Heike Hadrys - Academia.edu (original) (raw)

Papers by Heike Hadrys

Berliner und Münchener tierärztliche Wochenschrift

In zoonosis research only correct assigned host-agent-vector associations can lead to success. If... more In zoonosis research only correct assigned host-agent-vector associations can lead to success. If most biological species on Earth, from agent to host and from procaryotes to vertebrates, are still undetected, the development of a reliable and universal diversity detection tool becomes a conditio sine qua non. In this context, in breathtaking speed, modern molecular-genetic techniques have become acknowledged tools for the classification of life forms at all taxonomic levels. While previous DNA-barcoding techniques were criticised for several reasons (Moritz and Cicero, 2004; Rubinoff et al., 2006a, b; Rubinoff, 2006; Rubinoff and Haines, 2006) a new approach, the so called CAOS-barcoding (Character Attribute Organisation System), avoids most of the weak points. Traditional DNA-barcoding approaches are based on distances, i. e. they use genetic distances and tree construction algorithms for the classification of species or lineages. The definition of limit values is enforced and pro...

BMC Evolutionary Biology, 2009

Background: Whenever different data sets arrive at conflicting phylogenetic hypotheses, only test... more Background: Whenever different data sets arrive at conflicting phylogenetic hypotheses, only testable causal explanations of sources of errors in at least one of the data sets allow us to critically choose among the conflicting hypotheses of relationships. The large (28S) and small (18S) subunit rRNAs are among the most popular markers for studies of deep phylogenies. However, some nodes supported by this data are suspected of being artifacts caused by peculiarities of the evolution of these molecules. Arthropod phylogeny is an especially controversial subject dotted with conflicting hypotheses which are dependent on data set and method of reconstruction. We assume that phylogenetic analyses based on these genes can be improved further i) by enlarging the taxon sample and ii) employing more realistic models of sequence evolution incorporating nonstationary substitution processes and iii) considering covariation and pairing of sites in rRNA-genes.

One of the most widely distributed dragonfly species in Africa is the red-veined-dropwing Trithem... more One of the most widely distributed dragonfly species in Africa is the red-veined-dropwing Trithemis arteriosa. It is an indicator for permanent water bodies, which are freshwater ecosystems of high environmental value especially in arid regions. For studies to determine population structures, assess species viability and monitor environmental changes, a panel of 10 polymorphic microsatellite loci was developed. The number of alleles per locus ranged from four to 12, with an observed heterozygosity ranging from 0.149 to 0.843.

Heredity, 2012

It has been postulated that obligate asexual lineages may persist in the long term if they escape... more It has been postulated that obligate asexual lineages may persist in the long term if they escape from negative interactions with either sexual lineages or biological enemies; and thus, parthenogenetic populations will be more likely to occur in places that are difficult for sexuals to colonize, or those in which biological interactions are rare, such as islands or island-like habitats. Ischnura hastata is the only known example of natural parthenogenesis within the insect order Odonata, and it represents also a typical example of geographic parthenogenesis, as sexual populations are widely distributed in North America, whereas parthenogenetic populations of this species have only been found at the Azores archipelago. In order to gain insight in the origin and distribution of parthenogenetic I. hastata lineages, we have used microsatellites, mitochondrial and nuclear DNA sequence data, to examine the population genetic structure of this species over a wide geographic area. Our resul...

Molecular Phylogenetics and Evolution, 2010

Pterygota are traditionally divided in two lineages, the ''Palaeoptera" and Neoptera. Despite sev... more Pterygota are traditionally divided in two lineages, the ''Palaeoptera" and Neoptera. Despite several efforts neither morphology nor molecular systematics have resolved the phylogeny of the pterygote insects. Too few markers have yet been identified for adequately tracking mesozoic-aged divergences. We tested the Elongation factor-1a for its phylogenetic value in pterygote insect systematics. This highly conserved nuclear protein-coding gene has previously been reported to be useful in other groups for phylogenetic analyses at the intraordinal level as well as at the interordinal level. The analyses suggest that EF-1a DNA sequences as well as intron positions provide informative markers for pterygote phylogenetics.

Molecular Phylogenetics and Evolution, 2013

With respect to bauplan radiation, species and taxa richness, hexapods have an unassailable lead.... more With respect to bauplan radiation, species and taxa richness, hexapods have an unassailable lead. But still, the phylogenetic relationships among the orders and infraorders remain a matter of discussion. The rapidly increasing mitochondrial genome sequences from diverse insect species provide the opportunity to explore miscellaneous evolutionary questions in the superclass Hexapoda. A combined primary sequence analyses of the complete available data set has not yet been performed. Until now phylogenetic analyses of subsets of selected taxa resulted to strong supported topologies showing in some instances discrepancies between morphological and nuclear data. This circumstance started the discussion about the limits of complete mitochondrial genomes for inferring deep hexapod relationships. By using the hitherto densest taxon sampling of Hexapoda our analyses resulted in discrepancies to the current phylogenetic hypotheses based on morphological and nuclear data, e.g. monophyly of hexapods and some hexapods orders, e.g. Diptera, Hemiptera and Orthoptera. Nonetheless, compared to previously published studies that strongly support systematically erroneous groups using a sparse taxon sampling, our analyses had no support for theses discrepancies. Consequently, we highly recommend interpreting mt-genome based phylogenies with incomplete representation of major orders/taxa particularly for hexapods with cautions although the inferred relationships are highly supported.

Molecular Ecology Resources, 2013

The mitochondrial CO1 gene (cytochrome c oxidase I) is a widely accepted metazoan barcode region.... more The mitochondrial CO1 gene (cytochrome c oxidase I) is a widely accepted metazoan barcode region. In insects, the mitochondrial NADH dehydrogenase subunit 1 (ND1) gene region has proved to be another suitable marker especially for the identification of lower level taxonomic entities such as populations and sister species. To evaluate the potential of distance-based thresholds and character-based DNA barcoding for the identification of problematic species-rich taxa, both markers, CO1 and ND1, were used as test parameters in odonates. We sequenced and compared gene fragments of CO1 and ND1 for 271 odonate individuals representing 51 species, 22 genera and eight families. Our data suggests that (i) the combination of the CO1 and ND1 fragment forms a better identifier than a single region alone; and (ii) the character-based approach provides higher resolution than the distance-based method in Odonata especially in closely related taxonomic entities.

Genome Biology and Evolution, 2012

The evolution of the diverse insect lineages is one of the most fascinating issues in evolutionar... more The evolution of the diverse insect lineages is one of the most fascinating issues in evolutionary biology. Despite extensive research in this area, the resolution of insect phylogeny especially of interordinal relationships has turned out to be still a great challenge. One of the challenges for insect systematics is the radiation of the polyneopteran lineages with several contradictory and/or unresolved relationships. Here, we provide the first transcriptomic data for three enigmatic polyneopteran orders (Dermaptera, Plecoptera, and Zoraptera) to clarify one of the most debated issues among higher insect systematics. We applied different approaches to generate 3 data sets comprising 78 species and 1,579 clusters of orthologous genes. Using these three matrices, we explored several key mechanistic problems of phylogenetic reconstruction including missing data, matrix selection, gene and taxa number/choice, and the biological function of the genes. Based on the first phylogenomic approach including these three ambiguous polyneopteran orders, we provide here conclusive support for monophyletic Polyneoptera, contesting the hypothesis of Zoraptera + Paraneoptera and Plecoptera + remaining Neoptera. In addition, we employ various approaches to evaluate data quality and highlight problematic nodes within the Insect Tree that still exist despite our phylogenomic approach. We further show how the support for these nodes or alternative hypotheses might depend on the taxon-and/or gene-sampling. 1295 by guest on May 1, 2016 http://gbe.oxfordjournals.org/ Downloaded from FIG. 5.-RADICAL analysis of nodal support. Shown are the RADICAL curves for each of the five phylogenetic hypotheses (at the top) for the complete P_matrix_g data set and the four functional subgroups based on this data set. The y axis shows the CFI and the x axis the concatenation size (number of genes). Insect Phylogenomics GBE

Evolution, 2001

Evolutionary biologists typically assume that the number of eggs fertilized or developing embryos... more Evolutionary biologists typically assume that the number of eggs fertilized or developing embryos produced is correlated with an individual's fitness. Using microsatellite markers, we document for the first time estimates of realized fitness quantified as the number of offspring surviving to adulthood in an insect under field conditions. In a territorial damselfly whose males defend tree hole oviposition sites, patterns of offspring survivorship could not be anticipated by adults. Fewer than half of the parents contributing eggs to a larval habitat realized any reproductive success from their investment. The best fitness correlate was the span over which eggs in a clutch hatched. Among parents, female fecundity and male fertilization success were poor predictors of realized fitness. Although body size was correlated with female clutch size and male mating success, larger parents did not realize greater fitness than smaller ones. The uncoupling of traditional fitness surrogates from realized fitness provides strong empirical evidence that selection at the larval stage constrains selection on mated adults.

Molecular ecology, 2010

Modern taxonomy requires an analytical approach incorporating all lines of evidence into decision... more Modern taxonomy requires an analytical approach incorporating all lines of evidence into decision-making. Such an approach can enhance both species identification and species discovery. The character-based DNA barcode method provides a molecular data set that can be incorporated into classical taxonomic data such that the discovery of new species can be made in an analytical framework that includes multiple sources of data. We here illustrate such a corroborative framework in a dragonfly model system that permits the discovery of two new, but visually cryptic species. In the African dragonfly genus Trithemis three distinct genetic clusters can be detected which could not be identified by using classical taxonomic characters. In order to test the hypothesis of two new species, DNA-barcodes from different sequence markers (ND1 and COI) were combined with morphological, ecological and biogeographic data sets. Phylogenetic analyses and incorporation of all data sets into a scheme called...

Odonates were the first group of organisms where sperm competition and last male sperm precedence... more Odonates were the first group of organisms where sperm competition and last male sperm precedence have been identified. With the development of 10 microsatellites for the emperor dragonfly Anax imperator, the function and priority patterns of the multiple sperm storage organs of females can be studied and compared between species in natural populations. In addition, two microsatellite loci developed for the sister species Anax parthenope, are also highly polymorphic in A. imperator. For the presented 12 microsatellite loci, the number of alleles per locus ranged from two to 24. Observed heterozygosity ranged from 0.07 to 0.88.

Molecular Ecology Notes, 2007

Odonates (dragonflies and damselflies) are important indicators for monitoring anthropogenic impa... more Odonates (dragonflies and damselflies) are important indicators for monitoring anthropogenic impacts on freshwater ecosystems. We developed a panel of microsatellite loci for the keeled skimmer Orthetrum coerulescens, a libellulid dragonfly inhabiting small streams. By using two different isolation techniques, nine microsatellite loci have been isolated. Screening of 209 individuals resulted in an overall number of 88 alleles, ranging from three to 19 alleles per locus. The observed heterozygosity ranged from 0.37 to 0.83. One locus showed significant deviation from Hardy-Weinberg equilibrium.

Conservation Genetics, 2005

Because of their complex mating behaviour and life cycle (alternating aquatic and terrestrial sta... more Because of their complex mating behaviour and life cycle (alternating aquatic and terrestrial stages) odonates provide important model systems for environmental monitoring, evolutionary ecology, and conservation genetics. Many odonate species are endangered and call for the use of non-invasive molecular studies. In the neotropical damselfly Megaloprepus caerulatus we have identified polymorphic microsatellite loci by means of the randomly amplified microsatellite technique (RAMS;. Using the DNA from each a single leg of three unrelated individuals we screened 63 RAPD primers for small size banding patterns. A total of 95 RAPD profiles was hybridized with digoxigenin labelled di-and trinucleotide repeats (GA n , GT n , CA n and AAT n ) and 36 RAPD fragments harbouring microsatellite motifs were isolated. Cloning and sequencing of positive fragments revealed five polymorphic microsatellite loci. Since Megaloprepus caerulatus is a viable bio-indicator for primary rainforests the microsatellite system can be used to study the effects of forest fragmenation on population viability.

Molecular Phylogenetics and Evolution, 2010

In the last few million years, tropical Africa has experienced pronounced climatic shifts with pr... more In the last few million years, tropical Africa has experienced pronounced climatic shifts with progressive aridification. Such changes must have had a great impact on freshwater biota, such as Odonata. With about forty species, Trithemis dominates dragonfly communities across Africa, from rain-pools to streams, deserts to rainforests, and lowlands to highlands. Red-bodied species tend to favor exposed, standing and often temporary waters, have strong dispersal capacities, and some of the largest geographic ranges in the genus. Those in cooler habitats, like forest streams, are generally dark-bodied and more sedentary. We combined molecular analyses of ND1, 16S, and ITS (ITSI, 5.8S, and ITSII) with morphological, ecological, and geographical data for 81% of known Trithemis species, including three Asian and two Madagascan endemics. Using molecular clock analyses, the genus's origin was estimated 6-9 Mya, with multiple lineages arising suddenly around 4 Mya. Open stagnant habitats were inferred to be ancestral and the rise of Trithemis may have coincided with savannah-expansion in the late Miocene. The adaptation of red species to more ephemeral conditions leads to large ranges and limited radiation within those lineages. By contrast, three clades of dark species radiated in the Plio-Pleistocene, each within distinct ecological confines: (1) lowland streams, (2) highland streams, and (3) swampy habitats on alternating sides of the Congo-Zambezi watershed divide; together giving rise to the majority of species diversity in the genus. During Trithemis evolution, multiple shifts from open to more forested habitats and from standing to running waters occurred. Allopatry by habitat fragmentation may be the dominant force in speciation, but possibly genetic divergence across habitat gradients was also involved. The study demonstrates the importance of combining ecological and phylogenetic data to understand the origin of biological diversity under great environmental change.

Berliner und Münchener tierärztliche Wochenschrift

In zoonosis research only correct assigned host-agent-vector associations can lead to success. If... more In zoonosis research only correct assigned host-agent-vector associations can lead to success. If most biological species on Earth, from agent to host and from procaryotes to vertebrates, are still undetected, the development of a reliable and universal diversity detection tool becomes a conditio sine qua non. In this context, in breathtaking speed, modern molecular-genetic techniques have become acknowledged tools for the classification of life forms at all taxonomic levels. While previous DNA-barcoding techniques were criticised for several reasons (Moritz and Cicero, 2004; Rubinoff et al., 2006a, b; Rubinoff, 2006; Rubinoff and Haines, 2006) a new approach, the so called CAOS-barcoding (Character Attribute Organisation System), avoids most of the weak points. Traditional DNA-barcoding approaches are based on distances, i. e. they use genetic distances and tree construction algorithms for the classification of species or lineages. The definition of limit values is enforced and pro...

BMC Evolutionary Biology, 2009

Background: Whenever different data sets arrive at conflicting phylogenetic hypotheses, only test... more Background: Whenever different data sets arrive at conflicting phylogenetic hypotheses, only testable causal explanations of sources of errors in at least one of the data sets allow us to critically choose among the conflicting hypotheses of relationships. The large (28S) and small (18S) subunit rRNAs are among the most popular markers for studies of deep phylogenies. However, some nodes supported by this data are suspected of being artifacts caused by peculiarities of the evolution of these molecules. Arthropod phylogeny is an especially controversial subject dotted with conflicting hypotheses which are dependent on data set and method of reconstruction. We assume that phylogenetic analyses based on these genes can be improved further i) by enlarging the taxon sample and ii) employing more realistic models of sequence evolution incorporating nonstationary substitution processes and iii) considering covariation and pairing of sites in rRNA-genes.

One of the most widely distributed dragonfly species in Africa is the red-veined-dropwing Trithem... more One of the most widely distributed dragonfly species in Africa is the red-veined-dropwing Trithemis arteriosa. It is an indicator for permanent water bodies, which are freshwater ecosystems of high environmental value especially in arid regions. For studies to determine population structures, assess species viability and monitor environmental changes, a panel of 10 polymorphic microsatellite loci was developed. The number of alleles per locus ranged from four to 12, with an observed heterozygosity ranging from 0.149 to 0.843.

Heredity, 2012

It has been postulated that obligate asexual lineages may persist in the long term if they escape... more It has been postulated that obligate asexual lineages may persist in the long term if they escape from negative interactions with either sexual lineages or biological enemies; and thus, parthenogenetic populations will be more likely to occur in places that are difficult for sexuals to colonize, or those in which biological interactions are rare, such as islands or island-like habitats. Ischnura hastata is the only known example of natural parthenogenesis within the insect order Odonata, and it represents also a typical example of geographic parthenogenesis, as sexual populations are widely distributed in North America, whereas parthenogenetic populations of this species have only been found at the Azores archipelago. In order to gain insight in the origin and distribution of parthenogenetic I. hastata lineages, we have used microsatellites, mitochondrial and nuclear DNA sequence data, to examine the population genetic structure of this species over a wide geographic area. Our resul...

Molecular Phylogenetics and Evolution, 2010

Pterygota are traditionally divided in two lineages, the ''Palaeoptera" and Neoptera. Despite sev... more Pterygota are traditionally divided in two lineages, the ''Palaeoptera" and Neoptera. Despite several efforts neither morphology nor molecular systematics have resolved the phylogeny of the pterygote insects. Too few markers have yet been identified for adequately tracking mesozoic-aged divergences. We tested the Elongation factor-1a for its phylogenetic value in pterygote insect systematics. This highly conserved nuclear protein-coding gene has previously been reported to be useful in other groups for phylogenetic analyses at the intraordinal level as well as at the interordinal level. The analyses suggest that EF-1a DNA sequences as well as intron positions provide informative markers for pterygote phylogenetics.

Molecular Phylogenetics and Evolution, 2013

With respect to bauplan radiation, species and taxa richness, hexapods have an unassailable lead.... more With respect to bauplan radiation, species and taxa richness, hexapods have an unassailable lead. But still, the phylogenetic relationships among the orders and infraorders remain a matter of discussion. The rapidly increasing mitochondrial genome sequences from diverse insect species provide the opportunity to explore miscellaneous evolutionary questions in the superclass Hexapoda. A combined primary sequence analyses of the complete available data set has not yet been performed. Until now phylogenetic analyses of subsets of selected taxa resulted to strong supported topologies showing in some instances discrepancies between morphological and nuclear data. This circumstance started the discussion about the limits of complete mitochondrial genomes for inferring deep hexapod relationships. By using the hitherto densest taxon sampling of Hexapoda our analyses resulted in discrepancies to the current phylogenetic hypotheses based on morphological and nuclear data, e.g. monophyly of hexapods and some hexapods orders, e.g. Diptera, Hemiptera and Orthoptera. Nonetheless, compared to previously published studies that strongly support systematically erroneous groups using a sparse taxon sampling, our analyses had no support for theses discrepancies. Consequently, we highly recommend interpreting mt-genome based phylogenies with incomplete representation of major orders/taxa particularly for hexapods with cautions although the inferred relationships are highly supported.

Molecular Ecology Resources, 2013

The mitochondrial CO1 gene (cytochrome c oxidase I) is a widely accepted metazoan barcode region.... more The mitochondrial CO1 gene (cytochrome c oxidase I) is a widely accepted metazoan barcode region. In insects, the mitochondrial NADH dehydrogenase subunit 1 (ND1) gene region has proved to be another suitable marker especially for the identification of lower level taxonomic entities such as populations and sister species. To evaluate the potential of distance-based thresholds and character-based DNA barcoding for the identification of problematic species-rich taxa, both markers, CO1 and ND1, were used as test parameters in odonates. We sequenced and compared gene fragments of CO1 and ND1 for 271 odonate individuals representing 51 species, 22 genera and eight families. Our data suggests that (i) the combination of the CO1 and ND1 fragment forms a better identifier than a single region alone; and (ii) the character-based approach provides higher resolution than the distance-based method in Odonata especially in closely related taxonomic entities.

Genome Biology and Evolution, 2012

The evolution of the diverse insect lineages is one of the most fascinating issues in evolutionar... more The evolution of the diverse insect lineages is one of the most fascinating issues in evolutionary biology. Despite extensive research in this area, the resolution of insect phylogeny especially of interordinal relationships has turned out to be still a great challenge. One of the challenges for insect systematics is the radiation of the polyneopteran lineages with several contradictory and/or unresolved relationships. Here, we provide the first transcriptomic data for three enigmatic polyneopteran orders (Dermaptera, Plecoptera, and Zoraptera) to clarify one of the most debated issues among higher insect systematics. We applied different approaches to generate 3 data sets comprising 78 species and 1,579 clusters of orthologous genes. Using these three matrices, we explored several key mechanistic problems of phylogenetic reconstruction including missing data, matrix selection, gene and taxa number/choice, and the biological function of the genes. Based on the first phylogenomic approach including these three ambiguous polyneopteran orders, we provide here conclusive support for monophyletic Polyneoptera, contesting the hypothesis of Zoraptera + Paraneoptera and Plecoptera + remaining Neoptera. In addition, we employ various approaches to evaluate data quality and highlight problematic nodes within the Insect Tree that still exist despite our phylogenomic approach. We further show how the support for these nodes or alternative hypotheses might depend on the taxon-and/or gene-sampling. 1295 by guest on May 1, 2016 http://gbe.oxfordjournals.org/ Downloaded from FIG. 5.-RADICAL analysis of nodal support. Shown are the RADICAL curves for each of the five phylogenetic hypotheses (at the top) for the complete P_matrix_g data set and the four functional subgroups based on this data set. The y axis shows the CFI and the x axis the concatenation size (number of genes). Insect Phylogenomics GBE

Evolution, 2001

Evolutionary biologists typically assume that the number of eggs fertilized or developing embryos... more Evolutionary biologists typically assume that the number of eggs fertilized or developing embryos produced is correlated with an individual's fitness. Using microsatellite markers, we document for the first time estimates of realized fitness quantified as the number of offspring surviving to adulthood in an insect under field conditions. In a territorial damselfly whose males defend tree hole oviposition sites, patterns of offspring survivorship could not be anticipated by adults. Fewer than half of the parents contributing eggs to a larval habitat realized any reproductive success from their investment. The best fitness correlate was the span over which eggs in a clutch hatched. Among parents, female fecundity and male fertilization success were poor predictors of realized fitness. Although body size was correlated with female clutch size and male mating success, larger parents did not realize greater fitness than smaller ones. The uncoupling of traditional fitness surrogates from realized fitness provides strong empirical evidence that selection at the larval stage constrains selection on mated adults.

Molecular ecology, 2010

Modern taxonomy requires an analytical approach incorporating all lines of evidence into decision... more Modern taxonomy requires an analytical approach incorporating all lines of evidence into decision-making. Such an approach can enhance both species identification and species discovery. The character-based DNA barcode method provides a molecular data set that can be incorporated into classical taxonomic data such that the discovery of new species can be made in an analytical framework that includes multiple sources of data. We here illustrate such a corroborative framework in a dragonfly model system that permits the discovery of two new, but visually cryptic species. In the African dragonfly genus Trithemis three distinct genetic clusters can be detected which could not be identified by using classical taxonomic characters. In order to test the hypothesis of two new species, DNA-barcodes from different sequence markers (ND1 and COI) were combined with morphological, ecological and biogeographic data sets. Phylogenetic analyses and incorporation of all data sets into a scheme called...

Odonates were the first group of organisms where sperm competition and last male sperm precedence... more Odonates were the first group of organisms where sperm competition and last male sperm precedence have been identified. With the development of 10 microsatellites for the emperor dragonfly Anax imperator, the function and priority patterns of the multiple sperm storage organs of females can be studied and compared between species in natural populations. In addition, two microsatellite loci developed for the sister species Anax parthenope, are also highly polymorphic in A. imperator. For the presented 12 microsatellite loci, the number of alleles per locus ranged from two to 24. Observed heterozygosity ranged from 0.07 to 0.88.

Molecular Ecology Notes, 2007

Odonates (dragonflies and damselflies) are important indicators for monitoring anthropogenic impa... more Odonates (dragonflies and damselflies) are important indicators for monitoring anthropogenic impacts on freshwater ecosystems. We developed a panel of microsatellite loci for the keeled skimmer Orthetrum coerulescens, a libellulid dragonfly inhabiting small streams. By using two different isolation techniques, nine microsatellite loci have been isolated. Screening of 209 individuals resulted in an overall number of 88 alleles, ranging from three to 19 alleles per locus. The observed heterozygosity ranged from 0.37 to 0.83. One locus showed significant deviation from Hardy-Weinberg equilibrium.

Conservation Genetics, 2005

Because of their complex mating behaviour and life cycle (alternating aquatic and terrestrial sta... more Because of their complex mating behaviour and life cycle (alternating aquatic and terrestrial stages) odonates provide important model systems for environmental monitoring, evolutionary ecology, and conservation genetics. Many odonate species are endangered and call for the use of non-invasive molecular studies. In the neotropical damselfly Megaloprepus caerulatus we have identified polymorphic microsatellite loci by means of the randomly amplified microsatellite technique (RAMS;. Using the DNA from each a single leg of three unrelated individuals we screened 63 RAPD primers for small size banding patterns. A total of 95 RAPD profiles was hybridized with digoxigenin labelled di-and trinucleotide repeats (GA n , GT n , CA n and AAT n ) and 36 RAPD fragments harbouring microsatellite motifs were isolated. Cloning and sequencing of positive fragments revealed five polymorphic microsatellite loci. Since Megaloprepus caerulatus is a viable bio-indicator for primary rainforests the microsatellite system can be used to study the effects of forest fragmenation on population viability.

Molecular Phylogenetics and Evolution, 2010

In the last few million years, tropical Africa has experienced pronounced climatic shifts with pr... more In the last few million years, tropical Africa has experienced pronounced climatic shifts with progressive aridification. Such changes must have had a great impact on freshwater biota, such as Odonata. With about forty species, Trithemis dominates dragonfly communities across Africa, from rain-pools to streams, deserts to rainforests, and lowlands to highlands. Red-bodied species tend to favor exposed, standing and often temporary waters, have strong dispersal capacities, and some of the largest geographic ranges in the genus. Those in cooler habitats, like forest streams, are generally dark-bodied and more sedentary. We combined molecular analyses of ND1, 16S, and ITS (ITSI, 5.8S, and ITSII) with morphological, ecological, and geographical data for 81% of known Trithemis species, including three Asian and two Madagascan endemics. Using molecular clock analyses, the genus's origin was estimated 6-9 Mya, with multiple lineages arising suddenly around 4 Mya. Open stagnant habitats were inferred to be ancestral and the rise of Trithemis may have coincided with savannah-expansion in the late Miocene. The adaptation of red species to more ephemeral conditions leads to large ranges and limited radiation within those lineages. By contrast, three clades of dark species radiated in the Plio-Pleistocene, each within distinct ecological confines: (1) lowland streams, (2) highland streams, and (3) swampy habitats on alternating sides of the Congo-Zambezi watershed divide; together giving rise to the majority of species diversity in the genus. During Trithemis evolution, multiple shifts from open to more forested habitats and from standing to running waters occurred. Allopatry by habitat fragmentation may be the dominant force in speciation, but possibly genetic divergence across habitat gradients was also involved. The study demonstrates the importance of combining ecological and phylogenetic data to understand the origin of biological diversity under great environmental change.