Cell Division and Reproduction
- Julien DUMONT
Tel.: +33 (0)157278049
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Worldwide it is estimated that 15% of couples have problems conceiving. One potential explanation for the recent decline in human fertility is a poor quality of germ cells or gametes (spermatozoids and oocytes). A major challenge for biologists is to understand the cause of this reduction in gametes quality.
A likely primary cause for poor germ cell quality is aneuploidy (a wrong number of chromosomes in the cell). Indeed, the vast majority of embryos formed from aneuploid gametes are non-viable and lead to spontaneous abortion. A few aneuploid embryos are viable, but lead to lifelong conditions such as Trisomy 21/Down Syndrome (due to an extra chromosome 21) with a prevalence of ~1:1000 live births in the general population. Aneuploidy usually arises from errors in the process of chromosome segregation during cell division.
Our project aims at understanding the mechanisms that promote production of oocytes with a correct number of chromosomes, which is essential for the generation of viable and normal embryos and thus for successful reproduction. We use a multidisciplinary approach that combines genetics, cell biology, cutting edge microscopy technics and the use of the powerful Caenorhabditis elegans model system.
Montage illustrating the different steps of chromosome segregation during the first meiotic division of the C. elegans oocyte.
In C. elegans, a microtubule-based spindle (green) assembles during meiotic division and promotes chromosome (red) alignment on a metaphase plate (1). Spindle poles then shrink around chromosomes (2). Finally, during anaphase, microtubules concentrate between the separating chromosomes and ‘push’ them toward the two future daughter cells (3).
Sélection de publications
Maton, G.*, Edwards, F.*, Lacroix, B., Stefanutti, M., Laband, K., Lieury, T., Kim, T., Espeut, J., Canman, J.C., & Dumont, J.
Kinetochore components are required for central spindle assembly
Nat Cell Biol 17(5):697-705 (2015). (*co-first authors)
Aurora B/C in Meiosis: Correct Me If I’m Right
Dev Cell 33, 499-501 (2015).
Davies, T., Jordan, S.N., Chand, V., Sees, J.A., Laband, K., Carvalho, A., Shirasu-Hiza, M., Kovar, D., Dumont, J., & Canman, J.C.
High-Resolution Temporal Analysis Reveals a Functional Timeline for the Molecular Regulation of Cytokinesis.
Dev Cell. 2014 Jul 28;30(2):209-223.
Gomes, J.E., Tavernier, N., Richaudeau, B., Formstecher, E., Boulin, T., Mains, P.E., Dumont, J. & Pintard, L.
Microtubule-severing by the Katanin complex is activated by PPFR-1-dependent MEI-1 dephosphorylation.
J Cell Biol 202, 431-439 (2013).
Dumont, J. & Desai, AB.
Spindle assembly and chromosome segregation during meiosis.
Trends in Cell Biology 22(5):241-9. (2012).
Last modified 7 April 2017