A translation-independent role of oskar RNA in early Drosophila oogenesis

University of Cambridge, Cambridge, England, United Kingdom
Development (Impact Factor: 6.46). 09/2006; 133(15):2827-33. DOI: 10.1242/dev.02456
Source: PubMed


The Drosophila maternal effect gene oskar encodes the posterior determinant responsible for the formation of the posterior pole plasm in the egg, and thus of the abdomen and germline of the future fly. Previously identified oskar mutants give rise to offspring that lack both abdominal segments and a germline, thus defining the ;posterior group phenotype'. Common to these classical oskar alleles is that they all produce significant amounts of oskar mRNA. By contrast, two new oskar mutants in which oskar RNA levels are strongly reduced or undetectable are sterile, because of an early arrest of oogenesis. This egg-less phenotype is complemented by oskar nonsense mutant alleles, as well as by oskar transgenes, the protein-coding capacities of which have been annulled. Moreover, we show that expression of the oskar 3' untranslated region (3'UTR) is sufficient to rescue the egg-less defect of the RNA null mutant. Our analysis thus reveals an unexpected role for oskar RNA during early oogenesis, independent of Oskar protein. These findings indicate that oskar RNA acts as a scaffold or regulatory RNA essential for development of the oocyte.


Available from: Andreas Jenny, Jan 30, 2014
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    • "The example of LDMAR thus links regulation of gametogenesis by an lncRNA to organismal fertility. In the fruit fly Drosophila melanogaster, oogenesis is regulated by the oskar RNA, which has dual coding and noncoding functions (Jenny et al. 2006). Loss of oskar results in sterility due to early arrest of oocyte differentiation, a phenotype that can be rescued by expression of mutant oskar with a disrupted translation capacity. "
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    Molecular Biology of Long Non-coding RNAs,, Edited by Jeff Coller, Ahmad Khalil, 11/2013: chapter 2; Springer.
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    • "In Drosophila, oskar RNA was first characterized as a determinant responsible for formation of the posterior pole plasm in the egg, and thus, formation of the abdomen and germline of the future fly (Markussen et al. 1995). It has since been found that, independent of the protein, oskar mRNA—more specifically its 3′ UTR—has a function that is essential for the completion of oogenesis (Jenny et al. 2006). Recently, Pathak et al. (2013) described transcripts of several hundred nucleotides from the AAGAG repeats of the pericentromeric regions of Drosophila which appear to be critical components of the nuclear matrix. "
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    • "We observed down-regulation of the gene that codes for PPO5; this effect can be linked to the reduced egg production observed or/and with immune effector mechanisms triggered by the CpG-ODN. The expression levels of genes that encode proteins that contain atrophin or oskar motifs, which were previously associated with oogenesis and embryo development in Drosophila (Zhang et al., 2002; Jenny et al., 2006), were altered after CpG-ODN stimulation . This finding strengthens the hypothesis that immunostimulation with CpG-ODN interferes not only with mosquito immunity, but also with mosquito fecundity. "
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