An automatable method for high throughput analysis of evolutionary patterns in slightly complex indels and its application to the deep phylogeny of Metazoa

• Insertions/deletions (indels) in protein sequences are potential powerful evolutionary markers. However, these characters have rarely been explored systematically at deep phylogenetic levels. Previous analyses of simple (2-state) clade defining indels (CDIs) in universal eukaryotic proteins found none to support any major animal clade. We hypothesized that CDIs might still be found in the remaining population of indels, which we term complex indels. Here, we propose a method for analyzing the simplest class of complex indels the “slightly complex indels”, and use these to investigate deep branches in animal phylogeny. Complex indels with two states, called bi-state indels, show similar evolutionary patterns to singleton simple indels and confirms that insertion mutations are more common than deletions. Exploration of CDIs in 2- to 9-state complex indels shows strong support for all examined branches of fungi and Archaeplastida. Surprisingly, we also found CDIs supporting major branches in animals, particular in vertebrates. We then expanded the search to non-bilaterial animals (Porifera, Cnidaria and Ctenophora). The phylogenetic tree reconstructed by CDIs places the Ctenophore Mnemiopsis leidyi as the deepest branch of animals with 6 CDIs support. Trichoplax adhaerens is closely related to the Bilateria. Moreover, the indel phylogeny shows Nematostella vectensis and Hydra magnipapillata are paraphyletic group and position of Cnidarian branches seems to be problematic in the indel phylogeny because of homoplasy. This might be solved if we discover CDIs from animal specific proteins, which emerged after the universal orthologous proteins.Evolutionary Patterns in Slightly Complex Protein Insertions/Deletions (Indels) and Their Application to the Study of Deep Phylogeny in Metazoa

Subject headings

NATURVETENSKAP  -- Biologi -- Annan biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Other Biological Topics (hsv//eng)

Publication and Content Type

vet (subject category)

ovr (subject category)