Four myriapod relatives – but who are sisters? No end to debates on relationships among the four major myriapod subgroups

BackgroundPhylogenetic relationships among the myriapod subgroups Chilopoda, Diplopoda, Symphyla and Pauropoda are still not robustly resolved. The first phylogenomic study covering all subgroups resolved phylogenetic relationships congruently to morphological evidence but is in conflict with most previously published phylogenetic trees based on diverse molecular data. Outgroup choice and long-branch attraction effects were stated as possible explanations for these incongruencies. In this study, we addressed these issues by extending the myriapod and outgroup taxon sampling using transcriptome data.ResultsWe generated new transcriptome data of 42 panarthropod species, including all four myriapod subgroups and additional outgroup taxa. Our taxon sampling was complemented by published transcriptome and genome data resulting in a supermatrix covering 59 species. We compiled two data sets, the first with a full coverage of genes per species (292 single-copy protein-coding genes), the second with a less stringent coverage (988 genes). We inferred phylogenetic relationships among myriapods using different data types, tree inference, and quartet computation approaches. Our results unambiguously support monophyletic Mandibulata and Myriapoda. Our analyses clearly showed that there is strong signal for a single unrooted topology, but a sensitivity of the position of the internal root on the choice of outgroups. However, we observe strong evidence for a clade Pauropoda+Symphyla, as well as for a clade Chilopoda+Diplopoda.ConclusionsOur best quartet topology is incongruent with current morphological phylogenies which were supported in another phylogenomic study. AU tests and quartet mapping reject the quartet topology congruent to trees inferred with morphological characters. Moreover, quartet mapping shows that confounding signal present in the data set is sufficient to explain the weak signal for the quartet topology derived from morphological characters. Although outgroup choice affects results, our study could narrow possible trees to derivatives of a single quartet topology. For highly disputed relationships, we propose to apply a series of tests (AU and quartet mapping), since results of such tests allow to narrow down possible relationships and to rule out confounding signal

The prognostic impact of pulmonary metastasectomy in recurrent gynecologic cancers: a retrospective single-institution study

The aim was to examine the impact of pulmonary metastasectomy in patients with recurrent gynecologic cancers. Thirty-seven patients with isolated lung metastases (2 years) was significantly favorable (5-year OS 100% vs. 41.7%, p=0.006). Among the 6 patients with re-recurrence of lung metastases, 5 patients underwent a second pulmonary metastasectomy, and all of the patients are currently alive without disease. None of the 29 operations yielded severe complications. Although the survival rate showed a tendency to be higher in the surgery group than in the chemotherapy-only group, no significant difference was observed (5-year OS 81.7% vs. 49.5%, p=0.072). Our results indicate that pulmonary metastasectomy contributed to long-term survival with a low-risk of complications. Surgery to remove isolated lung metastases might provide a favorable prognosis for patients with long recurrence-free intervals and for patients with chemoresistant or re-recurrent tumors

The homology of cephalic muscles and endoskeletal elements between Diplura and Ectognatha (Insecta)

Diplura (two-pronged bristletails) are key to our understanding of hexapod head evolution. A sister group relationship with Ectognatha (=Insecta), comprising bristletails, silverfish and winged insects, is advocated in most modern studies, however, homologization of head muscles and endoskeletal elements between Diplura and Ectognatha is still lacking. Here, we present the first homologization of a number of head muscles and endoskeletal structures between Diplura and Ectognatha. A homologization of these structures is possible if a range of species, both from Japygidae and Campodeidae, are studied in order to reconstruct the potential groundplan characteristics and account for inner anatomy variations within Diplura. Japygidae and Campodeidae show differences in the origin, insertion, and presence of mandibular and maxillary muscles as well as the shape of the maxillary cardo. Taking into account recent embryological studies on the formation of the endoskeleton in Protura, Collembola and Diplura, we furthermore reconstruct the potential evolution of the endoskeleton in early Hexapoda. The tentorium is a defining feature of dicondylic insects (including Archaeognatha) while anterior and posterior cephalic invaginations (the later tentorial pits of dicondylic insects) are groundplan features of Hexapoda. Additionally, we clarify the composition of the gnathal pouches (i.e. the type of entognathy) in Diplura and Collembola. The pouches in Diplura are posteriorly separated, similar to the state encountered in Collembola. This contrasts to former studies emphasizing the differences in the ellipuran and dipluran type of entognathy

Data from: Phylogenomics resolves the timing and pattern of insect evolution

Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relations hips. We dated the origin of insects to the Early Ordovician [~479 million years ago (Ma)], of insect flight to the Early Devonian (~406 Ma), of major extant lineages to the Mississippian (~345 Ma), and the major diversification of holometabolous insects to the Early Cretaceous. Our phylogenomic study provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects

Data from: Phylogenomics resolves the timing and pattern of insect evolution

Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relations hips. We dated the origin of insects to the Early Ordovician [~479 million years ago (Ma)], of insect flight to the Early Devonian (~406 Ma), of major extant lineages to the Mississippian (~345 Ma), and the major diversification of holometabolous insects to the Early Cretaceous. Our phylogenomic study provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects

Phylogenomics Resolves The Timing And Pattern Of Insect Evolution: Supplementary File Archives.

Phylogenomics Resolves The Timing And Pattern Of Insect Evolution: Supplementary File Archives. This file includes 14 supplementary archives which are in detail described in the README