Rapid identification of Bombyx mori cells using PCR amplification following a direct procedure for genomic DNA preparation

In cultured cells, karyotypes and genomic dose are variable, especially in ones passaged for a long time. We have improved a method for the genome confirmation of cultured cells of the silkworm, Bombyx mori. A rapid, simple procedure was developed for direct extraction of genomic DNA from cultured cells which has two main steps of proteinase K treatment and heating, without phenol extraction. Genomic characterization is based on PCR amplification of three known genes which vary in copy number and chromosome location. The retrotransposon, BMC1, is dispersed in the genome; rDNA is clustered in one locus; and the fibroin gene is single copy. These genes were sufficient to identify cells as Bombyx mori for comparing among the other species. It was shown that this method could also be used for genotyping and strain identification using larval hemolymph samples.