The project adopted an interdisciplinary approach through combining experimental evolution with phylogenomics. More specifically, populations of unicellular cyanobacteria have been subjected to long-term experimental evolution under different regimes that favour either the specialization of cells into performing different physiologically incompatible processes within a multicellular group, or the formation of non-differentiated aggregates. While only the focal selection regime has resulted in the formation of multicellular groups, the underlying genotype and gene expression patterns will still need to be determined. The ultimate goal is it to establish the critical steps for the transition to multicellularity at the genome level.
The bioinformatics part of the project provides the first account ever that reconstruct a concrete evolutionary scenario for a transition to multicellularity that happened in cyanobacteria in the earliest epochs of life’s history. Our results show that the prime driver of multicellularity in cyanobacteria was the capability of nitrogen fixation, which was accompanied by the emergence of the filamentous morphology and a reproductive life cycle. This was followed by a range of niche expansions and interactions with other species, and the progression of multicellularity into higher complexity in the form of differentiated cells and patterned multicellularity.
Results from the bioinformatics part of the project have been summarized for publication, which is currently available as a preprint (Hammerschmidt et al 2019, bioRxiv 570788). They have also been disseminated at seminars, workshops, and conferences (total of 14), and communicated to the public (four talks and one poster).
