Nature reveals how a mosquito-killing gene technique is being used to create better silk more efficiently:
But male silkworms (Bombyx mori) are much more useful for farmers: they are more resistant to disease, eat less and produce better silk, says Luke Alphey, chief scientific officer at Oxitec, a biotechnology company based in Abingdon, UK. At present, separating males from females is impractical.
In a paper in the Proceedings of the National Academy of Sciences, the researchers describe how they genetically modify silkworms to produce a deadly build-up of a protein called tTAV. And by exploiting some of the genes that determine whether an animal is male or female, they ensure that this protein is expressed only in females. When silk farmers need the animals to breed normally, they can turn off the lethal switch simply by feeding the grubs an antibiotic called tetracycline.