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8. Materials and methods are available as supporting
material on Science Online.
9. C. A. Russo, N. Takezaki, M. Nei, Mol. Biol. Evol. 12, 391
10. G. Dietzl et al., Nature 448, 151 (2007).
11. K. Keleman, T. Micheler, VDRC project members, Personal
communication to FlyBase, FBrf0208510: RNAi-phiC31
construct and insertion data submitted by the Vienna
Drosophila RNAi Center (2009); http://fb2010_07.
12. A. L. Parks et al., Nat. Genet. 36, 288 (2004).
13. C. Joppich, S. Scholz, G. Korge, A. Schwendemann,
Chromosome Res. 17, 19 (2009).
14. H. Ida et al., Nucleic Acids Res. 37, 1423 (2009).
15. J. L. Mueller, J. L. Page, M. F. Wolfner, Genetics 175, 777
(2007). Germ cells: Do P granules contain the
determinant? Cytoplasmic Partitioning of P Granule
Components Is Not Required to
Specify the Germline in C. elegans
Christopher M. Gallo,* Jennifer T. Wang,* Fumio Motegi, Geraldine Seydoux†
Asymmetric segregation of P granules during the first four divisions of the Caenorhabditis
elegans embryo is a classic example of cytoplasmic partitioning of germline determinants. It is
thought that asymmetric partitioning of P granule components during mitosis is essential to
distinguish germline from soma. We have identified a mutant (pptr-1) in which P granules become
unstable during mitosis and P granule proteins and RNAs are distributed equally to somatic and
germline blastomeres. Despite symmetric partitioning of P granule components, pptr-1 mutants
segregate a germline that uniquely expresses P granules during postembryonic development.
pptr-1 mutants are fertile, except at high temperatures. Hence, asymmetric partitioning of
maternal P granules is not essential to specify germ cell fate. Instead, it may serve to protect
the nascent germline from stress. A general characteristic of germ cells 1685.
Gallo et al (2010). Science 330, is the rhabditis elegans, germ (P) granules are present
presence of cytoplasmic RNA-rich granules called germ granules (1). In Caeno- Germ cells: P granules & PIE-1
segregate to the posterior 16. N. Perrimon, A. Lanjuin, C. Arnold, E. Noll, Genetics 144,
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