A history of chromosome identification in Bombyx mori

The silkworm, Bombyx mori, is a lepidopteran model with long history of the domesticated insect for silk production, which contributed to human life as well as insect sciences. In chromosome science, the silkworm could be the first record of karyotype count in Lepidoptera. Because of the holokinetic chromosomes, precise chromosome identification and karyotype had been difficult until BAC-FISH (fluorescence in situ hybridization with bacterial chromosome (BAC) DNAs as probes) was applied for the silkworm chromosome analysis. Here we review the research histories for the first B. mori karyotype and its contribution for chromosome science and comparative genomics in Lepidoptera.