CGC Bibliography Paper 3175

Genetic requirements for PIE-1 localization and inhibition of gene expression in the embryonic germ lineage of Caenorhabditis elegans.

Tenenhaus C, Schubert C, Seydoux G

Medline:

98370926

Citation:

Developmental Biology 200: 212-224 1998

Type:

ARTICLE

Genes:

apx-1 cib-1 emb-1 emb-3 emb-4 emb-5 emb-6 emb-7 emb-8 emb-11 emb-12 emb-13 emb-16 emb-18 emb-20 emb-21 emb-23 emb-25 emb-26 emb-27 emb-30 emb-31 emb-33 fem-1 fem-3 glp-4 mes-1 mes-2 mes-3 mes-6 mex-1 mex-3 par-1 par-2 par-3 par-4 par-6 pie-1 pop-1 skn-1 zyg-1 zyg-2 zyg-9

Abstract:

In early Caenorhabditis elegans embryos, production of new mRNAs is inhibited in the germ lineage. This inhibition requires the germline factor PIE-1, and correlates with the absence in germline blastomeres of a phosphoepitope on RNA polymerase II (RNAPII-H5). We show that PIE-1 is uniformly distributed in oocytes and newly fertilized eggs, and becomes localized asymmetrically in the late one-cell stage. To begin to dissect the mechanisms required for PIE-1 localization and inhibition of RNAPII-H5 expression, we have examined the distribution of PIE-1 and RNAPII-H5 in maternal-effect mutants that disrupt embryonic development. We find that mutants that disrupt the asymmetric divisions of germline blastomeres mislocalize PIE-1, and activate RNAPII-H5 expression in the germ lineage. In contrast, mutants that alter somatic cell identities do not affect PIE-1 localization or RNAPII-H5 expression. Our observations suggest that PIE-1 represses mRNA transcription in each germline blastomere in a concentration-dependent manner. We also show that in wild-type, and in mutants where PIE-1 is mislocalized, the cellular and subcellular distribution of PIE-1 remarkably parallels that of the P granules, suggesting that the localizations of these two germline components are