title: The distribution pattern of DNA and protoxin in Bacillus thuringiensis as revealed by laser confocal microscopy analysis.
abstract: It was reported that the parasporal crystal from Bacillus thuringiensis contained DNA fragments. To investigate the distribution of protoxin and DNA in B. thuringiensis cells at different growth stages, a cry1Ac-gfp fusion gene was constructed and expressed in an acrystalliferous B. thuringiensis strain, in which the localization of DNA and protoxin were indicated by DNA-specific dye and green fluorescent protein, respectively. When the recombinant cells were at the vegetative growth stage, the Cry1Ac-GFP fusion protein was not expressed and the DNA fluorescent signal was evenly distributed throughout the cell. At the initial stage of sporulation, the Cry1Ac-GFP fusion protein was expressed and accumulated as inclusion body, while two condensed DNA signals existed at each pole of the cell. With the extension of culture time, it seemed that the DNA fluorescence from the region of spore development gradually became faint or vanishing, while the DNA signal was still present in the other pole or the remaining area of the mother cell. Interestingly and unexpectedly, there was no DNA fluorescence signal in the region of the growing and mature inclusion body of Cry1Ac-GFP in B. thuringiensis cell, which might indicate that the DNA embodied in the inclusion body was not accessible to the DNA-specific dye. This was the first investigation devoted exclusively to the in vivo distribution of protoxin and DNA in B. thuringiensis at different growth stages. These data shed light on deeply understanding the process of sporulation and parasporal crystal formation as well as further exploring the interaction of DNA and protoxin in B. thuringiensis.
authors.affiliation: College of Life Science, Hunan Normal University, Changsha, 410081, People's Republic of China.
authors.forename: Quanfang
authors.initials: Q
authors.lastname: Hu
authors.forename: Jingfang
authors.initials: J
authors.lastname: Wang
authors.forename: Zujiao
authors.initials: Z
authors.lastname: Fu
authors.forename: Xiangtao
authors.initials: X
authors.lastname: Mo
authors.forename: Xuezhi
authors.initials: X
authors.lastname: Ding
authors.forename: Liqiu
authors.initials: L
authors.lastname: Xia
authors.forename: Youming
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yunjun
authors.initials: Y
authors.lastname: Sun
mesh_terms: D001413:Bacillus thuringiensis / Q000737:chemistry* / Q000235:genetics; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis*; D004731:Endotoxins / Q000032:analysis* / Q000235:genetics; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006460:Hemolysin Proteins / Q000032:analysis* / Q000235:genetics; D018613:Microscopy, Confocal; D011498:Protein Precursors / Q000032:analysis* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004731:Endotoxins; D006460:Hemolysin Proteins; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D049452:Green Fluorescent Proteins