Development of Morphological Diversity of Dendrites in Drosophila by the BTB-Zinc Finger Protein Abrupt

Morphological diversity of dendrites contributes to specialized functions of individual neurons. In the present study, we examined the molecular basis that generates distinct morphological classes of Drosophila dendritic arborization (da) neurons. da neurons are classified into classes I to IV in order of increasing territory size and/or branching complexity. We found that Abrupt (Ab), a BTB-zinc finger protein, is expressed selectively in class I cells. Misexpression of ab in neurons of other classes directed them to take the appearance of cells with smaller and/or less elaborated arbors. Loss of ab functions in class I neurons resulted in malformation of their typical comb-like arbor patterns and generation of supernumerary branch terminals. Together with the results of monitoring dendritic dynamics of ab-misexpressing cells or ab mutant ones, all of the data suggested that Ab endows characteristics of dendritic morphogenesis of the class I neurons.