The maternal-to-zygotic transition (MZT) is a major developmental event in both plants and animals. In plants, the timing of MZT and parental contributions to the zygotic transcriptome remain unclear, mostly due to the technical challenge of working with early embryos deeply embedded in the maternal sporophytic tissue in model plants. We are exploiting the amenability of the brown algae embryos (male and female gametes released in seawater, autonomous embryo development, no maternal tissue contamination, synchronous early embryogenesis) to look at parental contributions and interactions between maternal and paternal genomes and the initiation of the embryonic program.
We have access to several Ectocarpus mutants affected in their early development. We are generating further mutants and using classical genetics coupled with transcriptomics, cell biology and biochemical approaches to identify and characterise genes involved in developmental pattern formation and their downstream effectors. Comparative analysis of genes involved in development across eukaryotic supergroups is expected to illuminate the novelties or the conservation of processes involved in the emergence and evolution of multicellularity.