Algal evolutionary genome dynamics and new insights in coral holobiont structure | - CCMAR -

Algal evolutionary genome dynamics and new insights in coral holobiont structure

Wednesday, May 10, 2023
Anfiteatro D l Complexo Pedagógico l University of Algarve

My seminar will summarise the main findings of some recent work in my team, spanning the fields of algal evolutionary biology and coral holobiont functioning. I will start off with two studies on genome evolution in algae. Starting from the near-neutral theory of molecular evolution, we define a set of hypotheses describing our expectations of the relationship between genome-wide molecular evolutionary dynamics, morphological complexity and life cycle types. Using an unprecedented set of brown algal nuclear genomes, we infer a very strongly supported phylogeny and test our hypotheses on molecular evolution. We demonstrate clear differences in observed drift across life cycle types and levels of morphological complexity, largely in line with the theoretical observations. We show that the dN/dS ratio provides an incomplete picture of the underlying evolutionary dynamics. In the second study, we turn to the highly unusual chloroplast genomes of Cladophorales (Ulvophyceae), which are fragmented into single stranded chromosomes that fold into hairpin structures.

Our latest work shows the sequence of events leading away from conventional chloroplast architecture to these highly reduced linear molecules. By characterising the genomes of strategically selected taxa, we reveal a clear sequence of evolutionary steps, starting with genome reduction, fragmentation and finally a shift from double-stranded molecules to single-stranded hairpins. My group's work on coral biology has focused on the structure and function of the rich microbiota living in the coral skeleton. I will introduce this intriguing system and its eclectic range of photobionts. Using 2D chemical imaging, we characterised the oxygen and pH gradients present in the skeleton, and through micro-sampling, metagenomics and metatranscriptomics, we inferred the link between the microbiome and its spatially structured environment. We are currently working towards bringing these various pieces of information together into an overall model of microbiome structure and function, and are taking steps towards understanding how processes playing out in the skeleton affect how corals fare during bleaching events.


The seminar will be held on May 10, at 13:30, at the Anfiteatro D l Complexo Pedagógico l University of Algarve.
Participation is free but mandatory to register.




About our speaker:
Heroen Verbruggen is an Associate Professor (Marine Botany) in the School of BioSciences, University of Melbourne. His studies include: PhD in Sciences, Biology (Ghent University), Licentiate in de Biologie (Katholiek Universiteit Leuven), and Candidate in de Biologie (Katholiek Universiteit Leuven).



This seminar was kindly sponsored by

Type of Event