RT Journal Article SR Electronic T1 The architectural balance of the Ventral Nerve Cord depends on the level of JNK signaling activity JF bioRxiv FD Cold Spring Harbor Laboratory SP 092486 DO 10.1101/092486 A1 Katerina Karkali A1 George Panayotou A1 Timothy E. Saunders A1 Enrique Martín-Blanco YR 2016 UL http://biorxiv.org/content/early/2016/12/08/092486.abstract AB The segmented nervous system of bilaterians is organized in structural and functional modules. Modules share across species a robust structural stability. How this robustness is acquired during development is currently unknown. Here, we investigate the sequence of events involved in the establishment of the architectural balance of the nervous system. We demonstrate that a unique robustness pattern is common to the arthropods nervous system plan. This pattern depends on the fine control of the JNK signaling in a subset of early-specified pioneer neurons. JNK activity affects the level of expression of cell adhesion molecules (Fas 2), in part through the modulation of the transcription factor zfh1. A deficit in Fas 2 affects the fasciculation of the axons of primary neurons, leading to secondary bundling defects that result in a general reduction in spatial correlations. Failure to fasciculate affects both architectural robustness and tensional balance, ultimately impeding nervous system condensation.