Wednesday, November 26, 2003

Zhao et al., "Transgenic plants expressing two Bacillus thuringiensis toxins delay insect resistance evolution," Nature Biotechnology 21/12 (dec. 2003), 1493-7:
Preventing insect pests from developing resistance to Bacillus thuringiensis (Bt) toxins produced by transgenic crops is a major challenge for agriculture. Theoretical models suggest that plants containing two dissimilar Bt toxin genes ("pyramided" plants) have the potential to delay resistance more effectively than single-toxin plants used sequentially or in mosaics. To test these predictions, we developed a unique model system consisting of Bt transgenic broccoli plants and the diamondback moth, Plutella xylostella. We conducted a greenhouse study using an artificial population of diamondback moths carrying genes for resistance to the Bt toxins Cry1Ac and Cry1C at frequencies of about 0.10 and 0.20, respectively. After 24 generations of selection, resistance to pyramided two-gene plants was significantly delayed as compared with resistance to single-gene plants deployed in mosaics, and to Cry1Ac toxin when it was the first used in a sequence. These results have important implications for the development and regulation of transgenic insecticidal plants.
The same issue also reprints the latest ravings of everyone's favorite science fundamentalist -- from the Washington Times:
Although involvement of the public is critical to their understanding of government policy, it is less useful for the formulation of policy. This is particularly true when complex issues of science and technology are involved. Science is not democratic. The citizenry do not get to vote on whether a whale is a mammal or a fish, or on the temperature at which water boils, and legislatures cannot repeal the laws of nature. However, on questions to which there is no scientifically 'right' answer (e.g., at what age can persons drive and vote, or whether we should carry out more manned exploration of the moon), public opinion can play a critical role.
Pretty disturbing bedfellows there, O enlightened ones.

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