Rows show examples representing the main phenotypic categories recovered from the central (RP2) neuron dendrite misexpression screen

Left and centre columns: confocal images (maximal Z-projections) of RP2 neurons at 25–31 hours AEL, visualised with . Control RP2 neuron with brackets indicating the dendritic tree. Control RP2 neuron in the context of a set of axon tracts visualised by anti-FasciclinII staining (magenta), with arrowheads pointing from top to bottom to the lateral, intermediate and medial FasciclinII tracts and the midline indicated by a dotted line. Dendrites between the lateral and central intermediate Fasciclin II fascicle are defined as 'lateral'; dendrites located between the central intermediate fascicle and the midline as 'medial'; the same applies to (o,p). Same neuron as in (b) but with sectors of its dendritic tree pseudo-coloured to highlight branches targeted to anterior lateral (magenta), anterior medial (yellow) and posterior lateral (cyan) regions. Anterior is left and the ventral midline is down. Experimental cells: misexpression lines are indicated in the bottom right-hand corner of each panel. Right column: quantifications of the dendritic phenotypes shown in the left and central columns. As illustrated in (f), both dendritic tree length and number of branching events are reduced in the 'Growth' and 'Branching' categories. 'Branching' phenotypes have trees with an anterior-posterior extent comparable to controls (Additional file ) but have an altered pattern of branching: fewer branching events and more segments that are longer (>5 μm). *< 0.01, **< 0.005, -test, N = 5. Error bars indicate the standard error. Arrows in (b,o,p) point to medial branches present in controls (b) and absent/reduced in experiments (o,p). Black asterisks in (e,p) indicate the cell body of the contralateral RP2 neuron. Scale bar: 10 μm.<p><b>Copyright information:</b></p><p>Taken from "Identification of genes influencing dendrite morphogenesis in developing peripheral sensory and central motor neurons"</p><p>http://www.neuraldevelopment.com/content/3/1/16</p><p>Neural Development 2008;3():16-16.</p><p>Published online 10 Jul 2008</p><p>PMCID:PMC2503983.</p><p></p

Proportional Venn diagrams to describe the degree of overlap among genes that emerged from both screens

The total is shown at top left, and then broken down by the predicted site of gene product activity.<p><b>Copyright information:</b></p><p>Taken from "Identification of genes influencing dendrite morphogenesis in developing peripheral sensory and central motor neurons"</p><p>http://www.neuraldevelopment.com/content/3/1/16</p><p>Neural Development 2008;3():16-16.</p><p>Published online 10 Jul 2008</p><p>PMCID:PMC2503983.</p><p></p

RP2 neurons at 25–31 hours AEL and visualised with in the context of FascicilinII positive axon bundles (magenta) demarcating the medial and lateral neuropile (maximal Z-projections of confocal image stacks)

Control. Misexpression of (activated ) leads to a lack of dendritic innervation of the medial neuropile (normally located anterior to the axon (arrowhead in (a)) and a concomitant expansion of dendrites in the lateral neuropile posterior to the axon (arrowhead in (b))). Dendritic extent anterior or posterior to the axon is indicated by brackets. Quantification of anterior, posterior and total (combined) maximal dendritic extent for controls (green, N = 10) and expression RP2 neurons (magenta, N = 8). The significance of pair-wise comparisons using Student's -test is indicated. Anterior is left and the ventral midline is down. Scale bar: 20 μm.<p><b>Copyright information:</b></p><p>Taken from "Identification of genes influencing dendrite morphogenesis in developing peripheral sensory and central motor neurons"</p><p>http://www.neuraldevelopment.com/content/3/1/16</p><p>Neural Development 2008;3():16-16.</p><p>Published online 10 Jul 2008</p><p>PMCID:PMC2503983.</p><p></p

Three-dimensional reconstructions from confocal image stacks of RP2 neurons at 25–31 hours AEL and visualised with generated with AMIRA software

Control. Misexpression of causes aberrant dendritic targeting to the posterior. Brackets in (a) indicate the dendritic tree. Dendrograms derived from the reconstructions with branch points highlighted in magenta and the cell body and axon offset from the dendritic tree by green. Quantification of the dendritic architectures for controls (green, N = 4) and expressing RP2 neurons (magenta, N = 4). The significance of pair-wise comparisons using Student's -test is indicated. Error bars indicate the standard error. Anterior is left and the ventral midline is down. Scale bar: 10 μm.<p><b>Copyright information:</b></p><p>Taken from "Identification of genes influencing dendrite morphogenesis in developing peripheral sensory and central motor neurons"</p><p>http://www.neuraldevelopment.com/content/3/1/16</p><p>Neural Development 2008;3():16-16.</p><p>Published online 10 Jul 2008</p><p>PMCID:PMC2503983.</p><p></p

Control and experiments showing confocal images (maximal Z-projections) of RP2 neurons at 25–31 hours AEL, visualised with (green) in the context of a set of axon tracts visualised by anti-FasciclinII staining (magenta)

Dendrites between the lateral and central intermediate Fasciclin II fascicle are defined as 'lateral'; dendrites located between the central intermediate fascicle and the midline as 'medial'. Misexpression lines are indicated in the bottom left hand corner of each panel. Misexpression of () leads to aberrant midline crossing of dendritic branches (arrowhead), though no apparent increase of dendrites targeted towards the midline between the intermediate and medial FascilinII tracts. The high variability in phenotype is partly due to the varying lengths the dendritic tree mis-routed across the ventral midline. Misexpression of () causes increased targeting of dendrites into the medial neuropile (arrowhead). Black asterisk indicates the cell body of the contralateral RP2 neuron. Ventral (d) and lateral (d') views of stage 13 embryos driving expression of GSd433 with and stained by in hybridisation using an anti-sense probe against . The staining shows the segmentally repeated stripes characteristic for . The reaction had to be terminated before the endogenous expression pattern appeared (see Additional file ) due the high levels of expression. Misexpression of by GSd433 (e) or (f) leads to a reduction to near absence () of branches innervating the medial neuropile (arrowheads), and some dendritic branches positioned aberrantly lateral of the lateral Fasciclin II axon tract (arrows). Quantification showing ratios of medial/lateral dendrites; *= 0.04, **< 0.001, -test, N = 5; error bars indicate the standard error. Anterior is left. Scale bars: (a-c,e,f) = 10 μm; (d,d') = 140 μm.<p><b>Copyright information:</b></p><p>Taken from "Identification of genes influencing dendrite morphogenesis in developing peripheral sensory and central motor neurons"</p><p>http://www.neuraldevelopment.com/content/3/1/16</p><p>Neural Development 2008;3():16-16.</p><p>Published online 10 Jul 2008</p><p>PMCID:PMC2503983.</p><p></p