Grillenzoni, Nicola Vaux, Véronique de Meuwly, Jocelyne Vuichard, Séverine Jarman, Andrew Holohan, Eimear Gendre, Nanaë Stocker, Reinhard F. 2007-01-27 In this paper, we address the role of proneural genes in the formation of the dorsal organ in the <i>Drosophila</i> larva. This organ is an intricate compound comprising the multineuronal dome—the exclusive larval olfactory organ—and a number of mostly gustatory sensilla. We first determine the numbers of neurons and of the different types of accessory cells in the dorsal organ. From these data, we conclude that the dorsal organ derives from 14 sensory organ precursor cells. Seven of them appear to give rise to the dome, which therefore may be composed of seven fused sensilla, whereas the other precursors produce the remaining sensilla of the dorsal organ. By a loss-of-function approach, we then analyze the role of <i>atonal</i>, <i>amos</i>, and the <i>achaete-scute</i> complex (<i>AS- C</i>), which in the adult are the exclusive proneural genes required for chemosensory organ specification. We show that <i>atonal</i> and <i>amos</i> are necessary and sufficient in a complementary way for four and three of the sensory organ precursors of the dome, respectively. <i>AS- C</i>, on the other hand, is implicated in specifying the non-olfactory sensilla, partially in cooperation with <i>atonal</i> and/or <i>amos</i>. Similar links for these proneural genes with olfactory and gustatory function have been established in the adult fly. However, such conserved gene function is not trivial, given that adult and larval chemosensory organs are anatomically very different and that the development of adult olfactory sensilla involves cell recruitment, which is unlikely to play a role in dome formation. application/pdf https://folia.unifr.ch/global/documents/300283 https://folia.unifr.ch/documents/300283/files/427_2007_Article_135.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1007/s00427-007-0135-6 info:eu-repo/semantics/openAccess License undefined Development Genes and Evolution. - 2007, vol. 217, no. 3, p. 209-219 proneural genes dorsal organ olfactory receptor neurons embryogenesis Drosophila info:eu-repo/classification/udc/57 Role of proneural genes in the formation of the larval olfactory organ of Drosophila http://purl.org/coar/resource_type/c_6501