Figure 2.

The germline cycle in Caenorhabditis elegans. The first four cell divisions after fertilization are asymmetric, with the posterior germ line precursor ‘P-cells’ (P1 to P4) inheriting germplasm (green). The anterior cells at each division contribute to various somatic lineages (red). The last division at P4 is symmetric and yields Z2 and Z3. Z2/Z3 divide after hatching, and their descendants undergo extensive proliferation and germ cell development (meiosis and gametogenesis). The cycle is repeated after the gametes fuse in the zygote.