Effect of the exotoxin of Bacillus thuringiensis on normal and ecdysone-stimulated ribonucleic acid polymerase activity in intact nuclei from the fat body of Sarcophaga bullata larvae

Abstract

A nuclear preparation from the fat-body of Sarcophaga bullata was obtained which incorporates nucleotides at a steady rate. Two activities, differing in their response to oc-amanitin, are present. The activities are not separated by changes in the concentration of (NH4)2SO4 as effectively as in mammalian nuclei. The activity resistant to a-amanitin is stimulated by ecdysone, and both normal and the ecdysone-stimulated activities are inhibited by the exotoxin. The amanitin-sensitive enzyme is also inhibited by exotoxin, but higher concentrations are required.

Host plant toxicity affects developmental rates in a polyphagous fruit fly: experimental evidence

“…When under natural conditions, S. anguivi is solely infested by stenophagous Ceratitis species of the aliena clade (De Meyer, 2000), and S. mauritianum and M. indica are both natural hosts of C. fasciventris (De Meyer et al, 2002). Based on the presumed relationships between the presence of toxic metabolites and developmental pathways in holometabolous insects (Beebee & Bond, 1973;Thummel & Chory, 2002), we predicted a reduction in the developmental rate, developmental precision, and individual size of F 1 offspring, and also in the subsequent production of F2 offspring during the first 5 weeks of adulthood, with increasing alkaloid concentrations of their host plants.…”

Increase in the resistance to the Bacillus thuringiensis supernatant effect in a Drosophila melanogaster wild type Oregon R line

“…The supernatant of cultures of the Bacillus thuringiensis Berliner strain contains a thermostable toxin (McConnel & Richards, 1959): the beta-exotoxin or thuringiensin, which acts in vivo as a preferential inhibitor of nucleolar RNA polymerase (Mackedonski et al, 1972;Beebee & Bond, 1973). Like the purified toxin, the supernatant has a lethal effect during the development stage if added to the nutritional medium (Paumard & Bourgin-Rosenberg, 1981).…”

Evolutionary Genomics of Bacillus thuringiensis

“…Thuringiensin is a non proteinaceous β-exotoxin and is highly toxic to diverse taxa. It is thermostable and inhibits the eukaryotic DNA-dependant RNA polymerase, which leads to an altered development (Beebee and Bond, 1973). Due to the high toxicity, endochitinases have a supporting effect on Cry/Vip toxins .…”