Figure 4.

Examples of four different categories of complementation experiments. Organism A is the donor of the operation of function F, and organism B′, resulting from organism B after knock out of the operation of function F in organism B, is the recipient. Molecular entities are represented by small, coloured geometric symbols. Selected references corresponding to each category of complementation: orthologous replacement [25], non-orthologous replacement [22,24], pathway replacement [23,48] and regulatory complementation [49,51]. Additional examples are provided in table 1.