TERRESTREVOL · Exploring terra incognita: terrestrialization of arthropods in the era of genomics
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2018-01-15 → 2020-05-19
- EU contribution
- €170,122
- Participants
- 2
- Scheme
- MSCA-IF
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Results in brief
Exploring terra incognita: terrestrialization of arthropods in the era of genomics
All animals come from the sea, and many of them managed to conquer terrestrial environments. The most successful of these lineages are arthropods, including insects, spiders or myriapods. The goal of this project was to understand how arthropods adapted to life on land. However, a series of questions needed to be addressed beforehand. For instance, arthropod phylogeny has been controversial, particularly in some of the lineages. How do different analyses affect the inferred phylogeny, particularly orthology inference? A second important question revolved around understanding how and when genes arose in this lineage. Are most genes ancient? Did they arise recently? And did they evolve through speciation or duplication? I tackled these questions through a bioinformatic spyglass. Arthropods constitute the most successful animal phylum on our planet. By learning how their genomes evolved, we can hope to further our understanding on how to preserve specific lineages, or how to contain pests. For instance, in one of our publications we investigated how selection affected recent duplicated genes in the pea aphid, Acyrthosiphon pisum, an important pest. We showed that some genes involved in the maintenance of symbiotic relationships with bacteria (key for the aphid since they synthesize some essential amino acids) arose through recent gene duplication, and opens the door to the design of targeted drugs to contain this pest. Overall objectives: (1) How did arthropod genes evolve? Are most genes ‘old’ (i.e., gained in the Animal Tree of Life before arthropods arose) or ‘new’ (i.e., lineage-specific)? Did they evolve through speciation or duplication? (2) How did selection reshaped genes recently duplicated in some arthropod lineages? Conclusions of the action - Most arthropod genes are very ancient and date back to the ancestor of animals and their relatives. - Around one third of the genes in arthropod genomes evolved ‘recently’ (i.e., were gained in the branch leading to the phylum). - Gene duplication was an important force shaping arthropod genomes, potentially facilitating adaptation to life on land. - Genes recently duplicated were also important for pests, as in the case of the pea aphid, where recent duplicates facilitate symbiosis with bacteria.
Data: CORDIS, © European Union
Project objective
Terrestrialization – the colonization of the land habitat by plants and animals – is amongst the most important events in the history of life on Earth. Understanding terrestrialization is, therefore, key to understanding biological adaptation. From all animals, arthropods constitute the most successful phylum, manifest in extreme species richness and successful radiation into nearly every ecological niche. Arthropods colonized the land multiple times independently and at different times in Earth history, with terrestrial arthropods massively outnumbering the aquatic ones. This begs the questions how, when, why and how often did arthropods become successful in the terrestrial environment, constituting ideal model systems to study terrestrial adaptations at the genomic, physiological and morphological levels. In order for animals living in aquatic environments to colonize land, a number of physiological barriers need to be overcome, including massive changes to methods of respiration, water management and osmoregulation, reproduction or digestion, among others. Water balance is one of the main challenges facing primarily terrestrial animals. Osmoregulation is also highly relevant to the question about the route taken onto land, specifically whether the ancestors of a given terrestrial arthropod group came directly from a marine environment or via fresh water. The main goal of this project is to shed light on the mode and tempo of these changes through the integration of phylogenomics, paleontology and comparative genomics and transcriptomics. For this, I propose to investigate i) the genetic basis of cuticular composition in marine and terrestrial arthropod lineages, ii) characterization of genes involved in osmoregulation, and iii) lineage-specific orphan gene families that could have contributed to arthropod evolvability in terrestrialization events. The results of this project will allow an unprecedented understanding of deep-time questions in arthropod evolution.
Original text from CORDIS.
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Data: CORDIS, © European Union