Establishment and characterization of a new embryonic cell line from the silkworm, Bombyx mori

Insect cell lines are widely used for basic and applied research in the fields of insect pathology, genetics, and molecular biology. In the present study, a new continuous cell line designated BmE-SWU3 was established from blastokinesis-stage embryos of the silkworm Bombyx mori (Furong strain). The primary culture was initially performed using Grace’s medium supplemented with 20 % foetal bovine serum (FBS) at a constant temperature of 27 °C. The dominant cell type was round and spindle-shaped. Thus far, this cell line has been cultured continuously for 60 passages. The cell doubling time was approximately 3.0 days. The SSR profile of BmE-SWU3 differs from those of the silkworm BmE and BmN-SWU1 cell lines and from those of the Spodoptera frugiperda cell line Sf9 and the Drosophila cell line S2. However, the SSR profiles among the various passages of BmE-SWU3 were stable and identical. This new cell line was highly susceptible to Bombyx mori nucleopolyhedrovirus (BmNPV). Semi-quantitative RT-PCR indicated that the tissue-specific gene expression patterns were completely distinct from those of BmE and BmN-SWU1.