To date insect resistance has been provided by a gene from the soil bacterium bacillus thuringiensis bt this gene directs cells to manufacture a crystalline protein that is toxic to certain insects especially caterpillars and beetles that gnaw on crops 这个基因会促使细胞制造一种晶体状蛋白质，对某些昆虫来说是毒药，尤其是啃食作物的毛毛虫和甲虫，却不会伤害其他生物。
