Complete mitochondrial genome of a hybrid strain of the domesticated silkworm (Qiufeng × Baiyu).

The hybrid strain of the domesticated silkworm (Qiufeng x Baiyu) is one of the most popular commercial silkworm varieties in China. In this study, we reported its complete mitochondrial genome sequence for the first time. The 15,680 bp long genome contains 37 genes (13 protein-coding genes [PCGs], 2 rRNA genes, and 22 tRNA genes) and 1 major non-coding A + T-rich region, with the typical arrangement found in Lepidoptera. All PCGs started with typical ATN codons except for COI, which began with CGA. Eleven PCGs have complete stop codons, whereas COI and COII end with a single T. The 495 bp long A + T-rich region harbors the conserved sequence features typically found in lepidopteran insects. The complete mitochondrial genome sequence of Qiufeng x Baiyu provides an important data source for further study on the mechanism of silkworm domestication.