"Bt" in "Bt" cotton stands for "Bacillus thuringiensis, a soil bacterium from which bt gene (encoding Bt toxin) is obtained. Somatic hybridisation involves the fusion of protoplast (i.e., cell minus cell wall) of two cells. Flavr-savr is a transgenic tomato with hard skin and improved flavour and recombinant hirudin is an anticoagulant which is being produced in transgenic Brassica napas at commercial scale.