Identify potential maternal genes of Bombyx mori using Digital Gene Expression Profiling

Maternal genes present in mature oocytes and play a crucial role in the early development of the silkworm. Although maternal genes have been widely studied in many species, there are limited research in Bombyx mori. High-through experimental technology provides a practical way for genome-wide study. Here we show a transcriptome study on silkworm eggs. Unfertilized eggs from five different stages of early development were used for detecting the change situation of gene expression. The expressed genes showed different patterns over time. Maternal genes were annotated according to homology analysis with Drosophila melanogaster. In our result, more than a half expressed maternal genes were fall into four expression patterns and showed downward trend over time. The function annotation of material genes showed that they were related to transcription factor activity, growth factor activity, nucleic acid binding, RNA binding, ATP binding, ion binding and so on. In additional, twenty-two gene clusters including material genes were identified from 18 scaffolds. Altogether, we plotted a profile for maternal genes of Bombyx mori using digital gene expression profiling method. It will provide a base for mother-specific signature research and improve the understanding of early development of silkworm. To analyze the differentially expressed genes,in particular the maternal genes,related to embryonic development from 0h to 24h after unfertilized embryos spawning, the silkworm unfertilized embryos are used for RNA-Seq.