photoreceptor cell & axon
RP3 neuron & synapse
dock3 cknK.Δ324-331 double homozygotes exhibit delayed 'immature' ISNb axons in 65% of hemisegments. Motor axons in the affected nerves are loosely organised with multiple projections and resemble wild-type axons at earlier stages. Furthermore, the ISNd branch is frequently absent or reduced in size. Examination of the ISNb/d choice point reveals defects in ISNb/d branch segregation. The lateral two longitudinal Fas2-positive fascicles are poorly fasciculated and discontinuous in these double mutants.
When enaGC5/enaGC1 and homozygous dock3 are combined only a mild additive effect is see on the longitudinal exon guidance phenotype. Heterozygous dock3 enhances the longitudinal axon ectopic midline crossing defect seen in transheterozygous sli1, robo5 mutants. An average of 5.7 defects are seen per animal. 52% of segments (calculated as number of defects/segments) show defects.