Published online by Cambridge University Press: 17 March 2009
Genetic engineering has quite rightly an image of science fiction. The time when new species with any wanted combination of genetic properties can be ordered from an animal or plant breeding factory seems far away. The layman's view that the science fiction of today is the reality of tomorrow is certainly an insufficient argument to justify optimism. If this were so, we should by now be able to produce hybrids between members of the animal and plant kingdom as was foreseen by a nineteenth-century equivalent of Fred Hoyle (see Fig. I). Despite the scepsis expressed by the prominent scientist Si.r Macfarlane Burnet in his book Genes, Dreams and Realities (1971), recent advances in molecular genetics have raised new enthusiasm (and uneasiness) which make people speak of genetic engineering as something to aim at as an approach to correct inborn errors of metabolism. This will, however, not be our principal dish if we restrict ourselves to a vegetarian menu. We view genetic engineering of plants not only as a future method to improve species, but also as a fundamental approach to the study of gene expression, especially with respect to cell differentiation. If we consider the term literally, the definition of genetic engineering might be any intentional genetic manipulation to alter species or to make new ones. In this sense genetic engineering was practised long before Mendel presented his laws (1865). In the seventeenth century the bulb growers of the Low Countries produced new varieties of tulips for which prices of a thousand forms each were paid (at the 1636 price index!). We notice here already a strong impact of genetic engineering on society; the so-called crazy tulip trade caused a financial disaster on the Amsterdam stock-exchange comparable to the Wall Street crash in the 1930s.