DA dendrite formation

Dendrite guidance

Clock model: axonal and dendritic growth are internally regulated, depending on how to respond to guidance molecules

WT Robo3 over- expression in TTMn Robo3 over- expression in both GF & TTMn GF, giant fiber interneuron TTMn: tergotrochantral motor neuron

Neuropil model: same guidance molecules for attracting (or including) axon and dendrite together for synapse TRENDS in Neurosciences Vol.27 No.4 April 2004

achaete scute atonal amos Proneural genes Sensory organs + associated MD neurons solo-MD neurons

ESMD / mono-ESMD / poly-ES CHMD / CH solo-MD ASC ato amos Brewster and Bodmer, 1995 ES CH MD amos

Control of dendrite development Luo. et al. Trends Neuroscience (2003)

DA Dendrite formation

Constitutive active CDC42 induce supernumerary primary dendrites that fail to extend dorsally and grow secondary dendrites WT CDC42 pros mutations causes routing defect

Lateral branch defects: (A) WT, (B) reduced, (C) fail to extend, (E, F) over shrinking Increased density

Sequotia ( 水杉 ), Zn finger protein

No repulsion in dorsal group No invasion into ablated region in dorsal region in third instar

Competition between two dorsal groups of contralateral dorsal groups

Dorsal dendrite overextension in flamingo mutants

Class I Class II

Class III

Development (2002) Grueber et al Tiling of dendrites within the same class of DA neurons

Cell (2003) Grueber et al

Dendrites of different classes overlap extensively Class III and IVClass I and IV

Class IV tiling

Differential Cut levels in four types of DA neurons

cut mutant phenotypes in class III

Class II Class I

Class II

Class IV No effect on class III

Dendrites over-branching and over-lapping phenotypes

Defect in like-dendrite avoidance response WT fry

Heteroneuronal tiling defect Trc kinase Rac Fry branching tiling