Open AccessGeneration of mariner ‐based transposon insertion mutant library of B acillus sphaericus 2297 and investigation of genes involved in sporulation and mosquito‐larvicidal crystal protein synthesis
Author(s) -
Wu Yiming,
Hu Xiaomin,
Ge Yong,
Zheng Dasheng,
Yuan Zhiming
Publication year - 2012
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2012.02539.x
Subject(s) - bacillus sphaericus , transposable element , mutant , biology , gene , spore , genetics , microbiology and biotechnology , bacillales , bacteria , bacillus subtilis
B acillus sphaericus has been used with great success in mosquito control programs worldwide. Under conditions of nutrient limitation, it undergoes sporulation via a series of well defined morphological stages. However, only a small number of genes involved in sporulation have been identified. To identify genes associated with sporulation, and to understand the relationship between sporulation and crystal protein synthesis, a random mariner ‐based transposon insertion mutant library of B . sphaericus strain 2297 was constructed and seven sporulation‐defective mutants were selected. Sequencing of the DNA flanking of the transposon insertion identified several genes involved in sporulation. The morphologies of mutants were determined by electron microscopy and synthesis of crystal proteins was analyzed by SDS ‐ PAGE and Western blot. Four mutants blocked at early stages of sporulation failed to produce crystal proteins and had lower larvicidal activity. However, the other three mutants were blocked at later stages and were able to form crystal proteins, and the larvicidal activity was similar to wild type. These results indicated that crystal protein synthesis in B . sphaericus is dependent on sporulation initiation.