title: Isolation and characterization of a novel insecticidal crystal protein gene from Bacillus thuringiensis subsp. aizawai.
abstract: Bacillus thuringiensis subsp. aizawai EG6346, a novel grain dust isolate, was analyzed by Southern blot hybridization for its insecticidal crystal protein (ICP) gene profile. Strain EG6346 lacks previously characterized cryIA ICP genes yet does possess novel cryI-related gene sequences. A recombinant genomic plasmid library was constructed for strain EG6346 in Escherichia coli. One recombinant plasmid, pEG640, isolated from the library contained a novel ICP gene on a 5.7-kb Sau3A insert. The sequence of this gene, designated cryIF, was related to, but distinct from, the published sequences for other cryI genes. A second novel cryI-related sequence was also located on pEG640, approximately 500 bp downstream from cryIF. Introduction of cryIF into a Cry- B. thuringiensis recipient strain via electroporation enabled sufficient production of CryIF protein for quantitative bioassay analyses of insecticidal specificity. The CryIF crystal protein was selectively toxic to a subset of lepidopteran insects tested, including the larvae of Ostrinia nubilalis and Spodoptera exigua.
authors.affiliation: Ecogen Inc., Langhorne, Pennsylvania 19047.
authors.forename: J A
authors.initials: JA
authors.lastname: Chambers
authors.forename: A
authors.initials: A
authors.lastname: Jelen
authors.forename: M P
authors.initials: MP
authors.lastname: Gilbert
authors.forename: C S
authors.initials: CS
authors.lastname: Jany
authors.forename: T B
authors.initials: TB
authors.lastname: Johnson
authors.forename: C
authors.initials: C
authors.lastname: Gawron-Burke
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000633:toxicity; D001427:Bacterial Toxins; D001483:Base Sequence; D003001:Cloning, Molecular; D004731:Endotoxins; D005798:Genes, Bacterial; D006460:Hemolysin Proteins; D007915:Lepidoptera / Q000187:drug effects* / Q000382:microbiology; D008969:Molecular Sequence Data; D010957:Plasmids; D011994:Recombinant Proteins / Q000235:genetics; D015183:Restriction Mapping
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D011994:Recombinant Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis