Offre de stage de Master / Master Internship offer

MASTERBIOSCIENCES
ECOLE NORMALE SUPERIEURE DE LYON
Offre de stage de Master / Master Internship offer
Tuteur du stage et Laboratoire d’accueil / Internship supervisor and Host laboratory:
Laboratory: Reproduction et Développement des plantes http://www.ens-lyon.fr/RDP
Supervision: Mathilde Dumond (PhD student) and Arezki Boudaoud
[email protected], [email protected]
Titre du projet de recherche / Research project title:
Reproducibility of organ shapes: Analysis of a new Arabidopsis mutant with decreased variability
of sepal shape
Description du projet / Project description:
In all living organisms, size is a tightlycontrolled feature. Bacterial cells, insect wings,
human hands, plant sepals, all have a specific
size which is precisely controlled for the organ
to be effective – how could a fly make use of
wings of different lengths, how could a growing
flower be protected during its growth if the
sepals did not have the right size.
Many studies tackled the question of the control
of organ size, finding evidence of the influence
of hormones and growing factors – some
finding mutants where wings/sepals were bigger
or smaller on average– leaving the variability
within an individual relatively unexplored.
Here we focus on the variability of size of
sepals in Arabidopsis thaliana. Each plant
having 50 to 60 flowers, it makes it practical to
measure variability, reducing as well sensitivity
to the environment. In A. thaliana the variability
of sepal area is around 8%.
Is this variability regulated – and how? Are
there genes specifically controlling size
variability?
We performed a screen to find mutations enhancing or reducing the variability of sepal size within
the plant. While several mutants exhibited increased variability, one mutant instead displayed a
reduced variability, when compared to the control.
Two directions can be possible for the internship depending on the intern's affinities.
- The final size of an organ is the integration of all the events happening during the growth of the
organ. To understand how the mutant can achieve organs less variable than the control, the intern
will image the growth of mutant and wild type sepal using a confocal microscope, analyze the
images using state-of-the-art softwares to compute growth rates and other indicators of growth; and
compare the overall growth of the mutant and of the wild type.
- We may hypothesize that a basal level of variability in the wild type may allow adaptation to
MASTERBIOSCIENCES
ECOLE NORMALE SUPERIEURE DE LYON
variable environmental cues. To test this hypothesis, the intern will grow wild type and mutant
plants in different and more or less variable environments, and measure the sepal shape variability
in these different conditions.
Publications du laboratoire (5 max) / Lab publications (5 max):
Uyttewaal M,Burian A, Alim K, Landrein B, Borowska-Wykręt D, Dedieu A, Peaucelle A, Ludynia
M, Traas J, Boudaoud A, Kwiatkowska D, Hamant O (2012) A katanin-dependent microtubule
response to mechanical stress enhances growth gradients between neighboring cells in Arabidopsis.
Cell 149 (2): 439-451.
L. Hong*, M. Dumond*, S. Tsugawa*, A. Sapala, A.-L. Routier-Kierzkowska, Y. Zhou, C. Chen, A.
Kiss, M. Zhu, O. Hamant, R. S. Smith, T. Komatsuzaki, C.-B. Li, A. Boudaoud & A. H. K. Roeder.
Variable cell growth yields reproducible organ development through spatiotemporal averaging. Dev.
Cell 38, 15-32.
de Reuille PB, Routier-Kierzkowska AL, Kierzkowski D, Bassel GW, SchüpbachT, Tauriello G,
Bajpai N, Strauss S, Weber A, Kiss A, Burian A, Hofhuis H, Sapala A, Lipowczan M, Heimlicher
M, Robinson S, Bayer E, Basler K, Koumoutsakos P, Roeder A, Aegerter-Wilmsen T, Nakayama N,
Tsiantis M, Hay A, Kwiatkowska D, Xenarios I, Kuhlemeier C, Smith R. MorphoGraphX: A
platform for quantifying morphogenesis in 4D. Elife, 2015;4:e05864.
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ECOLE NORMALE SUPERIEURE DE LYON