Repressive translational control in germ cells.

The earliest stages of embryonic development in many animals proceed without zygotic transcription. Genetic control is executed by maternally inherited mRNAs that are under translational control. To set aside the future germ cell lineage, it is pivotal to both exert translational regulation of maternal germline mRNAs and to repress maternal signals in those same cells that drive somatic cell-fate determination. Here we review repressive translational regulation in the germline from the perspective of the conserved RNA binding proteins Pumilio and Nanos, and discuss common themes that have emerged.