title: The holo-transcriptome of a calcified early branching metazoan
design: Sponges are often host to a large and diverse microbial community. We have sequenced the holo-transcriptome of a hypercalcified demosponge and use this resource to characterise some of the molecular components that the sponge host is likely to use to interact with its endobiotic microbial community. A TrueSeq RNA Sample Kit (Illumina, Cat. N°RS-122-2002) was used to generate an mRNA library using 500 ng of total RNA. Sequencing was conducted on the Illumina HiSeq 2000 platform to generate 100 bp paired-end reads.Quality filtering resulted in 34,592,975 paired end reads that were assembled into 91,443 contigs with an average length of 933 bp and an N50 value of 1,307 bp.    The aim of this project was to investigate the complexity of the molecular interactions between the demosponge Vaceletia sp. and its microbial community. Because this sponge is know to harbor an extensive endo-biotic community, and because the growth form of this sponge has clear similarities with organisms dating back to the middle Triassic we are interested in how the sponge and its endobiotic community interacts and how these interactions may have evolved. These interactions may also shed some light on the process of biomineralisation employed by the sponge.