Positional cloning in arabidopsis. Why it feels good to have a genome initiative working for you

Positional (or map-based) cloning techniques are widely used to identify th e protein products of genes defined by mutation. In Arabidopsis the informa tion generated by the Genome Initiative is giving this approach a decisive boost. A wealth of sequence polymorphisms and molecular markers is now avai lable and can be exploited for fine mapping with technically simple and rob ust polymerase chain reaction-based methods. As a result it has become poss ible to complete positional cloning projects in a short time and with relat ively little effort.