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Adopting Bacteria in Order to Adapt to Water-How Reed Beetles Colonized the Wetlands (Coleoptera, Chrysomelidae, Donaciinae).

Kleinschmidt B, Kölsch G - Insects (2011)

Bottom Line: Reed beetles are herbivores living on wetland plants, each species being mono- or oligo-phagous.They lay their eggs on the host plant and the larvae live underwater in the sediment attached to its roots.The pupation underwater enabled the reed beetles to permanently colonize the wetlands and to diversify in this habitat underexploited by herbivorous insects (adaptive radiation).

View Article: PubMed Central - PubMed

Affiliation: Zoological Institute, Molecular Evolutionary Biology, University of Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany. birgit.kleinschmidt@gmx.net.

ABSTRACT
The present paper reviews the biology of reed beetles (Donaciinae), presents experimental data on the role of specific symbiotic bacteria, and describes a molecular method for the detection of those bacteria. Reed beetles are herbivores living on wetland plants, each species being mono- or oligo-phagous. They lay their eggs on the host plant and the larvae live underwater in the sediment attached to its roots. The larvae pupate there in a water-tight cocoon, which they build using a secretion that is produced by symbiotic bacteria. The bacteria are located in four blind sacs at the foregut of the larvae; in (female) adults they colonize two out of the six Malpighian tubules. Tetracycline treatment of larvae reduced their pupation rate, although the bacteria could not be fully eliminated. When the small amount of bacterial mass attached to eggs was experimentally removed before hatching, symbiont free larvae resulted, showing the external transmission of the bacteria to the offspring. Specific primers were designed to detect the bacteria, and to confirm their absence in manipulated larvae. The pupation underwater enabled the reed beetles to permanently colonize the wetlands and to diversify in this habitat underexploited by herbivorous insects (adaptive radiation).

No MeSH data available.


Related in: MedlinePlus

Co-cladogenesis of symbiotic bacteria and their reed beetle hosts. (a) Profile of the margin of a water body with characteristic vegetation; (b) Phylogenetic tree of the symbionts; (c) Phylogenetic tree of the hosts (reed beetles); (d) Congruent branching pattern within the Sparganium-group. The trees in (b) and (c) are schematic representations of the phylogenies presented in greater detail in [45]. The size of the triangles (length of vertical edge) is proportional to the number of species that had been included in that analysis (for scale: five species in the Sparganium-group). The species groups (names given between (b) and (c) and the position of four single species varying between methods used for tree construction are discussed in [55]. The position of the groups relative to the shore profile in (a) reflects their approximate habitat preference.
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f7-insects-02-00540: Co-cladogenesis of symbiotic bacteria and their reed beetle hosts. (a) Profile of the margin of a water body with characteristic vegetation; (b) Phylogenetic tree of the symbionts; (c) Phylogenetic tree of the hosts (reed beetles); (d) Congruent branching pattern within the Sparganium-group. The trees in (b) and (c) are schematic representations of the phylogenies presented in greater detail in [45]. The size of the triangles (length of vertical edge) is proportional to the number of species that had been included in that analysis (for scale: five species in the Sparganium-group). The species groups (names given between (b) and (c) and the position of four single species varying between methods used for tree construction are discussed in [55]. The position of the groups relative to the shore profile in (a) reflects their approximate habitat preference.

Mentions: The vertical transmission from female to offspring makes horizontal transfer of bacteria between species or via the environment highly unlikely, if not impossible. Since this association has existed since the origin of the reed beetles (see below), hosts and symbionts share 75–100 million years of common history. The consequence is a pattern of strict co-cladogenesis (Figure 7). The congruence of the phylogenetic trees is not simply a superficial resemblance, but it extends to the very twigs of the trees, as exemplified by the species group occurring on bur-reed (Sparganium; Figure 7d). Co-cladogenesis is characteristic of the ancient accociations between insects and their primary endosymbionts [49,50]. We do not use the term co-evolution in this context [51,52], because it is not possible to provide evidence for a pattern of adaptations and counter adaptations that would be characteristic of co-evolution in the strict sense [53]. The term co-speciation, as used by Kölsch and Pedersen [45], implies—as pointed out by the authors—that one assumes species status not only for the beetle taxa, but also for the respective bacterial symbionts. This approach appears justified given the consistent genetic differences (16S sequences; [45]) and was followed in the formal description of two symbiont species from two Macroplea species [39]. Further characterization of the symbionts for example by multi-locus sequence typing/analysis (MLST; [54]) would shed more light on this aspect.


Adopting Bacteria in Order to Adapt to Water-How Reed Beetles Colonized the Wetlands (Coleoptera, Chrysomelidae, Donaciinae).

Kleinschmidt B, Kölsch G - Insects (2011)

Co-cladogenesis of symbiotic bacteria and their reed beetle hosts. (a) Profile of the margin of a water body with characteristic vegetation; (b) Phylogenetic tree of the symbionts; (c) Phylogenetic tree of the hosts (reed beetles); (d) Congruent branching pattern within the Sparganium-group. The trees in (b) and (c) are schematic representations of the phylogenies presented in greater detail in [45]. The size of the triangles (length of vertical edge) is proportional to the number of species that had been included in that analysis (for scale: five species in the Sparganium-group). The species groups (names given between (b) and (c) and the position of four single species varying between methods used for tree construction are discussed in [55]. The position of the groups relative to the shore profile in (a) reflects their approximate habitat preference.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4553447&req=5

f7-insects-02-00540: Co-cladogenesis of symbiotic bacteria and their reed beetle hosts. (a) Profile of the margin of a water body with characteristic vegetation; (b) Phylogenetic tree of the symbionts; (c) Phylogenetic tree of the hosts (reed beetles); (d) Congruent branching pattern within the Sparganium-group. The trees in (b) and (c) are schematic representations of the phylogenies presented in greater detail in [45]. The size of the triangles (length of vertical edge) is proportional to the number of species that had been included in that analysis (for scale: five species in the Sparganium-group). The species groups (names given between (b) and (c) and the position of four single species varying between methods used for tree construction are discussed in [55]. The position of the groups relative to the shore profile in (a) reflects their approximate habitat preference.
Mentions: The vertical transmission from female to offspring makes horizontal transfer of bacteria between species or via the environment highly unlikely, if not impossible. Since this association has existed since the origin of the reed beetles (see below), hosts and symbionts share 75–100 million years of common history. The consequence is a pattern of strict co-cladogenesis (Figure 7). The congruence of the phylogenetic trees is not simply a superficial resemblance, but it extends to the very twigs of the trees, as exemplified by the species group occurring on bur-reed (Sparganium; Figure 7d). Co-cladogenesis is characteristic of the ancient accociations between insects and their primary endosymbionts [49,50]. We do not use the term co-evolution in this context [51,52], because it is not possible to provide evidence for a pattern of adaptations and counter adaptations that would be characteristic of co-evolution in the strict sense [53]. The term co-speciation, as used by Kölsch and Pedersen [45], implies—as pointed out by the authors—that one assumes species status not only for the beetle taxa, but also for the respective bacterial symbionts. This approach appears justified given the consistent genetic differences (16S sequences; [45]) and was followed in the formal description of two symbiont species from two Macroplea species [39]. Further characterization of the symbionts for example by multi-locus sequence typing/analysis (MLST; [54]) would shed more light on this aspect.

Bottom Line: Reed beetles are herbivores living on wetland plants, each species being mono- or oligo-phagous.They lay their eggs on the host plant and the larvae live underwater in the sediment attached to its roots.The pupation underwater enabled the reed beetles to permanently colonize the wetlands and to diversify in this habitat underexploited by herbivorous insects (adaptive radiation).

View Article: PubMed Central - PubMed

Affiliation: Zoological Institute, Molecular Evolutionary Biology, University of Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany. birgit.kleinschmidt@gmx.net.

ABSTRACT
The present paper reviews the biology of reed beetles (Donaciinae), presents experimental data on the role of specific symbiotic bacteria, and describes a molecular method for the detection of those bacteria. Reed beetles are herbivores living on wetland plants, each species being mono- or oligo-phagous. They lay their eggs on the host plant and the larvae live underwater in the sediment attached to its roots. The larvae pupate there in a water-tight cocoon, which they build using a secretion that is produced by symbiotic bacteria. The bacteria are located in four blind sacs at the foregut of the larvae; in (female) adults they colonize two out of the six Malpighian tubules. Tetracycline treatment of larvae reduced their pupation rate, although the bacteria could not be fully eliminated. When the small amount of bacterial mass attached to eggs was experimentally removed before hatching, symbiont free larvae resulted, showing the external transmission of the bacteria to the offspring. Specific primers were designed to detect the bacteria, and to confirm their absence in manipulated larvae. The pupation underwater enabled the reed beetles to permanently colonize the wetlands and to diversify in this habitat underexploited by herbivorous insects (adaptive radiation).

No MeSH data available.


Related in: MedlinePlus