Comparative mitochondrial genomes provide new insights into the true wild progenitor and origin of domestic silkworm Bombyx mori.

The domestication of domestic silkworm Bombyx mori, the only truly domesticated insect, is a distinctive event in agricultural history. The domestication and origin of domestic silkworm remains unclear, although it has connected with human for ~5500 years. In the present study, we would like to highlight our evidence from whole mitochondrial genome for the presence of two genetically distinctive subtypes in Chinese B. mandarina populations, corresponding to northern Chinese B. mandarina and southern Chinese B. mandarina, respectively. The mitochondrial genomes and mitochondrial phylogenetic tree provide a solid molecular evidence that the true wild ancestor of domestic silkworm is northern Chinese B. mandarina, rather than southern Chinese B. mandarina, thus implying that the early domestication event may have occurred in northern China. Our finding provides new insights into the origin and evolution of domestic silkworm.