Spatio-temporal relays control layer identity of direction-selective neuron subtypes in Drosophila
journal contributionposted on 2020-06-25, 15:16 authored by Holger Apitz, Iris Salecker
Visual motion detection in sighted animals is essential to guide behavioral actions ensuring their survival. In Drosophila, motion direction is first detected by T4/T5 neurons. Their axons innervate one of the four lobula plate layers. How T4/T5 neurons with layer-specific representation of motion-direction preferences are specified during development is unknown. We show that diffusible Wingless (Wg) between adjacent neuroepithelia induces its own expression to form secondary signaling centers. These activate Decapentaplegic (Dpp) signaling in adjacent lateral tertiary neuroepithelial domains dedicated to producing layer 3/4-specific T4/T5 neurons. T4/T5 neurons derived from the core domain devoid of Dpp signaling adopt the default layer 1/2 fate. Dpp signaling induces the expression of the T-box transcription factor Optomotor-blind (Omb), serving as a relay to postmitotic neurons. Omb-mediated repression of Dachshund transforms layer 1/2- into layer 3/4-specific neurons. Hence, spatio-temporal relay mechanisms, bridging the distances between neuroepithelial domains and their postmitotic progeny, implement T4/T5 neuron-subtype identity.
AllelesAnimalsAxonsDrosophila ProteinsDrosophila melanogasterFemaleGene Expression Regulation, DevelopmentalMaleMotion PerceptionNerve Tissue ProteinsNeuronsNuclear ProteinsProtein DomainsRNA InterferenceSignal TransductionT-Box Domain ProteinsVision, OcularWings, AnimalWnt1 ProteinSalecker FC001151