苏云金芽胞杆菌鲇泽亚种HD-133 cry1D和cry1 Ab mRNA含量及稳定性研究

Sduty on Amount and Stability of cry1D and cry1Ab mRNAin Bacillus thuringiensis subps aizawai

苏云金芽胞杆菌鲇泽亚种菌株HD 1 3 3含有代表性的三种cry1类基因cry1Ab,cry1C和cry1D ,它们的表达量却明显不同。通过Northern杂交检测了菌株HD 1 3 3中基因cry1D和cry1Ab的mRNA含量及其稳定性。结果表明 :基因cry1DmRNA的形成比基因cry1Ab的mR NA滞后 3h ,且基因cry1D形成mRNA的量很低 ,产生过程很平稳 ,在芽胞形成中期比cry1AbmRNA低 3 7倍 ;cry1AbmRNA含量在芽胞形成前期高于后期 ,在后期仍能大量持续稳定地转录。cry1DmRNA的半衰期为 1 8min,而cry1AbmRNA的半衰期为 1 4min。尽管cry1DmRNA比cry1AbmRNA的半衰期更长 。

cry1Ab, cry1C and cry1D are three typical cry1 class genes encoding protoxins in Bacillus thuringiensis subsp.aizawai strain HD-133. The expression of cry1D is obviously different from that of cry1Ab in this strain. Amount and stability of cry1D and cry1Ab mRNA in HD-133 were investigated. Northern blotting analysis showed that cry1D mRNA was more stable than cry1Ab mRNA, however, cry1D mRNA formed later 3h and less 3.7 times than cry1Ab mRNA during the mid-phase of sporulation. Halve lives of cry1D mRNA was 18min,but halve lives of cry1Ab mNRA was 14min. Moreover, cry1Ab mRNA could keep stable and large amount during the post-phase of sporulation. This suggested that difference of transcriptional efficiency and initiate time might be main reason for the difference of expression of cry1Ab and cry1D.