The aims of this project were two-fold. Firstly, we intended to isolate, characterise and test r genetic elements which control genes expressed at very high levels in the cotton fibre but at low levels elsewhere in the plant. We obtained seven such elements, three of which were shown to be fibre-specific in cotton transfonnation experiments. These important elements are now available for further research and engineering of the fibres, as they allow expression of genes (such as pigment or pest resistance genes) just in fibre cells. A second aim was to target and isolate genes which had not been isolated from cotton, but which, based on data from other plant systems, we suspected would be important in fibre development. We isolated and characterised several such genes, many of which are regulatory, that is, control the expression of other genes, and may have a role in the initiation of cotton fibre growth. This significant preliminary analysis has put us in a position to test these genes, in order to r identify the best candidate(s) for manipulation of cotton fibre characteristics and yield.