ESTs (Expressed Sequence Tags) are 5'- or 3'-end sequences of randomly selected cDNAs. In 2003, 35,000 EST seqeunces from 36 cDNA libraries, were published (1). After that, further analyses have been continuing to expand the EST database. In 2004, the Japanese and Chinese and groups performed whole-genome shotgun analyses (WGS) of the silkworm Bombyx mori in 3x and 6x genome coverage, respectively, and published the draft sequences (2). They suggest that the number of protein-coding genes is 18,000 - 20,000, which is more than that of Drosophila. Based on the EST database, many Bombyx-specific genes, which are not homologous to Drosophila genes, have been found. Therefore, the EST database is a helpful resource for molecular biology of the silkworm and lepidopteran insects.
1. Mita, K. et al. (2003) The construction of an EST database for Bombyx mori and its application. Proc. Natl. Acad. Sci. USA. 100: 14121-14126.
2. Mita, K. et al. (2004) The genome sequence of silkworm, Bombyx mori. DNA Res. 11: 27-35
3. Goldsmith, M. R. et al. (2005) The genetics and genomics of the silkworm, Bombyx mori. Ann. Rev. Entomol. 50: 71-100.
The construction of this database has been supported by
Grant-in-Aid for Publication of Scientific Research Results,
JSPS, Japan (1999-2003, 2005-2015).
The EST sequencing was supported by the Genome Analysis Program,National Bioresource Project (NBRP),
Grants-in-Aid for Scientific Research, MEXT,and the Agrigenome Program, NIAS/MAFF.
The maintenance and distribution of the DNA clones are supported by the National Bioresource Project (NBRP).