Studying hybrid speciation and introgression using a natural fungal model system

Descripción del proyecto

Éxito y fracaso de los híbridos fúngicos

«Trichaptum abietinum» es una especie de hongo xilófago que forma híbridos cuando sus diferentes poblaciones se solapan. Aunque prospera en Europa central, no ha logrado establecerse en Noruega. Ello plantea una pregunta básica en biología evolutiva: ¿qué ocurre cuando especies o poblaciones divergentes se cruzan? La hibridación puede generar descendencia poco apta o estéril, pero en ocasiones da lugar a individuos con rasgos nuevos que aumentan su supervivencia. Dado que se espera que la hibridación aumente por el cambio climático y la actividad humana, el proyecto FINESSE investiga su papel en la adaptación y la especiación. En FINESSE, que cuenta con el apoyo de las acciones Marie Skłodowska-Curie, se secuenciarán poblaciones silvestres de «T. abietinum», se crearán híbridos en el laboratorio y se utilizará CRISPR-Cas9 para identificar los factores genéticos que explican el éxito y el fracaso de los híbridos.

Objetivo

Hybridisation, mating between distinct species or divergent populations, can lead to a variety of different outcomes. Many hybrid offspring will have low fitness or be inviable, while others may increase fitness under extreme conditions by producing transgressive hybrids with phenotypes outside of their parental range. The role of hybridisation in adaptation and speciation is a key question in evolutionary biology, especially as hybridisation is predicted to rise due to climate change and other human activities.
In FINESSE (Fungal INtrogrESsion and SpEciation) we aim to use the wood-decaying fungus Trichaptum abietinum as a study system for researching hybridisation. In Europe, there are three distinct populations of T. abietinum: a Mediterranean population, a Boreal, and an Atlantic population. Where populations overlap, there are different hybrid outcomes with hybrids found in central Europe but not Norway. These contrasting outcomes make our system ideal to study patterns of introgression and hybridisation in Europe.
During FINESSE we plan to 1) gather and sequence field samples from underrepresented regions across Europe, both to explore the diversity of these populations in Eastern Europe and identify the origin of the Atlantic population in Norway. 2) Generate hybrids in the lab to help us understand the differing hybrid outcomes found in Europe, and identify mechanisms of hybrid incompatibility through genomic and phenotypic assays. 3) Use a reverse genetics approach to identify genes associated with hybrid incompatibilities, using CRISPR-Cas9 transformation of candidate genes. I will also use the project to improve both my scientific and transferable skills by taking courses, from other researchers in the department, during management of the project, and more generally from working on the project. Overall, this project will let me gain the skills necessary to become a more independent researcher and improve my future career prospects.