[Cloning and mapping of DpKettin gene on Z chromosome of the pine caterpillar by real-time quantitative PCR].

The ratio of Z chromosome number to autosomal chromosome (A) is different between male and female lepidoptera insects. In males: 2Z : 2A=1, and in females: Z : 2A=0.5. The ratio of the copies of gene (such as K) on Z chromosome number to the copies of gene (such as N) on autosomal chromosome (K/N) is also different between male and female. In males: 2K : 2N =1, and in females: K : 2N=0.5. The DpKettin gene of the pine caterpillar Dendrolimus punctatus was cloned with the primers designed according to the sequences of the BmKettin of the silkworm and the HaKettin of the cotton bollworm. The ratio of copies between DpKettin and ANT (adenine nucleotide translocator) in male and female was determined by the real-time quantitative PCR technique. They were 1.0 in males and 0.5 in females. These ratios were equal to the ratios of the copies of gene on Z chromosome number to the copies of gene on autosomal chromosome. It indicates that DpKettin is located on Z chromosome in the genome of the pine caterpillar.