TY - JOUR A1 - He, Bicheng A1 - Büscher, Marita A1 - Farnworth, Max Stephen A1 - Strobl, Frederic A1 - Stelzer, Ernst H. K. A1 - Koniszewski, Nikolaus Dieter Bernhard A1 - Mühlen, Dominik A1 - Bucher, Gregor T1 - An ancestral apical brain region contributes to the central complex under the control of foxQ2 in the beetle Tribolium T2 - eLife N2 - The genetic control of anterior brain development is highly conserved throughout animals. For instance, a conserved anterior gene regulatory network specifies the ancestral neuroendocrine center of animals and the apical organ of marine organisms. However, its contribution to the brain in non-marine animals has remained elusive. Here, we study the function of the Tc-foxQ2 forkhead transcription factor, a key regulator of the anterior gene regulatory network of insects. We characterized four distinct types of Tc-foxQ2 positive neural progenitor cells based on differential co-expression with Tc-six3/optix, Tc-six4, Tc-chx/vsx, Tc-nkx2.1/scro, Tcey, Tc-rx and Tc-fez1. An enhancer trap line built by genome editing marked Tc-foxQ2 positive neurons, which projected through the primary brain commissure and later through a subset of commissural fascicles. Eventually, they contributed to the central complex. Strikingly, in Tc-foxQ2 RNAi knock-down embryos the primary brain commissure did not split and subsequent development of midline brain structures stalled. Our work establishes foxQ2 as a key regulator of brain midline structures, which distinguish the protocerebrum from segmental ganglia. Unexpectedly, our data suggest that the central complex evolved by integrating neural cells from an ancestral anterior neuroendocrine center. Y1 - 2019 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/53125 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-531258 N1 - (c) Copyright He et al. This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited. VL - 8 IS - e49065 SP - 1 EP - 29 ER -