First published online April 16, 2004
Journal of Cell Science 117, 1002e (2004)
© The Company of Biologists Limited
Nuage traveller not part of polar expedition
Nuage particles are unique, germ-line-specific organelles thought to contain germ-cell determinants. In females, these particles disappear when oocytes are specified but remain in nurse cells. Oocytes later accumulate structures termed polar granules at their posterior poles. These are also associated with determinants and contain proteins found in nuage particles, such as Vasa, Tudor and Aubergine. A widely held view has therefore been that nuage particles represent precursors of polar granules. Using live-cell imaging of GFP-tagged Vasa and Aubergine, Mark Snee and Paul Macdonald now challenge this idea (see p. 2109). They find that nuage particles form stable perinuclear structures in nurse cells and seldom move away into the cytoplasm. Those that do move can enter the oocyte through ring canals but do not become anchored at the posterior or incorporated into polar granules. Instead assembly of polar granules appears to be initiated de novo by Oskar — an anchor protein not present in nuage particles — which recruits components from the cytoplasmic pool. Since nuage particles contain the translational repressor Bruno and are located close to nuclear pores, the authors propose that these particles might function in post-transcriptional regulation of newly exported mRNAs.
Related articles in JCS:
- Live imaging of nuage and polar granules: evidence against a precursor-product relationship and a novel role for Oskar in stabilization of polar granule components
- Mark J. Snee and Paul M. Macdonald
JCS 2004 117: 2109-2120.
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