RT Journal Article SR Electronic T1 Tissue interactions govern pattern formation in the posterior lateral line of medaka JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.03.26.009969 DO 10.1101/2020.03.26.009969 A1 Ali Seleit A1 Karen Gross A1 Jasmin Onistschenko A1 Oi Pui Hoang A1 Jonas Theelke A1 Lázaro Centanin YR 2020 UL http://biorxiv.org/content/early/2020/03/29/2020.03.26.009969.abstract AB Vertebrate organs are arranged in a stereotypic, species-specific position along the animal body plan. Substantial morphological variation exists between related species, especially so in the vastly diversified teleost clade. It is still unclear how tissues, organs and systems can accommodate such diverse scaffolds. Here, we use the sequential formation of neuromasts in the posterior lateral line (pLL) system of medaka fish to address tissue-interactions defining a pattern. We show that the pLL pattern is established independently of its neuronal wiring, and demonstrate that the neuromast precursors that constitute the pLL behave as autonomous units during pattern construction. We uncover the necessity of epithelial integrity for correct pLL patterning by disrupting keratin 15 (krt15) and creating epithelial lesions that lead to novel neuromast positioning. By using krt15/wt chimeras, we determined that the new pLL pattern depends exclusively on the mutant epithelium, which instructs wt neuromast to locate ectopically. Inducing epithelial lesions by 2-photon laser ablation during pLL morphogenesis phenocopies krt15 genetic mutants and reveals that epithelial integrity defines the final position of the embryonic pLL neuromasts. Our results show that a fine-balance between primordium intrinsic properties and instructive interactions with the surrounding tissues is necessary to achieve proper organ morphogenesis and patterning. We speculate that this logic likely facilitates the accommodation of sensory modules to changing and diverse body plans.