The Global Invertebrate Genomics Alliance (GIGA): Developing Community Resources to Study Diverse Invertebrate Genomes

Selection of Taxa Porifera (sponges) are a diverse taxon of benthic aquatic (marine and limnic) animals, with over 8,500 described species distributed over four main extant lineages: Demospongiae (83% of living species; demosponges, including bath sponges), Hexactinellida (glass sponges), Calcarea (calcareous sponges), and Homoscleromorpha (flesh sponges) (Van Soest et al. 2012) (Fig. 2). Traditionally, sponges were considered the sister group to the rest of Metazoa, and therefore of great significance for the reconstruction of early metazoan evolution. Sponges are now regarded to be monophyletic (reviewed in Wörheide et al. 2012), though further work is needed to unequivocally resolve their placement among the other non-bilaterian animals (i.e., those without bilateral symmetry) (Fig. 1). Although sponges are of great importance ecologically (as filter-feeders, bioeroders, and habitat formers), commercially (e.g., bath sponges) and pharmaceutically (as producers of bioactive secondary metabolites), their internal phylogeny and genomic diversity remains unresolved and understudied (Lavrov et al, 2008; Wörheide et al., 2012; Hill et al 2013). Comparative genomic approaches will not only shed light on the early evolution of metazoan genomes, but also unravel the genomic adaptations that led to the enormous ecological success of sponges over 550 million years. Comparative genomics will advance our understanding of the processes responsible for secondary metabolite production as well as unravel the genetic basis for biosilica synthesis, both of which have enormous potential for biomedical and biomimetic applications. Currently, the genome of only one sponge (Amphimedon queenslandica) has been published (Srivastava et al. 2010), a species not easily amenable to laboratory culture and experimental manipulation.