Transcriptional silencing and translational control: key features of early germline development.

The germ lineage has been studied for a long time because of its crucial role in the propagation and survival of a species. While this lineage, in contrast to the soma, is clearly unique in its totipotent ability to produce a new organism, it has now been found also to have specific features at the cellular level. One feature, a period of transcriptional quiescence in the early germ cell precursors, has been observed in both Drosophila and C. elegans, where it is essential for the formation and the survival of the germline. In addition, there are numerous instances where these early germ cells are reliant on translational regulation, especially in Drosophila. The genes that are important for these two functions, the mechanisms of their action, and studies in vertebrate organisms that reveal similarities as well as some potential differences in early germ cell development are discussed. Copyright 2003 Wiley Periodicals, Inc.