 percent of the tests due to heterozygote deficits, while the analysis of linkage disequilibrium was significant for only two of 189 (1.05 percent) tests, most likely caused by null alleles. Genetic differentiation (F ST = 0.001-0.095; Nm = 4.7-363.8) indicates that gene flow is extensive among locations < 152 km apart (with two exceptions) and reduced, but not absent, at a larger geographic scale. Genetic and geographic distances were significantly correlated (R² = 0.893, P < 0.0002), supporting the isolation by distance (IBD) model. The overall estimate of Ne was 202.4 individuals under the linkage disequilibrium model, and 8 under the heterozygote excess model. Analysis of molecular variance showed that nearly all variation (~ 94 percent) was within sample locations. The UPGMA phenogram clustered the samples geographically, with one branch including 5/6 of the state of Amazonas localities and the other branch the Acre, Rondônia, and remaining Amazonas localities. Taken together, these data suggest little genetic structure for An. darlingi from central and western Amazonian Brazil. These findings also imply that the IBD model explains nearly all of the differentiation detected. In practical terms, populations of An. darlingi at distances < 152 km should respond similarly to vector control measures, because of high gene flow.
Full text:
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Index:
LILACS (Americas)
Main subject:
Genetic Variation
/
Microsatellite Repeats
/
Genetics, Population
/
Insect Vectors
/
Anopheles
Type of study:
Prognostic study
Limits:
Animals
/
Humans
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Mem. Inst. Oswaldo Cruz
Journal subject:
Tropical Medicine
/
Parasitology
Year:
2007
Type:
Article
/
Project document
Affiliation country:
Brazil
/
United States
Institution/Affiliation country:
Instituto Nacional de Pesquisas da Amazônia/BR
/
New York State Department of Health/US
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