Séminaire externe : Cristian-Cañestro
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Le 04/03/2024, de 11:00 à 12:15 |
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S'adresser à | Yad Ghavi-Helm |
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Séminaire externe : Cristian-Cañestro (Departament de Genètica, Microbiologia i Estadística, Institut de REcerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Catalonia, Spain)
"When LESS is MORE: gene loss and genome scrambling in Oikopleura dioica as an evolutionary knockout model in (Eco)EvoDevo"
Hôte : Yad Ghavi-Helm
Résumé :
Gene losses are pervasive and prevalent over gene gains throughout the tree of life and represent an important source of genetic variation with a great potential to be an adaptive evolutionary force ("the less is more" hypothesis). Work of our group during the last decade has showed that the appendicularian chordate Oikopleura dioica can be used as an attractive evolutionary knockout (eKO) model to study the impact of gene loss in the evolution of mechanisms of development in our own phylum, the chordates. Thus, for instance, we have shown that massive gene losses have led to the deconstruction of the cardiopharyngeal gene regulatory in appendicularians, facilitating the adaptive reacquisition of a free-living style of this group of chordates from an ancestral biphasic sessile ascidian-like tunicate. The recent sequencing and assembly at the chromosome level of the compacted genome of O. dioica specimens around the globe (e.g. Barcelona, Bergen, Osaka, Okinawa) is revealing an unprecedented amount of genome scrambling among populations, which now appear that might be indeed cryptic species, despite they do not present any obvious morphological differences. This finding is now offering a unique system to elucidate if the proneness of O. dioica to lose genes might be connected to its great rate of generation of chromosome breakpoints, to investigate the impact of gene loss on speciation, and to investigate how the remodeling of genome architecture relates with changes of gene regulation.
Lundi 4 mars
Salle Condorcet