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Control of cell fate by the fem-3 3'untranslated region in the nematode Caenorhabditis elegans

Applicant Puoti Alessandro
Number 67052
Funding scheme Project funding (Div. I-III)
Research institution Département de Biologie Faculté des Sciences Université de Fribourg
Institution of higher education University of Fribourg - FR
Main discipline Embryology, Developmental Biology
Start/End 01.04.2002 - 30.09.2007
Approved amount 377'000.00
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Keywords (6)

RNA; CELL FATE; Nematode; Germ line; oogenesis; post-transcriptional regulation

Lay Summary (English)

Lay summary
In the protandric nematode Caenorhabditis elegans, the fem-3 mRNA is repressed to allow the switch from sperm to oocyte production. The regulation of the fem-3 mRNA represents an attractive approach to study post-transcriptional control in a genetically well-established model organism. fem-3 is repressed by number of trans-acting factors, such as the FBF proteins and six mog genes. The mog genes and their characterization has lead to the discovery of four nuclear MOG proteins that bear homologies to enzymes that are more or less closely related to splicing factors or to proteins that function in RNA metabolism. We have now completed the first step of the characterization of MOG-3 by examining its expression pattern, its mutant allele analysis, and by uncovering several proteins that bind to MOG-3. Among these, we found MEP-1 and CIR-1 to bind directly to MOG-3. MEP-1 is a nuclear zinc finger protein that binds to other MOG proteins and that is necessary for oogenesis and more generally for the distinction between germ line and somatic cell fates. CIR-1 is homologous to a co-repressor of Notch signalling and its mammalian homologue acts in a complex that silences the transciption factor CBF1. In worms, we have found that cir-1 is required for meiosis in the oocyte but not in the sperm. Similarly, we have found that MOG-3 is not only required for the switch from spermatogenesis to oogenesis, but also for meiosis in general. Therefore mog-3 and cir-1 might act in concert for oogenic meiosis. This finding is provocative, since the worm CBF1 homologue LAG-1 plays a crucial role in the proliferation of germ cells by promoting mitosis. We have recently cloned mog-2 and found that it also encodes a nuclear protein. In contrast to the other MOG proteins, MOG-2 behaves in a different manner. In fact, MOG-2 does not bind to MEP-1 and does not meet the same requirements for its role in meiosis. The molecular role of mog-2 is under investigation.
Direct link to Lay Summary Last update: 21.02.2013

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Associated projects

Number Title Start Funding scheme
55384 Control of cell fate by the fem-3 3'untranslated region in the nematode Caenorhabditis elegans (zu START) 01.01.1999 Project funding (Div. I-III)