%0 Journal Article %A HAN Guangjie %A XU Linghuan %A LI Chuanming %A LIU Qin %A PENG Qi %A XU Bin %A SONG Fuping %A XU Jian %T Characteristics of Cry and Cyt Proteins and Insecticidal Activity in Bacillus thuringiensis Bt-59 %D 2020 %R 10.16409/j.cnki.2095-039x.2020.03.024 %J Chinese Journal of Biological Control %P 458-464 %V 36 %N 3 %X Bacillus thuringiensis subsp. israelensis (Bti) is an important pathogen for control of mosquito larvae. The types and distribution of toxin proteins are diverse among different strains. In this study, the types and characteristics of toxin genes and insecticidal activity of Bt-59 strain were determined. Bt-59 is different from Bti standard strains in that it harbors a Cry4-like gene and the positions of Cry10Aa and Cyt1Ca are translocated on plasmid 4. The toxin proteins encoded by Cry60Aa and Cry60Ba genes on plasmid 5 contain the ETX_MTX2 domain, showing identity of 100% to homologous proteins of B. thuringiensis subsp. jegathesan. Besides the Bac_thur_toxin domain, Cyt1Ca protein also contains two RicinB_lectin_2 domains in tandem. Bt-59 has high insecticidal activity against mosquito larvae, with LC50 for Aedes albopictus and Culex pipiens pallens of 1.239 μL/L and 0.341 μL/L, respectively. Our research provides a theoretical basis for the genetic improvement of the Bt-59 strain. %U http://www.zgswfz.com.cn/EN/10.16409/j.cnki.2095-039x.2020.03.024