Two delta-endotoxin genes, cry9Da and a novel related gene, commonly occurring in Lepidoptera-specific Bacillus thuringiensis Japanese isolates that produce spherical parasporal inclusions.
Six Lepidoptera-specific Bacillus thuringiensis isolates, which belong to the four H serovars (sotto, fukuokaensis, canadensis, and galleriae) and produce spherical parasporal inclusions, were examined for assignment of the classes of the delta-endotoxin genes. Gene analysis was conducted by PCR technique with primers designed to probe the genes cry9Ca and cry9Da. The data revealed that the delta-endotoxin of a serovar canadensis isolate is encoded by the gene cry9Da, while those of the five other strains are encoded by an undescribed delta-endotoxin gene. DNA fragments from five strains had an identical 1917-bp nucleotide sequence, covering the four conserved regions and a partial sequence of the block 5 region. The deduced amino acid sequence exhibited a 70.6% homology to that of the corresponding region of the Cry9Ea delta-endotoxin protein which is active on the order Lepidoptera, and a 63.1% homology to the Cry9Ca protein highly toxic to the noctuid lepidopterans. The results showed that Japanese isolates of B. thuringiensis producing spherical parasporal inclusions with Lepidoptera-specific activity are categorized into two groups: one produces the class Cry9Da protein and the other a novel delta-endotoxin allied to the class Cry9. It also appeared that heterogeneous multiple H serovars are involved in each group.
Wasano
N
N
Bioresources and Management Lab, Graduate School of Agriculture, Kyushu University, Fukuoka 812-8581, Japan. wasano@agr.kyushu-u.ac.jp
Ohba
M
M
Miyamoto
K
K
D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics* / Q000472:pathogenicity* / Q000648:ultrastructure; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins; D004731:Endotoxins / Q000235:genetics*; D005798:Genes, Bacterial; D006460:Hemolysin Proteins; D007564:Japan; D007915:Lepidoptera / Q000382:microbiology*; D008969:Molecular Sequence Data; D013045:Species Specificity; D013171:Spores, Bacterial / Q000648:ultrastructure
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis