ABSTRACTLimiting maternal resources necessitates deferring the development of adult-specific structures, notably the reproductive structures, to the postembryonic phase. These structures form postembryonically from blast cells generated during embryogenesis. A close coordination of developmental timing and pattern among the various postembryonic cell lineages is essential to form a functional adult. Here, we show that theC. elegansgenegvd-1is essential for the development of several structures that form during the late larval stages. Ingvd-1mutant animals, blast cells that normally divide during the late larval stages (L3 and L4) fail to divide. In addition, germ cell proliferation is also severely reduced in these animals. Expression patterns of relevant reporter transgenes revealed a delay in G1/S transition in the vulval precursor cell P6.p and cytokinesis failure in seam cells ingvd-1larvae. Our analyses of GVD-1::GFP transgenes indicate that GVD-1 is expressed in both soma and germ line, and functions in both. Sequence comparisons revealed that the sequence ofgvd-1is conserved only among nematodes, which does not support a broadly conserved housekeeping function forgvd-1. Instead, our results indicate a crucial role forgvd-1that is specific to the larval development of nematodes.