Figure 1. Schematic of germline precursor cells, and cell ablation and microarray experiments.

In the C. elegans L1 stage larvae, the gonad and germline consist of four cells, namely Z1, Z2, Z3 and Z4 with Z(1,4) producing the gonad and Z(2,3) the germline. If Z(2,3) are killed with a laser beam then only somatic gonad tissue is left, and the animals are long-lived. However if Z(1,4) are ablated then the gonad and the germline are both killed as the germline cannot grow without the influence of the gonad [1] and the lifespan of these animals is comparable to un-ablated controls. The different sets of microarray comparisons as described in the text are also indicated.