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Germ Cell Development
U934/UMR3215 – Genetics and Developmental Biology
Jean-René Huynh
Chef d'équipe
Tel: +33 (0)1 56 24 69 47
Germ cells are the only cells which are transmitted from
one generation to the next and can be considered
immortal. Germ cells produce highly specialized cells,
called gametes, which carry the genetic and cytoplasmic
information defining a given species and which can
initiate the formation of an entire organism.
Understanding how germ cells develop is not only of paramount medical interest for
reproductive medicine, but is also crucial to comprehend how animal shapes and forms evolve
through generations. Drosophila adult females present several key advantages as a model
system to study germ cell development. In each ovary, there are germline stem cells (GSCs),
which produce eggs (the female gamete) throughout the female life. It is thus possible to follow
the entire development of germ cells from stem cell to fertilized egg in a single fly. Drosophila
geneticists also keep on generating ever-more refined tools to control the function of every gene
in the genome. It is for example possible to switch off one specific gene in germ cells at one
precise time.
In females, GSCs are located at the anterior apex of a specialized structure called the
germarium. GSCs divide asymmetrically leading to the formation of a self-renewing GSC and a
differentiating cystoblast. The cystoblast then undergoes four rounds of asymmetric divisions
with incomplete cytokinesis, leading to the formation of a cyst of 16 germline cells
interconnected by cytoplasmic bridges called ring canals. Only one cell becomes the egg and
goes through meiosis, while the 15 remaining cells become polyploidy nurse cells. Despite
representing an excellent model system to study stem cell biology, cell cycle control, meiosis,
cell fate determination or cell polarity, the germarium remains poorly explored. Our lab has
taken a forward genetic strategy to find the genes regulating these different processes. We have
mutagenized randomly the genome and generated mutant lines, which are defective in the
formation of the germline. Based on this collection of mutants, we address the following
questions:
1) How is germline stem cell growth regulated? GSCs divide actively and need to recover their
initial volume/mass quickly after each division. We found that specialized mechanisms are
INSTITUT CURIE, 20 rue d’Ulm, 75248 Paris Cedex 05, France | 1
Germ Cell Development
U934/UMR3215 – Genetics and Developmental Biology
involved.
2) How is the duration of cytokinesis regulated in germ cells? We identified mutations in
Drosophila Aurora-B and Cyclin-B genes, which regulate complete abscission in germline stem
cells and incomplete abscission in differentiating germ cells.
3) How do homologue chromosomes find each other during meiosis? We are studying the
potential role of the cytoplasmic cytoskeleton in regulating chromosome organization during the
early steps of meiosis in the germarium.
4) How is the germline genetic material protected from DNA damages? The genetic information
contained in the female gamete needs to be safely transmitted to the next generation. We are
studying how mobile DNA elements such as transposons are silenced in germline cells.
Key publications
Year of publication 2015
Anahi Molla-Herman, Ana Maria Vallés, Carine Ganem-Elbaz, Christophe Antoniewski, Jean-René
Huynh (2015 Oct 17)
tRNA processing defects induce replication stress and Chk2-dependent
disruption of piRNA transcription.
The EMBO journal : 3009-27 : DOI : 10.15252/embj.201591006
Nicolas Christophorou, Thomas Rubin, Isabelle Bonnet, Tristan Piolot, Marion Arnaud, Jean-René
Huynh (2015 Oct 13)
Microtubule-driven nuclear rotations promote meiotic chromosome dynamics
Nature cell biology : 1388-400 : DOI : 10.1038/ncb3249
Neuza Reis Matias, Juliette Mathieu, Jean-René Huynh (2015 Feb 3)
Abscission is regulated by the ESCRT-III protein shrub in Drosophila germline
stem cells.
PLoS genetics : e1004653 : DOI : 10.1371/journal.pgen.1004653
Year of publication 2013
Nicolas Christophorou, Thomas Rubin, Jean-René Huynh (2013 Dec 19)
Synaptonemal complex components promote centromere pairing in pre-meiotic
germ cells.
PLoS genetics : e1004012 : DOI : 10.1371/journal.pgen.1004012
INSTITUT CURIE, 20 rue d’Ulm, 75248 Paris Cedex 05, France | 2
Germ Cell Development
U934/UMR3215 – Genetics and Developmental Biology
Juliette Mathieu, Clothilde Cauvin, Clara Moch, Sarah J Radford, Paula Sampaio, Carolina N
Perdigoto, François Schweisguth, Allison J Bardin, Claudio E Sunkel, Kim McKim, Arnaud Echard,
Jean-René Huynh (2013 Aug 12)
Aurora B and cyclin B have opposite effects on the timing of cytokinesis
abscission in Drosophila germ cells and in vertebrate somatic cells.
Developmental cell : 250-65 : DOI : 10.1016/j.devcel.2013.07.005
Year of publication 2008
Pierre Fichelson, Clara Moch, Kenzo Ivanovitch, Charlotte Martin, Clara M Sidor, Jean-Antoine
Lepesant, Yohanns Bellaiche, Jean-René Huynh (2008 Nov 14)
Live-imaging of single stem cells within their niche reveals that a U3snoRNP
component segregates asymmetrically and is required for self-renewal in
Drosophila.
Nature cell biology : 685-93 : DOI : 10.1038/ncb1874
INSTITUT CURIE, 20 rue d’Ulm, 75248 Paris Cedex 05, France | 3