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DCN – their axonal behaviour. LabRetreat 04.06.2007. Overview. Axon Extension & Retraction Experiments: Number of Dorsal Cluster Neurons Axons in ME Neuron vs. Axon positioning Computation: Wildtype/Mutation Overview Chinmo Axon Branching Experiments Rab5 DN Rab7 DN dORK Shi DN.
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DCN – their axonal behaviour LabRetreat 04.06.2007
Overview • Axon Extension & Retraction • Experiments: • Number of Dorsal Cluster Neurons • Axons in ME • Neuron vs. Axon positioning • Computation: • Wildtype/Mutation Overview • Chinmo • Axon Branching • Experiments • Rab5 DN • Rab7 DN • dORK • Shi DN
Number of Dorsal Cluster Neurons • Genotype: w1118/yw;UAS-lacZ.NZ(20b);atoGal-14a & w1118/yw;;UAS-lacZ.NZ(J312)/atoGal-14a • Condition: room temperature • Sorting: • Age: 2, 7, 14, 28, 42 days • Gender: ♀ and ♂ • Staining: β-gal
Number of Dorsal Cluster Neurons Genotype: atoGal4-14a X UAS::nlacZ Staining:α-βgal Gender: male Age: 2 days old Location: right side Neurons: 56
Number of Dorsal Cluster Neurons → There is no statistical significant difference between the two Dorsal Cluster of each brain regarding age and gender.
Graphical Results DCNs Mean + SD ** indicates statistical significant differences, (not all stat. signif. differences are shown)
Axons in the Medulla • Genotype: w/+;;UAS-lacZ,atoGal-14a/+ • Condition: room temperature • Sorting: • Age: 2 days • Gender: ♀ and ♂ • Staining: β-gal
Axons in the Medulla Genotype: atoGal4-14a X UAS::lacZ Staining:α-βgal 1 2 3 4 5 6 7 8 9 Gender: male Age: 2 days old Location: right side Axons: 12 10 11 12
I II III IV V VI VII VIII IX X XI XII Axons in Medulla
Neuron vs. Axon Position • Genotype: w/yw,hsFlp;+/(Sp v Cyo); UAS-lacZ,ato-Gal4-14a/UAS>CD2,y>mCD8-Gfp • Condition: 28°C • Age: 2 days • Staining: β-gal (mouse), gfp (rabbit)
a1 a2 a3 a4 a5 a1 a2 a3 a4 a5
a1 a2 a3 a4 a5
Computational Model • Assumptions • Number of Neurons: 56 • Number of Axons in Medulla: 12 • Algorithm • GIN • Neighbourhood Competition + Timing
Wnt FGF Fz FGFR DSH RAC P-JNK P-JNK EXTENSIONRETRACTION Lobula Medulla Gene Interaction Network Srahna et al. 2006
Computational Model - Overview Number Of DCNs Wnt based on Connectivity Of DCNs FGF GIN uses
GIN – Implemented Logic before Lobula Lobula Medulla Time wnt5 & wnt2 & fz & fz2 Signals: None fgf & fgfr true false false true false Rac: false true true false true JNK:
Neighbourhood Competition • Neighbourhood consists of • 8 + • the current neuron
Neighbourhood Competition • Logic for competition • Choose one neuron ni randomly (it must have permission from GIN) • If (ni-4+ni-3+ni-2+ni-1+ ni+ni+1+ni+2+ni+3+ni+4 >=2) • Then ni→ Lobula = 0 • Else ni→ Medulla = 1 • Repeat these two steps until there is a stable pattern or a time dependent pattern has been found.
wnt fgf Computational Model Lobula Medulla 1 2 3 4 5 6 7 8 9 10 11 12
Computational Model – Wnt Signal Mean + SD
Computational Model – FGF Signal Mean + SD
Chinmo Hypothesis: Only those axons are in the Medulla which lacks Chinmo !
Chinmo • Assumptions: • 56 Neurons • 12 Axons remain in the Medulla • There is a neighbourhood communication • GIN extended by Chinmo
Chinmo – A teamplayer of GIN? Wnt FGF Fz FGFR DSH Chinmo RAC P-JNK P-JNK EXTENSIONRETRACTION Srahna et al. 2006 Lobula Medulla
GIN + Chinmo – Implemented Logic before Lobula Lobula Medulla Time wnt5 & wnt2 & fz & fz2 Signals: None fgf & fgfr & Chinmo true false false true false Rac: false true true false true JNK:
Chinmo • Some thoughts: 56! 56! = 5,583833073 * 1011= 558.383.307.300 = 12! * 44! 12! * (56-12)! • Model: • 40.000 different settings (<< 1% ) • 1.019 settings had 12 Axons in the Medulla • 1.019 are not unique ! • 24 fits the spatial structure of „12 Axons in ME“ • BUT: Since these 24 settings are not unique, it might be that there is no competition and therefore CHINMO+GIN decide about axonal fate.
A18♀ X Rab5DN♂w;;UAS-lacZ,atoGal4-14a/UAS-Drab5S43N Rab5DN ♂ Wildtype
Clathrin♀ X A18♂w/w1118chc4;;UAS-lacZ,atoGal4-14a ♀ FM7aGFP;;UAS-lacZ,atoGal4-14a ♂ Wildtype Clathrin ♀ Clathrin ♂
A18♀ X Rab7DN♂w;UAS-Drab7;UAS-lacZ,atoGal4-14a Rab7DN ♀ Rab7DN ♂ Wildtype
A18♀ X dORK♂w;;UAS-lacZ,atoGal4-14a/UAS dORKΔc1 dORK ♀ dORK ♂ Wildtype
A18♀ X ShiDN♂w/yw,UAS-ShiK44a(4-1);UAS-ShiK44a(3-7);UAS-lacZ,atoGal4-14a ♀w;UAS-ShiK44a(3-7);UAS-lacZ,atoGal4-14a ♂ ShiDN ♀ ShiDN ♂ Wildtype