High fusibility and chimera prevalence in an invasive colonial ascidian

The formation of chimeric entities through colony fusion has been hypothesized to favour colonisation success and resilience in modular organisms. In particular, it can play an important role in promoting the invasiveness of introduced species. We studied prevalence of chimerism and performed fusion...

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Detalles Bibliográficos
Autores: Casso, M., Tagliapietra, D., Turon Barrera, Xavier, Pascual, M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/151391
Acceso en línea:https://hdl.handle.net/2445/151391
Access Level:acceso abierto
Palabra clave:Urocordats
Colònies animals
Sea squirts
Animal colonies
Descripción
Sumario:The formation of chimeric entities through colony fusion has been hypothesized to favour colonisation success and resilience in modular organisms. In particular, it can play an important role in promoting the invasiveness of introduced species. We studied prevalence of chimerism and performed fusion experiments in Mediterranean populations of the worldwide invasive colonial ascidian Didemnum vexillum. We analysed single zooids by whole genome amplification and genotyping-by-sequencing and obtained genotypic information for more than 2,000 loci per individual. In the prevalence study, we analysed nine colonies and identified that 44% of them were chimeric, composed of 2-3 different genotypes. In the fusion experiment 15 intra- and 30 intercolony pairs were assayed but one or both fragments regressed and died in ~45% of the pairs. Among those that survived for the length of the experiment (30 d), 100% isogeneic and 31% allogeneic pairs fused. Fusion was unlinked to global genetic relatedness since the genetic distance between fused or non-fused intercolony pairs did not differ significantly. We could not detect any locus directly involved in allorecognition, but we cannot preclude the existence of a histocompatibility mechanism. We conclude that chimerism occurs frequently in D. vexillum and may be an important factor to enhance genetic diversity and promote its successful expansion.