title: Physical mapping of the Bacillus thuringiensis subsp. kurstaki and alesti chromosomes.
abstract: Two strains of the well-known insect pathogen and biopesticide, Bacillus thuringiensis (Bt), belonging to subspecies alesti (strain Bt5) and kurstaki (strain Bt213), were chosen for genetic characterization. The two strains belong to different serotypes and are currently classified into different subspecies, although their insecticidal activity is similar. Physical maps were constructed of Bt alesti and Bt kurstaki using Pulsed Field Gel Electrophoreses (PFGE), and the map positions of several genes were determined. The 5.5 Mb combined genetic and physical chromosome maps of the two strains were found to be indistinguishable, and the only differences detected between the strains were of extrachromosomal origin. A cryIA toxin gene probe hybridised to a chromosome fragment and to two extrachromosomal elements in both strains, migrating as 100 kb and 350 kb, respectively. In addition a cry hybridizing extrachromosomal element migrating as 80 kb was present only in Bt alesti. Both strains were also found to contain sequences hybridizing to an enterotoxin (hbla) gene probe. Such sequences were positioned on the 350 kb extrachromosomal element, as well as on the chromosome.
authors.affiliation: Department of Microbiology, Stockholm University, S-106 91 Stockholm, Sweden. ann.lovgren@bioinvent.se
authors.forename: Ann
authors.initials: A
authors.lastname: Lövgren
authors.forename: Cathrine R
authors.initials: CR
authors.lastname: Carlson
authors.forename: Daiwu
authors.initials: D
authors.lastname: Kang
authors.forename: Katarina
authors.initials: K
authors.lastname: Eskils
authors.forename: Anne-Brit
authors.initials: AB
authors.lastname: Kolstø
mesh_terms: D001413:Bacillus thuringiensis / Q000737:chemistry / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001427:Bacterial Toxins; D015139:Blotting, Southern; D002876:Chromosomes, Bacterial / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D004731:Endotoxins / Q000737:chemistry / Q000235:genetics; D006460:Hemolysin Proteins; D020161:Physical Chromosome Mapping
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004731:Endotoxins; D006460:Hemolysin Proteins; C083961:hemolysin BL protein, Bacillus; C030956:insecticidal crystal protein, Bacillus Thuringiensis