Tissue-specific gene expression analysis of silkworm (Bombyxmori) by quantitative real-time RT-PCR

The Bombyx mori Microarray Database (BmMDB; http://silkworm.swu.edu.cn/microarray) provides information for tissue-specific gene expression by using the whole-genome oligonucleotide microarray in the silkworm. We analyzed the tissue-specific expression patterns in the silk gland, fat body, and midgut five days of fifth instar larvae during the development of B. mori. To verify the tissue-specific expression, analysis was conducted using quantitative Real-time RT-PCR and the highly expressed endogenous Actin RNA as an intrinsic reference. Finally, we confirmed five genes, (sw15872, sw00692, sw20990, sw05300,and sw2250), out of 18 candidates expressed in two different tissues, which was consistent with the data published by Dr. Xiang's group, thereby supporting the BmMDB. Further studies for promoter regions of candidate genes can be applied in creating transgenic silkworms as biomedical insects for use in producing biomaterials, and to serve as well-characterized models for understanding the mechanism for the genetic regulation of tissue-specific development.