1. Jean-Maurice Dura Institut de Génétique Humaine
M1 Neurosciences Neurobiologie du Développement HMBS116
année 2017/2018
Jeudi 27 Septembre 9h45 SC 25.05
Jeudi 18 Octobre 9h45 SC 20.02
Jeudi 25 Octobre 9h45 SC 20.02
Jeudi 8 Novembre 9h45 SC 25.01
Jeudi 15 Novembre 8h SC 25.01
Jeudi 22 Novembre 8h SC 16.01
Neuronal remodeling:
Luo and Leary Annu Rev Neurosci 2005
Schuldiner and Yaron Cell Mol Life Sci 2015
Boulanger and Dura Biochim Biopys Acta 2015
Yaniv and Schuldiner WIREs Dev Biol 2016

2. Two variations of axon pruning
Neuronal guidance CSHPiB 320.1

3. vertebrate neuromuscular junction (NMJ).
Small-scale axon elimination exemplified by synapse elimination at a “generic”
vertebrate neuromuscular junction (NMJ).
MN : motor neuron MF : muscle fiber
Luo ARN 2005

4. Small-scale axon elimination to develop eye-specific patterned connections.
RGC : retinal ganglion cells - dLGN : dorsal lateral geniculate nucleus – V1 : visual area
Luo ARN 2005

5. DCN : dorsal column nuclei ic : internal capsule IO : inferior olive
Large-scale axon elimination to develop area-specific subcortical projections of layer 5 neurons of the neocortex
BP : basillar pons
cp : cerebral peduncle
DCN : dorsal column nuclei
ic : internal capsule
IO : inferior olive
Mes : mesencephalon
pd : pyramidal decussation
pt : pyramidal tract
SC : superior colliculus
Luo ARN 2005

6. The mushroom bodies (MBs) in the adult Drosophila brain
Rein et al., 2002 Current Biology

7. NHL mid-3rd instar APF

8. immature neural circuit into a mature one.
Vanessa
Vanessa
Developmental axon pruning is a general mechanism required to transform an
immature neural circuit into a mature one.
During Drosophila metamorphosis, larval-specific dendrites and axons of early g
neurons of the mushroom bodies are pruned and replaced by adult-specific
processes
Lee et al., Development 1999

9. Clonal analysis
-/-
-/-
-/-
+/-
+/+
+/+

13. in yeast
FLP recombinase (FLPase)
FRT: FLPase Recombination Targets
transgenesis in Drosophila
clonal expression

14. Mutant clones in a mosaic organism by the classical technique are unmarked
Lee Neuron 1999

16. Repressible marker = GFP under GAL4 control
Marking mutant clones in a mosaic organism by the MARCM technique
Mitotic recombination
After DNA replication
Two distinct
mosaic progeny
Parental cell
Expressed
marker
Repressor
protein
Repressed
marker x x x x x
FRT x x x
Centro
mere
Repressor
MARCM : Mosaic Analysis with a Repressible Cell Marker
Repressible marker = GFP under GAL4 control
Repressor = GAL80
x = lethal mutation
after Lee Neuron 1999

17. Schematic drawing shows the essence of the MARCM system
Schematic drawing shows the essence of the MARCM system. Mitotic recombination
between two FRT sites (triangles) results in loss of the repressor transgene (tubP-GAL80) in
one of the daughter cells, and hence GAL4-dependent expression of the marker transgene
(UAS-mGFP).
Lee Dev 1999

18. A single photoreceptor can be traced from cell body in eye disc (arrow in left panel) to the end of the extending axon in the optic lobe (arrow in right panel)
e: eye disc b: brain
Lee Neuron 1999

19. A multi-cellular neuroblast clone Single-cell / two cell clones
FLP Nb
Nb : neuroblast G : GMC (ganglion mother cell) N : neuron
Single-cell / two cell clones
FLP
Lee et al., Development 1999

20. A schematic representation of axon pruning in MB g neurons
Yu and Schuldiner COiN 2014

21. in NHL and examined 12, 18 and 24 hours APF (see dia 7)
Axon reorganization of  neurons during metamorphosis. Clones were generated
in NHL and examined 12, 18 and 24 hours APF (see dia 7)
+/+
+/+
Lee et al., Development 1999

22. +/+
Lee et al., Neuron 2000
+/+

23. and neuroblast clones also
Summary of the genetic crosses for the MARCM-based genetic screen
Lee et al., Neuron 2000

24. -/-
+/+
+/-
+/+
Identification of the l(X)48 mutant defective in the pruning of larval-specific
axons and dendrites
Lee et al., Neuron 2000

25. l(X)48 is a mutant allele of the nuclear receptor ultra spiracle (usp)
-/-
+/-
Lee et al., Neuron 2000

26. usp4 and usp3 two previously identified usp alleles.
l(X)48 = usp5
usp4 and usp3 two previously identified usp alleles.
All three alleles result in changes of invariant arginines that contact
phosphates in target DNA
Lee et al., Neuron 2000

27. The ECR-USP heterodimer binds ecdysone (E) and an EcRE in the DNA,
activating a downstream promoter (arrow)
Ecdysone pics during development

28. EcR-B1 is expressed only in the neurons.
EcR-B1 is neither expressed in the ’’nor in the  neurons.
How EcR-B1 is so precisely regulated?
Lee et al., Neuron 2000

29. -/-
+/-
-/-
+/-
+ UAS-babo-a
Zheng et al., Cell 2003

30. -/-
+/-
Zheng et al., Cell 2003

31. myoglanin
Zheng et al., Cell 2003

32. +/+
+/+
-/-
+/-

33. The nuclear receptors FTZ-F1 and HR39
ADN
HR39
ADN
LIGAND
LIGAND DN
22%
63 %
FTZ-F1

34. The nuclear receptors FTZ-F1 and HR39
Both proteins have the same target sequences in vitro.
Competition between the two receptors for binding to a common DNA element (Ohno et al., MCB 94).
Antagonist role of the two proteins HR39 et FTZ-F1 in vivo?

35. +/+
+/+
+/+
+/+
+ UAS-Hr39
Boulanger et al., Nature Neuroscience 2011

36. Awasaki and Lee after Boulanger at al., Nature Neuroscience 2011