A high-resolution transcriptome map of the sea urchin embryo

The sea urchin S. purpuratus is a model organism for study of the genomic control circuitry underlying embryonic development. We examined the complete repertoire of genes expressed in the S. purpuratus embryo, up to late gastrula stage, by means of high-resolution custom tiling arrays covering the whole genome. We detected complete spliced structures even for genes known to be expressed at low leveles in only a few cells. At least 11,000 to 12,000 genes are used in embryogenesis. These include most of the genes encoding transcription factors and signaling proteins, as well as some classes of general cytoskeletal and metabolic proteins, but only a minor fraction of genes encoding immune functions and sensory receptors. Thousands of small asymmetric transcripts of unknown function were also detected in intergenic regions throughout the genome. The tiling array data were used to correct and authenticate several thousand gene models during the genome annotation process. Keywords: high-resolution tiling array, sea urchin, embryo Keywords: other Poly-A RNA from egg, early blastula (15hr.), early gastrula (30hr.) and late gastrula stage (45hr.) embryos of sea urchin were mixed in equal quantities. The RNA sample was converted to cDNA and fluorescently labeled. Single hybridization experiment was performed.