Rights: The University of Waikato Published 1 December 2005 Download

At AgResearch, scientists are modifying a parasitic worm that infects possums. The modified worm will be able to seriously reduce the fertility of possums that it infects. Dr. Warwick Grant explains that foreign DNA is injected into the ovaries of a female nematode. The baby nematodes that carry the foreign DNA (the 'transgene') are then selected and used for further research and testing.


Dr Warwick Grant (AgResearch)
Making transgenic nematodes is actually conceptually very simple and technically kind of demanding. The way that most transgenic animals are made these days, like transgenic mice or transgenic cattle or whatever, is to take the DNA that you want to insert, your transgene that you want these animals to express for you, and you inject that into the nucleus of the egg. With the nematode, nematodes are really small and their eggs are smaller still and so injecting into the nucleus of a nematode egg is really tricky. However, fortunately for us it is good enough to just inject this DNA into the ovary of the nematode. So the way that we make our transgenic nematodes is we get the DNA that we want to insert, we put it into a really small needle, and inject that into the ovary of our nematodes, and then we look amongst the babies produced by that injected mother nematode for babies that came from an egg where some of that DNA stuck. And those babies are the transgenic ones or the genetically manipulated ones.