Phylogenomic analysis of Nereididae (Annelida)

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Nereididae are a group of annelid worms that can be found worldwide in marine, brackish, or freshwater habitats and more than 650 species have been described. Nereidid annelids have been extensively studied in evolutionary developmental biology, reproductive biology and ecology. The nereidid Platynereis dumerilii became the best investigated model organism of Lophotrochozoa in general. Many important laboratory techniques have been established for this species and gene expression involved in embryogenesis, segment formation and regeneration, development of the nervous system and eyes are studied in detail. Even though nereidids are one of the best investigated annelid taxa, the phylogeny of this group has not been well-resolved so far. However, knowing the phylogenetic relationships of Platynereis dumerilii to its closest relatives is necessary for studying the steps that underlie life history, genomic, and morphological evolution of this important model.The main objective of this project is to reconstruct a well-supported phylogeny for nereidids. By using hybrid target enrichment with subsequent Illumina sequencing, a phylogenomic analysis based on approximately 250 loci derived for around 65 species and 96 individuals (covering different geographic origins for selected species) representing the diversity of nereidids will be conducted. Baits for target enrichment will be based on a set of transcriptomes from 10 selected nereidid species generated within this project. This phylogeny will be used to test if the current classification of nereidids coincides with monophyletic groups. Moreover, this phylogenetic framework will finally provide a stable placement of the model annelid Platynereis dumerilii within nereidids. Based on this phylogeny, ancestral state reconstruction will be used to infer the evolution of reproductive modes, life-style and habitat preference of nereidid worms.