Abstract:  Whole-genome sequencing of the local sponge Amphimedon queenslandica (class Demospongia) demonstrated that sponges have a limited repertoire of developmental transcription factors subfamilies in comparison to cnidarians and bilaterians. This is in line with the view that increased morphological complexity in the animal lineage correlate with developmental toolkit complexity. However, the phylum Porifera is represented by a wide variety of species with different larval and adult morphologies, and thus it was unclear whether the genome of Amphimedon represented all sponges. In this seminar, I will show you how we combined genomic, transcriptomic and in situ hybridization approaches to reconstruct a comprehensive evolutionary history of transcription factors and understand mechanisms of development using another sponge, Sycon ciliatum (representing the Calcarea). Our analyses reveal that in many cases the calcisponge developmental toolkit of transcription factors differs significantly from the one in Amphimedon. The differences between the two sponge lineages appear to be driven by a combination of independent gene loss and gene family expansions. Additionally, we used our data to identify sensory cells and investigate mechanisms of regeneration in Sycon. Results of our studies highlight the importance of sequencing the genomes of multiple sponge species and using transcriptomic data to obtain a more complete understanding of sponge development and the early evolution of animal developmental genes.

Biography:  Sofia is originally from Caracas (Venezuela) where she obtained a Licenciatura in Biology (2004). During this period she participated in projects for monitoring coral, reef health and environmental microbiology. In her Honors thesis, she characterized the bacterial communities associated with the coral Montastraea faveolata affected with yellow band disease. She then moved to Bergen, Norway, and undertook a Master in marine microbiology (2006-2008), where she characterized the bacterial communities associated with the sponge Geodia barretti using molecular tools. In 2008 she started as a PhD candidate in evolutionary developmental biology at the Adamska’s group (Sars Centre of Marine Molecular Biology, Bergen, Norway), during which the group undertook the genome project for the calcareous sponge, Sycon ciliatum. Using a combination of transcriptomics, genomics and in situ hybridization, she studied the evolution of developmental transcription factors in early animals and traced sensory mechanism in calcareous sponges. She continues as a Postdoctoral Research fellow in the same group and currently works on the genome projects for three other calcareous sponges. Her future interest is to integrate ecology, molecular genetics tools and developmental biology approaches to study the effect of environmental stressors on the life cycles, and the mechanisms of regeneration, in marine invertebrates.