Travel and Conference Participation - Pacific Rim Conference on the Biotechnology and Environmental Impact of Bacillus thuringiensis, Victoria, British Columbia.

The evidence points to the Cry toxins having to bind more than one receptor molecule to create the pores that lead to death of the host. In each species tested, a cadherin-like molecule has been identified as one of the receptors. However, the co-receptor may vary between species. Aminopeptidase N, which was the first Cry receptor identified, is important in species like Manduca sexta but in other species (e.g. Heliothis virescens) alkaline phosphatase appears to be important. Glycolipids may also play a role but in what manner is uncertain.

Tabashnik’s group has detected Cry2Ab resistance in pink bollworm. No details were available.

A significant shift in target specificity of a Cry protein has been demonstrated. The putative binding loops of Cry1Aa were modified by protein engineering, converting a lepidopteran-toxic to a dipteran toxin.

Some preliminary work on developing markers through microsatellites for Cry1A resistance in H. armigera was reported. It was not evident that this approach had a great deal to offer.

A value adding approach to was presented. After separating the grains, the rice stems were dried, powered and formulated as a sprayable bioinsecticide for use on other crops.

Herculex®RW, a transgenic maize expressing the Cry34/35 binary toxins, has full regulatory approval for food and stock feed in the USA. Herculex was developed by Dow AgroSciences.