A Gain-of-Function Screen for Genes That Affect the Development of the Drosophila Adult External Sensory Organ

TLDR

The Drosophila adult external sensory organ develops from a single precursor through multiple asymmetric divisions. The study aimed to identify molecules affecting sensory organ development via a tissue‑specific gain‑of‑function screen. A screen of 2,293 P‑element lines identified 105 lines at 78 loci that caused misexpression phenotypes altering sensory organ number, fate, or morphology, which were grouped into three classes. The screen revealed three classes of phenotypes—loss of organs, increased organ numbers, and cell fate changes—highlighting both known peripheral nervous system genes and many novel candidates.

Abstract

Abstract The Drosophila adult external sensory organ, comprising a neuron and its support cells, is derived from a single precursor cell via several asymmetric cell divisions. To identify molecules involved in sensory organ development, we conducted a tissue-specific gain-of-function screen. We screened 2293 independent P-element lines established by P. Rørth and identified 105 lines, carrying insertions at 78 distinct loci, that produced misexpression phenotypes with changes in number, fate, or morphology of cells of the adult external sensory organ. On the basis of the gain-of-function phenotypes of both internal and external support cells, we subdivided the candidate lines into three classes. The first class (52 lines, 40 loci) exhibits partial or complete loss of adult external sensory organs. The second class (38 lines, 28 loci) is associated with increased numbers of entire adult external sensory organs or subsets of sensory organ cells. The third class (15 lines, 10 loci) results in potential cell fate transformations. Genetic and molecular characterization of these candidate lines reveals that some loci identified in this screen correspond to genes known to function in the formation of the peripheral nervous system, such as big brain, extra macrochaetae, and numb. Also emerging from the screen are a large group of previously uncharacterized genes and several known genes that have not yet been implicated in the development of the peripheral nervous system.