Expression of ab^{Scer\UAS.L.cSa} in all da neurons, driven by Scer\GAL4^109(2)80 and Scer\GAL4^IG1-2 together, causes an alteration of overall patterns of dendritic arbors in larvae. These larvae show large dendrite-free zones around segmental boundaries and dorsal midlines, which lie midway between ipsilateral and contralateral dorsal clusters, while control larvae show dendritic trees over all of the body wall. The total number and the stereotypic arrangement of da neurons is not changed in the ab^{Scer\UAS.L.cSa}-expressing larvae, suggesting that class II-IV dendritic trees are reduced in size. This downsizing effect occurs with complete penetrance.

Single-cell analysis on ddaC neurons that express ab^{Scer\UAS.L.cSa} under the control of Scer\GAL4^109(2)80 and Scer\GAL4^IG1-2 show a reduced dendritic field and exhibit a visibly less complex morphology compared to wild type. The branch terminals of the mutant ddaC do not reach far enough to meet those of adjacent cells and higer-order fine branches are not elaborated. Time-lapse analysis shows that ab^{Scer\UAS.L.cSa}-expressing ddaC neurons almost halt branching and stabilize their overall dendritic shape by midlarval stages.

Expression of ab^{Scer\UAS.L.cSa} under the control of Scer\GAL4^109(2)80 and Scer\GAL4^IG1-2 results in a morphological change in ddaA neurons as they do not show the characteristic short, straight protrusions that wild-type ddaA neurons exhibit. The ab^{Scer\UAS.L.cSa}-expressing ddA neurons also show a lower terminal number than controls and a significant decrease in the field size. The size of ddaB dendritic fields is also reduced in this genotype but the number of ddaB branch terminals is not altered. The dendritic field size and number of branch terminals is not affected in either ddaD or ddaE neurons.

Scer\GAL4²²¹/ab^UAS.L.cSa is a suppressor of abnormal neuroanatomy | larval stage phenotype of Scer\GAL4²²¹, kn^{UAS.cHa.Tag:HA}