Multiple maternal proteins coordinate to restrict the translation of C. elegans nanos-2 to primordial germ cells

• Published in: Development (Cambridge) Vol. 135; no. 10; pp. 1803 - 1812
• Main Authors: Jadhav, Shreyas, Rana, Mainpal, Subramaniam, Kuppuswamy
• Format: Journal Article
• Language: English
• Published: England The Company of Biologists Limited 15.05.2008
• Subjects: 3' Untranslated Regions; Animals; Animals, Genetically Modified; Base Sequence; Caenorhabditis elegans - embryology; Caenorhabditis elegans - genetics; Caenorhabditis elegans - physiology; Caenorhabditis elegans Proteins - biosynthesis; Caenorhabditis elegans Proteins - genetics; Caenorhabditis elegans Proteins - metabolism; Caenorhabditis elegans Proteins - physiology; Carrier Proteins - metabolism; Carrier Proteins - physiology; Cell Cycle Proteins - metabolism; Gene Expression Regulation, Developmental; Germ Cells - metabolism; Germ Cells - physiology; Molecular Sequence Data; Oocytes - growth & development; Oocytes - physiology; RNA-Binding Proteins - metabolism
• ISSN: 0950-1991; 1477-9129
• DOI: 10.1242/dev.013656

Although germ cell formation has been relatively well understood in worms and insects, how germ cell-specific developmental programs are initiated is not clear. In Caenorhabditis elegans, translational activation of maternal nos-2 mRNA is the earliest known molecular event specific to the germline founder cell P 4 . Cis-elements in nos-2 3′UTR have been shown to mediate translational control; however, the trans-acting proteins are not known. Here, we provide evidence that four maternal RNA-binding proteins, OMA-1, OMA-2, MEX-3 and SPN-4, bind nos-2 3′UTR to suppress its translation, and POS-1, another maternal RNA-binding protein, relieves this suppression in P 4 . The POS-1: SPN-4 ratio in P 4 increases significantly over its precursor, P 3 ; and POS-1 competes with SPN-4 for binding to nos-2 RNA in vitro. We propose temporal changes in the relative concentrations of POS-1 and SPN-4, through their effect on the translational status of maternal mRNAs such as nos-2 , initiate germ cell-specific developmental programs in C. elegans .