1. State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China P.R.
2. College of Food Science, Southwest University, Chongqing 400715, China P.R.
3. Biological Science Research Center, Southwest University, Chongqing, China P.R.
4. Agriculture and Agri-Food Canada, Government of Canada, Lacombe Research and Development Centre, 6000 C&E Trail, Lacombe, Alberta T4L 1W1, Canada