Reference transcriptome data in silkwormBombyx mori

Background The silkworm Bombyx mori is a lepidopteran model insect with biological and industrial importance. Its high-quality genome sequence has recently become available and the utilization of this information in combination with extensive transcriptomic analyses is expected to provide an elaborate gene model. It will also be possible to clarify gene expression in detail using this approach. Results We herein performed RNA-seq analysis of ten major tissues/subparts of silkworm larvae. Sequences were mapped onto the reference genome assembly and reference transcriptome data was successfully constructed. The reference data provided a nearly complete sequence for sericin - 1 , a major silk gene with a complex structure. We also markedly improved the gene model for other genes. Transcriptomic expression was investigated in each tissue and a number of transcripts were identified that were exclusively expressed in tissues such as the testis. Transcripts strongly expressed in the midgut formed tight genomic clusters, suggesting that they originated from tandem gene duplication. Transcriptional factor genes expressed in specific tissues or the silk gland subparts were also identified. Conclusions We successfully constructed reference transcriptome data in the silkworm and found that a number of transcripts showed unique expression profiles. These results will facilitate basic studies on the silkworm and accelerate its applications, which will contribute to further advances in lepidopteran and entomological research and the practical use of these insects.