Publications by authors named "Heike Hadrys"

As the longest-winged odonate species of the extant world, Megaloprepus caerulatus (Drury, 1782) has received attention by many entomologists. While the behavior and ecology of this species has been subject of intense studies, biogeography and species status throughout its distributional range in old-growth Neotropical forests are less well known. For tropical forests, this information is a sine qua non when estimating the impact of degradation and climate change.

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Placozoans are a promising model system to study fundamental regeneration processes in a morphologically and genetically very simple animal. We here provide a brief introduction to the enigmatic Placozoa and summarize the state of the art of animal handling and experimental manipulation possibilities.

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The placozoan Trichoplax adhaerens has been bridging gaps between research disciplines like no other animal. As outlined in part 1, placozoans have been subject of hot evolutionary debates and placozoans have challenged some fundamental evolutionary concepts. Here in part 2 we discuss the exceptional genetics of the phylum Placozoa and point out some challenging model system applications for the best known species, Trichoplax adhaerens.

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Article Synopsis
  • Trichoplax adhaerens is a simple, primitive organism with no symmetry or complex structures, making it a candidate for studying ancestral metazoan traits.
  • Its genome is the smallest among metazoans but contains a diverse range of genes, suggesting it could represent early evolutionary developments.
  • The study of Trichoplax may provide insights into the essential features of animal organization and the potential issues that arise when these are not present.
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is the world's most abundant and widely distributed dragonfly and with its outstanding migratory capacity an important model system to study insect migration at the evolutionary base of winged insects. We here report on the first complete mitochondrial genome (mitogenome) of sampled from a population in Rufiji River, Tanzania. The mitogenome is 14,853 bp long with an AT-biased base composition (72.

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The evolution, development and coloration of insect wings remains a puzzling subject in evolutionary research. In basal flying insects such as Odonata, genomic research regarding bauplan evolution is still rare. Here we focus on the world's largest odonate species-the "forest giant" Megaloprepus caerulatus, to explore its potential for looking deeper into the development and evolution of wings.

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Identifying transcriptional changes during embryogenesis is of crucial importance for unravelling evolutionary, molecular and cellular mechanisms that underpin patterning and morphogenesis. However, comparative studies focusing on early/embryonic stages during insect development are limited to a few taxa. Drosophila melanogaster is the paradigm for insect development, whereas comparative transcriptomic studies of embryonic stages of hemimetabolous insects are completely lacking.

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Modern conservationists call for long term genetic monitoring datasets to evaluate and understand the impact of human activities on natural ecosystems and species on a global but also local scale. However, long-term monitoring datasets are still rare but in high demand to correctly identify, evaluate and respond to environmental changes. In the presented study, a population of the riverine dragonfly, Orthetrum coerulescens (Odonata: Libellulidae), was monitored over a time period from 1989 to 2013.

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Article Synopsis
  • The effectiveness of DNA barcoding for identifying and classifying species is heavily influenced by the choice of genetic markers used, particularly for dragonflies and damselflies.
  • A new region of the CO1 gene, referred to as CO1B, is explored alongside the traditional Folmer region and the ND1 gene, showing different performance levels in terms of sequence generation speed, reproducibility, and ability to distinguish closely related species.
  • CO1B shows promising results, particularly in distinguishing sister taxa, while the Folmer region faced challenges, suggesting that CO1B could significantly improve species-level identification in future biomonitoring efforts.
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The increase in atmospheric carbon dioxide (CO) leads to rising temperatures and acidification in the oceans, which directly or indirectly affects all marine organisms, from bacteria to animals. We here ask whether the simplest-and possibly also the oldest-metazoan animals, the placozoans, are particularly sensitive to ocean warming and acidification. Placozoans are found in all warm and temperate oceans and are soft-bodied, microscopic invertebrates lacking any calcified structures, organs, or symmetry.

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The double-stranded, circular mitochondrial DNA (mtDNA), which is present in all eukaryotic life forms, was initially discovered and characterized in the last century and has been widely used in evolutionary studies. Since then, a large number of studies have taken advantage of the genetic information encoded in this genome. Because of its small size in animals (in general), the technical ease of manipulating mitochondrial genome and the dynamics of its evolutionary change, this genome has been the workhorse of evolutionary studies over the past three decades.

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Here we report the complete mitochondrial genome of the emperor dragonfly, (Odonata: Aeshnidae) as the first of its genus. Data were generated via next generation sequencing (NGS) and assembled using an iterative approach. The typical metazoan set of 37 genes (13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes) was detected in the same gene order as in other odonate mitogenomes.

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Damselflies of the genus emerge as organisms with high potential in ecological, evolutionary and developmental research at the base of flying insects. and are for example one of the few odonate species where a complete life cycle over generations can be reared under laboratory conditions. We here report the complete mitochondrial genome of as a valuable genomic resource for future eco-evo-devo studies at the base of flying insects.

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Odonata (dragonflies and damselflies) is a small order at the base of flying insects (Pterygota). Resolving family-level phylogenetic relationships within this order receives great attention. Hereby, genetic data already resulted in various changes, which are however still under discussion.

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DNA barcoding has emerged as a routine tool in modern taxonomy. Although straightforward, this approach faces new challenges, when applied to difficult situation such as defining cryptic biodiversity. Ants are prime examples for high degrees of cryptic biodiversity due to complex population differentiation, hybridization and speciation processes.

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About 2800 mitochondrial genomes of Metazoa are present in NCBI RefSeq today, two thirds belonging to vertebrates. Metazoan phylogeny was recently challenged by large scale EST approaches (phylogenomics), stabilizing classical nodes while simultaneously supporting new sister group hypotheses. The use of mitochondrial data in deep phylogeny analyses was often criticized because of high substitution rates on nucleotides, large differences in amino acid substitution rate between taxa, and biases in nucleotide frequencies.

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Article Synopsis
  • Hexapods, including insects, show a significant variety in species and taxa richness, but their evolutionary relationships remain debated due to differing results from morphological and genetic data.
  • The rise in mitochondrial genome sequences allows for new evolutionary insights, but comprehensive analyses combining all available data have not been done yet.
  • Recent studies using dense taxon sampling reveal contradictions to existing phylogenetic theories, suggesting the need for careful interpretation of mitochondrial genome-based phylogenies, especially when major groups are underrepresented.
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Article Synopsis
  • The study addresses the complexities in insect relationships, particularly the polyneopteran lineages, which have presented unresolved phylogenetic challenges in evolutionary biology.
  • Researchers presented new transcriptomic data for three polyneopteran orders (Dermaptera, Plecoptera, and Zoraptera) to clarify their evolutionary relationships and tested various methodologies for phylogenetic analysis.
  • The findings support the idea of monophyletic Polyneoptera, contradicting previous hypotheses, while also identifying ongoing issues in data quality and the impact of taxon and gene sampling on the phylogenetic tree.
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Among gene families it is the Hox genes and among metazoan animals it is the insects (Hexapoda) that have attracted particular attention for studying the evolution of development. Surprisingly though, no Hox genes have been isolated from 26 out of 35 insect orders yet, and the existing sequences derive mainly from only two orders (61% from Hymenoptera and 22% from Diptera). We have designed insect specific primers and isolated 37 new partial homeobox sequences of Hox cluster genes (lab, pb, Hox3, ftz, Antp, Scr, abd-a, Abd-B, Dfd, and Ubx) from six insect orders, which are crucial to insect phylogenetics.

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Molecular sequences do not only allow the reconstruction of phylogenetic relationships among species, but also provide information on the approximate divergence times. Whereas the fossil record dates the origin of most multicellular animal phyla during the Cambrian explosion less than 540 million years ago(mya), molecular clock calculations usually suggest much older dates. Here we used a large multiple sequence alignment derived from Expressed Sequence Tags and genomes comprising 129genes (37,476 amino acid positions) and 117 taxa, including 101 arthropods.

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Unraveling animal life cycles and embryonic development is basic to understanding animal biology and often sheds light on phylogenetic relationships. A key group for understanding the evolution of the Metazoa is the early branching phylum Placozoa, which has attracted rapidly increasing attention. Despite over a hundred years of placozoan research the life cycle of this enigmatic phylum remains unknown.

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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.

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Arthropods were the first animals to conquer land and air. They encompass more than three quarters of all described living species. This extraordinary evolutionary success is based on an astoundingly wide array of highly adaptive body organizations.

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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.

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