Periodic Reporting for period 2 - TETHYS (The evolution and regulation of major transitions in sexual systems: new insights from the brown algae)
Reporting period: 2022-07-01 to 2023-12-31
2. By exploiting inbred pedigrees of the brown algae Ectocarpus and Scytosiphon, we accessed for the first time to the spontaneous mutation rate of representative organisms of a complex multicellular eukaryotic lineage outside animals and plants, and revealed the impact of life cycle on mutation rate. Krasovec et al MBE 2023
3. We explored isogenic male and female lines of the model brown alga Ectocarpus and employed sex-specific transcriptomic and ChIP-seq datasets to disclose the chromatin dynamics underlying sexual differentiation. Our findings offered new, comparative insights into the interactions between chromatin configurations and gene expression patterns in males versus females, with wide implications to animal and plant systems. Gueno et al. 2022
4. We provide the first illustration of how male- and female-specific developmental programs in a haploid sex determination system may be uncoupled from sex chromosome identity. We reveal new and key aspects of the evolution of sex-specific and sex-biased gene expression patterns in the third most complex multicellular eukaryotic lineage3, increasing our knowledge on evolution of sexual dimorphism in the context of the Tree of Life. (Muller et al New Phyt 2022)
5. We have produced an Atlas of gene expression for 22 species across the phylogeny of the brown algae, and covering 6-15 stages of development during their life cycle. This Seaweed Expression Atlas is being used to understand the emergence and evolution of multicellular development and sexual differentiation. We are building a database that will be an open resource for the scientific community.