RNA sorting in Drosophila oocytes and embryos

Many RNAs involved in determination of the oocyte, specification of embryon ic axes, and establishment of germ cells in Drosophila are localized asymme trically within the developing egg or syncytial embryo, Here I review the c urrent state of knowledge about the cis-acting sequences involved in RNA ta rgeting, RNA binding proteins; gene activities implicated in localizing spe cific RNAs, and the role of the tubulin and actin cytoskeletons in RNA sort ing within the oocyte, Targeted RNAs are often under complex translational control, and the translational control of two RNAs that localize to the pos terior of the oocyte, oskar and nanos, is also discussed. Prospects for fil ling gaps in our knowledge about the mechanisms of localizing RNAs and the importance of RNA sorting in regulating gene expression are also explored.