Sequence and Expression of Two <b><i>cry8</i></b> Genes from <b><i>Bacillus thuringiensis</i></b> INTA Fr7-4, a Native Strain from Argentina

Abstract

We found and characterized two cry8 genes from the Bacillus thuringiensis strain INTA Fr7-4 isolated in Argentina. These genes, cry8Kb3 and cry8Pa3, are located in a tandem array within a 13,200-bp DNA segment sequenced from a preparation of total DNA. They encode 1,169- and 1,176-amino-acid proteins, respectively. Both genes were cloned with their promoter sequences and the proteins were expressed separately in an acrystalliferous strain of B. thuringiensis leading to the formation of ovoid crystals in the recombinant strains. The toxicity against larvae of Anthonomus grandis Bh. (Coleoptera: Curculionidae) of a spore-crystal suspension from the recombinant strain containing cry8Pa3 was similar to that of the parent strain INTA Fr7-4.

Complete Sequence and Organization of pFR260, the <b><i>Bacillus thuringiensis</i></b> INTA Fr7-4 Plasmid Harboring Insecticidal Genes

“…These plasmids have in common the lack of an insecticidal gene. Nevertheless, we found 3 cry8 genes in this strain, although their localization in the complete genome remains unknown [Amadio et al, 2013;Navas et al, 2014]. The product of one of these genes, i.e., Cry8Pa3 [Navas et al, 2014], showed significant toxicity against the coleopteran pest of cotton, i.e., Antonomus grandis.…”

“…Nevertheless, we found 3 cry8 genes in this strain, although their localization in the complete genome remains unknown [Amadio et al, 2013;Navas et al, 2014]. The product of one of these genes, i.e., Cry8Pa3 [Navas et al, 2014], showed significant toxicity against the coleopteran pest of cotton, i.e., Antonomus grandis. In this paper, we present the complete sequence and analysis of pFR260, a megaplasmid from B. thuringiensis INTA Fr7-4 that encodes the 3 previously described cry8 genes of this strain.…”

“…We have previously identified 3 cry genes (i.e., cry8Qa2 , cry8Kb3, and cry8Pa3 ) in B. thuringiensis strain INTA Fr7-4 and showed that each gene encodes a protein able to produce crystals when it is expressed individually in a recombinant acrystaliferous strain [Amadio et al, 2013;Navas et al, 2014]. The 3 reported plasmids of this strain do not contain any cry8 gene.…”

“…pFR260_163, pFR260_170, and pFR260_212 encode the respective proteins Cry8Kb3 , Cry8Pa3, and Cry8Qa2, which have been characterized previously [Amadio et al, 2013;Navas et al, 2014].…”

“…thuringiensis INTA Fr7-4 is a strain isolated from a soil sample from the province of Misiones, Argentina. It produces ovoid crystals with different levels of toxicity to Lepidoptera and Coleoptera [Amadio et al, 2013;Navas et al, 2014]. We previously reported the complete sequence of 3 plasmids of this strain, named pFR12, pFR12.5, and pFR55 according to their molecular weight in kilo-base pairs [Amadio et al, 2009].…”