Uses and abuses of genetic engineering

• genetic engineering

Genetic engineering refers to the techniques whereby recombinant DNA, hybrid DNA made by artificially joining pieces of DNA from different sources, is produced and utilised. The term has gradually broadened out from this earlier more stringent definition to encompass virtually any process involving DNA manipulation. The applications of genetic engineering are now so widespread and well established within the biomedical sciences that it is difficult for younger investigators to envisage what research life was like in the era before genetic engineering. A quick skim of the articles in the current issue of the Journal of Immunology, a journal that ranges from clinical perspectives to molecular characterisation, reveals that out of 79 articles no less than 65 (82%) utilised genetic engineering as an important component of their investigation. In the more molecular journals that figure would certainly be 100% and even in the most clinical journals genetic engineering utilisation is prominent. This helps to explain why biomedical research laboratories around the world now tend to look so similar: irrespective of the precise discipline involved, the widespread use of molecular biology imposes its own constraints upon architecture and, indeed, on the sociology of scientific communities.

The publication of the mouse genome sequence in late 2002 highlighted the enormous importance of the mouse as a model for human disease.1 Of the roughly 30 000 genes present in both human and mouse, 99% of the human genes have homologues in the mouse genome (and vice versa). In practice what this means is that nearly all the genes that contribute to human disease can be studied in the mouse, although of course gene function is not necessarily identical in the two contexts. Deleting genes out of mice (“making knockouts” in laboratory jargon) and over-expressing genes in particular lineages (“making …