Limits...
French invasive Asian tiger mosquito populations harbor reduced bacterial microbiota and genetic diversity compared to Vietnamese autochthonous relatives.

Minard G, Tran FH, Van VT, Goubert C, Bellet C, Lambert G, Kim KL, Thuy TH, Mavingui P, Valiente Moro C - Front Microbiol (2015)

Bottom Line: The insect-associated microbiota is now recognized to play a significant role in host biology.Overall genetic diversities of both hosts and bacterial microbiota were significantly reduced in recently established populations of France compared to the autochthonous populations of Vietnam.These results open up many important avenues of investigation in order to link the process of geographical invasion to shifts in commensal and symbiotic microbiome communities, as such shifts may have dramatic impacts on the biology and/or vector competence of invading hematophagous insects.

View Article: PubMed Central - PubMed

Affiliation: Ecologie Microbienne, UMR Centre National de la Recherche Scientifique 5557, USC INRA 1364, VetAgro Sup, FR41 BioEnvironment and Health, Université Claude Bernard Lyon 1 Villeurbanne, France.

ABSTRACT
The Asian tiger mosquito Aedes albopictus is one of the most significant pathogen vectors of the twenty-first century. Originating from Asia, it has invaded a wide range of eco-climatic regions worldwide. The insect-associated microbiota is now recognized to play a significant role in host biology. While genetic diversity bottlenecks are known to result from biological invasions, the resulting shifts in host-associated microbiota diversity has not been thoroughly investigated. To address this subject, we compared four autochthonous Ae. albopictus populations in Vietnam, the native area of Ae. albopictus, and three populations recently introduced to Metropolitan France, with the aim of documenting whether these populations display differences in host genotype and bacterial microbiota. Population-level genetic diversity (microsatellite markers and COI haplotype) and bacterial diversity (16S rDNA metabarcoding) were compared between field-caught mosquitoes. Bacterial microbiota from the whole insect bodies were largely dominated by Wolbachia pipientis. Targeted analysis of the gut microbiota revealed a greater bacterial diversity in which a fraction was common between French and Vietnamese populations. The genus Dysgonomonas was the most prevalent and abundant across all studied populations. Overall genetic diversities of both hosts and bacterial microbiota were significantly reduced in recently established populations of France compared to the autochthonous populations of Vietnam. These results open up many important avenues of investigation in order to link the process of geographical invasion to shifts in commensal and symbiotic microbiome communities, as such shifts may have dramatic impacts on the biology and/or vector competence of invading hematophagous insects.

No MeSH data available.


Genetic structures of Aedes albopictus populations. The map of the microsatellite genetic structure (K = 2) for each site. Each bar represents an individual and the grayscale represents the probability that an individual belongs to a population. Scale bar of the maps, 200 km. NC, Nice; PLV, Porte-lès-Valence; SP, Saint Priest; VT, Vung Tàu City; HCM, Hồ Chí Minh City; BD, Bình Du'o'ng; BGM, Bù Gia Mâp.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4585046&req=5

Figure 5: Genetic structures of Aedes albopictus populations. The map of the microsatellite genetic structure (K = 2) for each site. Each bar represents an individual and the grayscale represents the probability that an individual belongs to a population. Scale bar of the maps, 200 km. NC, Nice; PLV, Porte-lès-Valence; SP, Saint Priest; VT, Vung Tàu City; HCM, Hồ Chí Minh City; BD, Bình Du'o'ng; BGM, Bù Gia Mâp.

Mentions: The mosquito nuclear genomic variation was characterized further by genotyping 199 individuals with 11 microsatellite markers. The overall number of alleles per locus varied from 6 (AealbB52) to 30 (Alb-tri 18). Rarefied allele richness of populations from each site was 4.56 for SP, 4.57 for PLV, 5.91 for NC, 6.50 for HCM, 7.47 for VT, 8.25 for BGM, and 8.62 for BD. To test for hypothetical population bottlenecks or expansions, the allelic richness (Ar) and the heterozygosity (He) at each genomic locus were analyzed for each sampling site. For both these analyses of variation, values for populations from France were significantly lower than those from Vietnam (Mann–Whitney, p = 0.0003 and 0.0003, respectively). The bottleneck analysis did not show any significant heterozygosity excess under a two-phase model or a single stepwise model (Table S5). No significant linkage disequilibrium was found between any pair of loci. All populations had a positive inbreeding index (FIS) between 0.12 (for PLV) and 0.196 (for HCM) reflecting an excess of homozygotes (Table 2). Moreover, there were significant scores for the presence of alleles. However, FST values of the entire mosquito sample were 0.142 (CI95% 0.058–0.269) with ENA correction for alleles and 0.145 (CI95% 0.061–0.270) without correction. Consequently, the presence of alleles did not strongly impact the estimation of differentiation. The structure of the populations was evaluated with the Bayesian method of assignment. The optimal number of clusters selected with the second-order change in likelihood method was K = 2 (Figure S1) (Evanno et al., 2005). Populations were clustered in two different genetic groups according to country of origin, except for populations from PLV in France and BD in Vietnam, which harbored a mixture of both genotypes (Figure 5, Figure S5). AMOVA analysis revealed a non-significant variation in the structure among countries (AMOVA 2.6%, p = 0.2) but a moderate variation among sites within a country (AMOVA 13%, p < 10−3) (Table 1).


French invasive Asian tiger mosquito populations harbor reduced bacterial microbiota and genetic diversity compared to Vietnamese autochthonous relatives.

Minard G, Tran FH, Van VT, Goubert C, Bellet C, Lambert G, Kim KL, Thuy TH, Mavingui P, Valiente Moro C - Front Microbiol (2015)

Genetic structures of Aedes albopictus populations. The map of the microsatellite genetic structure (K = 2) for each site. Each bar represents an individual and the grayscale represents the probability that an individual belongs to a population. Scale bar of the maps, 200 km. NC, Nice; PLV, Porte-lès-Valence; SP, Saint Priest; VT, Vung Tàu City; HCM, Hồ Chí Minh City; BD, Bình Du'o'ng; BGM, Bù Gia Mâp.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4585046&req=5

Figure 5: Genetic structures of Aedes albopictus populations. The map of the microsatellite genetic structure (K = 2) for each site. Each bar represents an individual and the grayscale represents the probability that an individual belongs to a population. Scale bar of the maps, 200 km. NC, Nice; PLV, Porte-lès-Valence; SP, Saint Priest; VT, Vung Tàu City; HCM, Hồ Chí Minh City; BD, Bình Du'o'ng; BGM, Bù Gia Mâp.
Mentions: The mosquito nuclear genomic variation was characterized further by genotyping 199 individuals with 11 microsatellite markers. The overall number of alleles per locus varied from 6 (AealbB52) to 30 (Alb-tri 18). Rarefied allele richness of populations from each site was 4.56 for SP, 4.57 for PLV, 5.91 for NC, 6.50 for HCM, 7.47 for VT, 8.25 for BGM, and 8.62 for BD. To test for hypothetical population bottlenecks or expansions, the allelic richness (Ar) and the heterozygosity (He) at each genomic locus were analyzed for each sampling site. For both these analyses of variation, values for populations from France were significantly lower than those from Vietnam (Mann–Whitney, p = 0.0003 and 0.0003, respectively). The bottleneck analysis did not show any significant heterozygosity excess under a two-phase model or a single stepwise model (Table S5). No significant linkage disequilibrium was found between any pair of loci. All populations had a positive inbreeding index (FIS) between 0.12 (for PLV) and 0.196 (for HCM) reflecting an excess of homozygotes (Table 2). Moreover, there were significant scores for the presence of alleles. However, FST values of the entire mosquito sample were 0.142 (CI95% 0.058–0.269) with ENA correction for alleles and 0.145 (CI95% 0.061–0.270) without correction. Consequently, the presence of alleles did not strongly impact the estimation of differentiation. The structure of the populations was evaluated with the Bayesian method of assignment. The optimal number of clusters selected with the second-order change in likelihood method was K = 2 (Figure S1) (Evanno et al., 2005). Populations were clustered in two different genetic groups according to country of origin, except for populations from PLV in France and BD in Vietnam, which harbored a mixture of both genotypes (Figure 5, Figure S5). AMOVA analysis revealed a non-significant variation in the structure among countries (AMOVA 2.6%, p = 0.2) but a moderate variation among sites within a country (AMOVA 13%, p < 10−3) (Table 1).

Bottom Line: The insect-associated microbiota is now recognized to play a significant role in host biology.Overall genetic diversities of both hosts and bacterial microbiota were significantly reduced in recently established populations of France compared to the autochthonous populations of Vietnam.These results open up many important avenues of investigation in order to link the process of geographical invasion to shifts in commensal and symbiotic microbiome communities, as such shifts may have dramatic impacts on the biology and/or vector competence of invading hematophagous insects.

View Article: PubMed Central - PubMed

Affiliation: Ecologie Microbienne, UMR Centre National de la Recherche Scientifique 5557, USC INRA 1364, VetAgro Sup, FR41 BioEnvironment and Health, Université Claude Bernard Lyon 1 Villeurbanne, France.

ABSTRACT
The Asian tiger mosquito Aedes albopictus is one of the most significant pathogen vectors of the twenty-first century. Originating from Asia, it has invaded a wide range of eco-climatic regions worldwide. The insect-associated microbiota is now recognized to play a significant role in host biology. While genetic diversity bottlenecks are known to result from biological invasions, the resulting shifts in host-associated microbiota diversity has not been thoroughly investigated. To address this subject, we compared four autochthonous Ae. albopictus populations in Vietnam, the native area of Ae. albopictus, and three populations recently introduced to Metropolitan France, with the aim of documenting whether these populations display differences in host genotype and bacterial microbiota. Population-level genetic diversity (microsatellite markers and COI haplotype) and bacterial diversity (16S rDNA metabarcoding) were compared between field-caught mosquitoes. Bacterial microbiota from the whole insect bodies were largely dominated by Wolbachia pipientis. Targeted analysis of the gut microbiota revealed a greater bacterial diversity in which a fraction was common between French and Vietnamese populations. The genus Dysgonomonas was the most prevalent and abundant across all studied populations. Overall genetic diversities of both hosts and bacterial microbiota were significantly reduced in recently established populations of France compared to the autochthonous populations of Vietnam. These results open up many important avenues of investigation in order to link the process of geographical invasion to shifts in commensal and symbiotic microbiome communities, as such shifts may have dramatic impacts on the biology and/or vector competence of invading hematophagous insects.

No MeSH data available.