Patterns of genetic divergence among populations of Aedes aegypti L. (Diptera: Culicidae) in the southeastern USA

Abstract

BackgroundThe yellow fever mosquito, Aedes aegypti is a public health concern in the USA, especially in the wake of emergent diseases such as Zika and chikungunya. Aedes aegypti populations dwindled after the invasion of Aedes albopictus in the 1980s and many populations were extirpated. However, in some areas Ae. aegypti persisted in small populations and there are reports of recent resurgences of Ae. aegypti in Florida, Louisiana, Nevada and California. We assessed the population genetic structure of Ae. aegypti in Florida and Georgia, which has concomitant consequences related to mosquito dispersal, pesticide resistance and vectorial capacity.MethodsWe collected Ae. aegypti across Florida and in Georgia using ovitraps. We hatched the eggs and reared them to adults, and after sacrifice we extracted their DNA. We then probed each individual for variation in 6 microsatellite markers, which we used to address population genetic characteristics.ResultsWe collected Ae. aegypti and genotyped seven Florida populations and one Georgia population using microsatellite markers. We found evidence of isolation by distance model of gene flow supported by driving distance among cities within Florida and two theoretic genetic clusters.ConclusionsSignificant genetic structure between some populations with substantial gene flow between geographically distant cities suggests regional genetic structuring of Ae. aegypti in Florida. This study provides information on the genetic exchange between populations of Ae. aegypti in the southeastern USA and suggests potential routes of spread of this species.

Sunshine versus gold: The effect of population age on genetic structure of an invasive mosquito

“…This work builds on previous studies from Florida and southern California by increasing the number of individuals and sites sampled, as well as the number of genetic markers. Our work supports previous findings of minimal structure (Damal et al., 2013) and a high degree of admixture in Florida (Hopperstad et al., 2019). Unlike a previous study, we find almost no evidence of Isolation by Distance in Florida (Hopperstad et al., 2019).…”

“…Our work supports previous findings of minimal structure (Damal et al., 2013) and a high degree of admixture in Florida (Hopperstad et al., 2019). Unlike a previous study, we find almost no evidence of Isolation by Distance in Florida (Hopperstad et al., 2019). Additionally, a geographically limited study found significant differentiation among four Florida populations (Apopka, Kissimmee, Fort Myers, and Key West) using ddRADseq (Burford Reiskind et al., 2018).…”

“…aegypti genetic diversity and structure in Florida show a variable amount of genetic differentiation across the state. Using mitochondrial DNA, Damal et al find no differentiation between the east and west coast of Florida, whereas Hopperstad et al report the opposite result using nine microsatellites (although with a high amount of admixture within most of the groups; Damal, Murrell, Juliano, Conn, & Loes, 2013; Hopperstad, Reiskind, Labadie, & Reiskind, 2019). Using ddRADseq, Burford Reiskind, Labadie, Bargielowski, Lounibos, and Reiskind (2018) show differentiation between the four Florida populations included in their analysis.…”

Population structure and ancestry prediction of Aedes aegypti (Diptera: Culicidae) supports a single African origin of Colombian populations

“…Some recent examples of Ae. aegypti microgeographic population structure in the Americas has disclosed diverse population dynamics (i.e., migration and diversity) is placed in eclectic ecogeographical regions such as boat traffic driving migration in Peruvian Amazon, (5) the substantial gene flow between geographically distant cities in Florida connected by an Interstate Highway, (7,8) and the recently multiple-source invasion of diverse populations into California, (9,10) and in several regions of Brazil. (11,12,13) In Colombia, a first study based on random amplified polymorphic DNA-polymerase chain reaction products analysis (RAPD) reported local genetic population substructure in city of Cali, which was suggested involved in differences of vector competence and insecticide resistance ratios.…”

“…aegypti populations demography, using nuclear genetic information such as polymorphic microsatellite loci and genome-wide single nucleotide polymorphisms (SNPs) approach, unveiled lack genetic concordance between differentiation patterns observed at nuclear genetic level and East, and West African mitochondrial related populations. (4,7,10,24,25) In this sense, considering that SNPs and polymorphic microsatellite loci markers have higher genetic resolution (i.e., faster mutation rate) than mitochondrial markers, the observed mitochondrial lineage polymorphisms picture is thought occurred previous to outside Africa dis-persal, and New World populations were originated by a single source from a mitochondrial polymorphic African ancient around the 16th-century, as consequence of slave trade between Africa and Americas. (4,24) Due no comprehensive evidence for population structure of Colombian Ae.…”