Limits...
Lineage divergence detected in the malaria vector Anopheles marajoara (Diptera: Culicidae) in Amazonian Brazil.

McKeon SN, Lehr MA, Wilkerson RC, Ruiz JF, Sallum MA, Lima JB, Povoa MM, Conn JE - Malar. J. (2010)

Bottom Line: COI sequences at the 3' end were more variable, demonstrating significant pairwise differentiation (3.82%) compared to the more moderate 2.92% detected by the Folmer region.Strong support for combined data with significant differentiation detected in the COI and absent in the nDNA suggest that the divergence is recent, and detectable only by the faster evolving mtDNA.Differences in demographic history and climatic changes may have contributed to mtDNA lineage divergence in A. marajoara.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Sciences, School of Public Health, State University of New York-Albany, Empire State Plaza, Albany, NY 12201 USA.

ABSTRACT

Background: Cryptic species complexes are common among anophelines. Previous phylogenetic analysis based on the complete mtDNA COI gene sequences detected paraphyly in the Neotropical malaria vector Anopheles marajoara. The "Folmer region" detects a single taxon using a 3% divergence threshold.

Methods: To test the paraphyletic hypothesis and examine the utility of the Folmer region, genealogical trees based on a concatenated (white + 3' COI sequences) dataset and pairwise differentiation of COI fragments were examined. The population structure and demographic history were based on partial COI sequences for 294 individuals from 14 localities in Amazonian Brazil. 109 individuals from 12 localities were sequenced for the nDNA white gene, and 57 individuals from 11 localities were sequenced for the ribosomal DNA (rDNA) internal transcribed spacer 2 (ITS2).

Results: Distinct A. marajoara lineages were detected by combined genealogical analysis and were also supported among COI haplotypes using a median joining network and AMOVA, with time since divergence during the Pleistocene (<100,000 ya). COI sequences at the 3' end were more variable, demonstrating significant pairwise differentiation (3.82%) compared to the more moderate 2.92% detected by the Folmer region. Lineage 1 was present in all localities, whereas lineage 2 was restricted mainly to the west. Mismatch distributions for both lineages were bimodal, likely due to multiple colonization events and spatial expansion (~798-81,045 ya). There appears to be gene flow within, not between lineages, and a partial barrier was detected near Rio Jari in Amapá state, separating western and eastern populations. In contrast, both nDNA data sets (white gene sequences with or without the retention of the 4th intron, and ITS2 sequences and length) detected a single A. marajoara lineage.

Conclusions: Strong support for combined data with significant differentiation detected in the COI and absent in the nDNA suggest that the divergence is recent, and detectable only by the faster evolving mtDNA. A within subgenus threshold of >2% may be more appropriate among sister taxa in cryptic anopheline complexes than the standard 3%. Differences in demographic history and climatic changes may have contributed to mtDNA lineage divergence in A. marajoara.

Show MeSH

Related in: MedlinePlus

Genealogical trees based on 52 haplotypes from 895-bp sequenced from 107 specimens of A. marajoara s.l. Bayesian Inference (BI) and Maximum parsimony (MP) trees based on the combined white + COI dataset. Branch support was estimated from 1,000 replicates of a bootstrap search (right tree) and posterior probability (left tree). Anopheles albimanus, was the out group. Lineage 2 haplotypes are indicated as L2.1-L2.16 and lineage 1 haplotypes as L1.1-L1.36. * Denotes samples from Marajo island, ~56 km from the A. marajoara type locality.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2959070&req=5

Figure 1: Genealogical trees based on 52 haplotypes from 895-bp sequenced from 107 specimens of A. marajoara s.l. Bayesian Inference (BI) and Maximum parsimony (MP) trees based on the combined white + COI dataset. Branch support was estimated from 1,000 replicates of a bootstrap search (right tree) and posterior probability (left tree). Anopheles albimanus, was the out group. Lineage 2 haplotypes are indicated as L2.1-L2.16 and lineage 1 haplotypes as L1.1-L1.36. * Denotes samples from Marajo island, ~56 km from the A. marajoara type locality.

Mentions: The estimated MP and BI trees, each with 42 parsimoniously informative sites, indicated two distinct lineages of A. marajoara with varying levels of support (Figure 1). The more derived lineage 1 remains ambiguous (only moderate support, 0.66 and 52%); however it does have the broadest distribution and contains samples from near (~56 km) the type locality on Marajó Island, Pará state, Brazil [79]. Lineage 2, in contrast, is more restricted geographically and has higher support (1.00 and 89%, Figure 1). The relatively low BI branch support (0.66) for A. marajoara lineage 1 coupled with the moderate support among some of the subdivisions suggests this lineage is paraphyletic and that haplotypes that would otherwise increase lineage support are missing (extinct or not sampled). Within both lineages, smaller subdivisions, not related to geography, were apparent between the haplotypes that are separated by seven mutations in lineage 1 (between haplotypes 11 and 13) and 10 mutations in lineage 2 (haplotypes 48 and 49), illustrated in the network (Figure 2).


Lineage divergence detected in the malaria vector Anopheles marajoara (Diptera: Culicidae) in Amazonian Brazil.

McKeon SN, Lehr MA, Wilkerson RC, Ruiz JF, Sallum MA, Lima JB, Povoa MM, Conn JE - Malar. J. (2010)

Genealogical trees based on 52 haplotypes from 895-bp sequenced from 107 specimens of A. marajoara s.l. Bayesian Inference (BI) and Maximum parsimony (MP) trees based on the combined white + COI dataset. Branch support was estimated from 1,000 replicates of a bootstrap search (right tree) and posterior probability (left tree). Anopheles albimanus, was the out group. Lineage 2 haplotypes are indicated as L2.1-L2.16 and lineage 1 haplotypes as L1.1-L1.36. * Denotes samples from Marajo island, ~56 km from the A. marajoara type locality.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2959070&req=5

Figure 1: Genealogical trees based on 52 haplotypes from 895-bp sequenced from 107 specimens of A. marajoara s.l. Bayesian Inference (BI) and Maximum parsimony (MP) trees based on the combined white + COI dataset. Branch support was estimated from 1,000 replicates of a bootstrap search (right tree) and posterior probability (left tree). Anopheles albimanus, was the out group. Lineage 2 haplotypes are indicated as L2.1-L2.16 and lineage 1 haplotypes as L1.1-L1.36. * Denotes samples from Marajo island, ~56 km from the A. marajoara type locality.
Mentions: The estimated MP and BI trees, each with 42 parsimoniously informative sites, indicated two distinct lineages of A. marajoara with varying levels of support (Figure 1). The more derived lineage 1 remains ambiguous (only moderate support, 0.66 and 52%); however it does have the broadest distribution and contains samples from near (~56 km) the type locality on Marajó Island, Pará state, Brazil [79]. Lineage 2, in contrast, is more restricted geographically and has higher support (1.00 and 89%, Figure 1). The relatively low BI branch support (0.66) for A. marajoara lineage 1 coupled with the moderate support among some of the subdivisions suggests this lineage is paraphyletic and that haplotypes that would otherwise increase lineage support are missing (extinct or not sampled). Within both lineages, smaller subdivisions, not related to geography, were apparent between the haplotypes that are separated by seven mutations in lineage 1 (between haplotypes 11 and 13) and 10 mutations in lineage 2 (haplotypes 48 and 49), illustrated in the network (Figure 2).

Bottom Line: COI sequences at the 3' end were more variable, demonstrating significant pairwise differentiation (3.82%) compared to the more moderate 2.92% detected by the Folmer region.Strong support for combined data with significant differentiation detected in the COI and absent in the nDNA suggest that the divergence is recent, and detectable only by the faster evolving mtDNA.Differences in demographic history and climatic changes may have contributed to mtDNA lineage divergence in A. marajoara.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Sciences, School of Public Health, State University of New York-Albany, Empire State Plaza, Albany, NY 12201 USA.

ABSTRACT

Background: Cryptic species complexes are common among anophelines. Previous phylogenetic analysis based on the complete mtDNA COI gene sequences detected paraphyly in the Neotropical malaria vector Anopheles marajoara. The "Folmer region" detects a single taxon using a 3% divergence threshold.

Methods: To test the paraphyletic hypothesis and examine the utility of the Folmer region, genealogical trees based on a concatenated (white + 3' COI sequences) dataset and pairwise differentiation of COI fragments were examined. The population structure and demographic history were based on partial COI sequences for 294 individuals from 14 localities in Amazonian Brazil. 109 individuals from 12 localities were sequenced for the nDNA white gene, and 57 individuals from 11 localities were sequenced for the ribosomal DNA (rDNA) internal transcribed spacer 2 (ITS2).

Results: Distinct A. marajoara lineages were detected by combined genealogical analysis and were also supported among COI haplotypes using a median joining network and AMOVA, with time since divergence during the Pleistocene (<100,000 ya). COI sequences at the 3' end were more variable, demonstrating significant pairwise differentiation (3.82%) compared to the more moderate 2.92% detected by the Folmer region. Lineage 1 was present in all localities, whereas lineage 2 was restricted mainly to the west. Mismatch distributions for both lineages were bimodal, likely due to multiple colonization events and spatial expansion (~798-81,045 ya). There appears to be gene flow within, not between lineages, and a partial barrier was detected near Rio Jari in Amapá state, separating western and eastern populations. In contrast, both nDNA data sets (white gene sequences with or without the retention of the 4th intron, and ITS2 sequences and length) detected a single A. marajoara lineage.

Conclusions: Strong support for combined data with significant differentiation detected in the COI and absent in the nDNA suggest that the divergence is recent, and detectable only by the faster evolving mtDNA. A within subgenus threshold of >2% may be more appropriate among sister taxa in cryptic anopheline complexes than the standard 3%. Differences in demographic history and climatic changes may have contributed to mtDNA lineage divergence in A. marajoara.

Show MeSH
Related in: MedlinePlus